Anthelminitic compounds and compositions and method of using thereof

The present disclosure relates to novel anthelmintic compounds of formula (I) and compositions containing the compounds: wherein, at least one of variables Y and Z is a bicyclic carbocyclyl or heterocyclyl group. Variables Y, X₁, X₂, X₃, X₄, X₅, X₆, X₇, X₈ and Z are as defined below. The disclosure also relates to parasiticidal compositions comprising the compounds, and methods and uses of the compounds for treating and preventing parasitic infections and infestations in animals.

Animals such as mammals and birds are often susceptible to parasite infestations/infections. These parasites may be ectoparasites, such as insects, and endoparasites such as nematodes and other worms. Domesticated animals, such as cats and dogs, are often infested with one or more of the following ectoparasites:

• fleas (e.g. Ctenocephalides spp., such as Ctenocephalides felis and the like);
• ticks (e.g. Rhipicephalus spp., Ixodes spp., Dermacentor spp., Amblyoma spp., and the like);
• mites (e.g. Demodex spp., Sarcoptes spp., Otodectes spp., and the like);
• lice (e.g. Trichodectes spp., Cheyletiella spp., Linognathus spp. and the like);
• mosquitoes (Aedes spp., Culex spp., Anopheles spp. and the like); and
• flies (Hematobia spp., Musca spp., Stomoxys spp., Dermatobia spp., Cochliomyia spp. and the like).

Fleas are a particular problem because not only do they adversely affect the health of the animal or human, but they also cause a great deal of psychological stress. Moreover, fleas may also transmit pathogenic agents to animals and humans, such as tapeworm (Dipylidium caninum).

Similarly, ticks are also harmful to the physical and psychological health of the animal or human. However, the most serious problem associated with ticks is that they are vectors of pathogenic agents in both humans and animals. Major diseases which may be transmitted by ticks include borrelioses (Lyme disease caused by Borrelia burgdorferi), babesioses (or piroplasmoses caused by Babesia spp.) and rickettsioses (e.g. Rocky Mountain spotted fever). Ticks also release toxins which cause inflammation or paralysis in the host. Occasionally, these toxins are fatal to the host.

Likewise, farm animals are also susceptible to parasite infestations. For example, cattle are affected by a large number of parasites. Parasites prevalent among cattle in some regions are ticks of the genus Rhipicephalus, especially those of the species microplus (cattle tick), decoloratus and annulatus. Ticks such as Rhipicephalus microplus (formerly Boophilus microplus) are difficult to control because they lay eggs in the pasture where farm animals graze. This species of ticks is considered a one-host tick and spends immature and adult stages on one animal before the female engorges and falls off the host to lay eggs in the environment. The life cycle of the tick is approximately three to four weeks. In addition to cattle, Rhipicephalus microplus may infest buffalo, horses, donkeys, goats, sheep, deer, pigs, and dogs. A heavy tick burden on animals can decrease production and damage hides as well as transmit diseases such as babesioses ("cattle fever") and anaplasmosis.

Animals and humans also suffer from endoparasitic infections including, for example, helminthiasis which is caused by of parasitic worms categorized as cestodes (tapeworm), nematodes (roundworm) and trematodes (flatworm or flukes). These parasites adversely affect the nutrition of the animal and cause severe economic losses in pigs, sheep, horses, and cattle as well as affecting domestic animals and poultry. Other parasites which occur in the gastrointestinal tract of animals and humans include Ancylostoma, Necator, Ascaris, Strongyloides, Trichinella, Capillaria, Toxocara, Toxascaris, Trichiris, Enterobius and parasites which are found in the blood or other tissues and organs such as filarial worms and the extra intestinal stages of Strogyloides, Toxocara and Trichinella.

Another endoparasite which seriously harms animals is Dirofilaria immitis, also known as Heartworm. The most common hosts are dogs and cats but other animals such as ferrets and raccoons may also be infected. The parasitic worm is transmitted by the mosquitoe bites, which carry the heartworm larvae. The adult worms live in the major blood vessels of the lung, causing inflamation of the blood vessels and potentially resulting in heart damage and early death. In advanced infections, the worms enter the heart as well.

Recently, anthelmintic compounds with activity against various endoparasitic species were reported in WO 2009/077527 A1, WO 2010/115688 A1, WO 2010/146083 A1 and EP 2 468 096 A1. Although many parasitic infections can be treated with known antiparasitic compounds and compositions, there is a need for new parasiticidal active agents and veterinary compositions and methods with improved efficacy, bioavailability, and spectrum of coverage to protect animals against endoparasites and/or ectoparasites. This invention addresses this need.

The present disclosure is directed to anthelmintic compounds of formulae (I), (IA), (IA-1): as described herein and compositions comprising the compounds in combination with a pharmaceutically acceptable carrier or diluent. In one aspect, the present invention provides an anthelmintic compound of formula (IA-1): wherein:

• Y is naphthyl, benzofuranyl, dihydrobenzofuranyl, quinolinyl, isoquinolinyl, tetrahydroquinolyl, tetrahydroisoquinolyl, indolyl, isoindolyl, benzothiophenyl, benzimidazolyl, or benzothiazolyl, each of which is optionally substituted by one or more of chloro, fluoro, bromo, CF₃, OCF₃, SCF₃ or SF₅;
• Z is phenyl optionally substituted by cyano, nitro, CF₃, SF₅, S(O)C₁-₃alkyl, S(O)₂-C₁-₃alkyl, S(O)C₁-₃haloalkyl or S(O)₂C₁-₃haloalkyl;
  • Ring A is one of L1, L13, L14 or L15:
  • Ring B is trans-cyclohexylene;
  • W is O;
  • X₁ is a bond or -CH₂-;
  • X₆ is -O-;
  • X₈ is a bond, -(CH₂)_n-, -O- or -NH-, wherein CH₂ and -NH- are optionally independently substituted with one or two substituents selected from the group consisting of halogen, C₁-₃alkyl and C₁-₃haloalkyl;
  • R₂ and R₃ are H;
  • R⁵ and R⁶ are each independently selected from hydrogen, C_1-3alkyl and C_1-3haloalkyl
  • n is 1; and
  • m is 0.

The present invention is also directed to methods for the treatment and prevention of a parasitic infection in an animal comprising administering at least one of the compounds of the invention to the animal. Also included in the present invention are uses of the compounds for the treatment and/or prevention of parasitic infections in animals and the use of the compounds in the preparation of a medicament for the treatment and/or prevention of a parasitic infection in an animal.

The compounds of the invention are intended to encompass racemic mixtures, specific stereoisomers and tautomeric forms of the compound. Another aspect of the invention is a salt form of the compound of the invention.

Another aspect of the invention are solid state forms of the compounds of the invention which consists of crystalline forms including single crystals, nanocrystals, co-crystals, molecular complexes, hydrates, anhydrates, solvates, desolvates, clathrates and inclusion complexes and non-crystalline forms including non-crystalline glass and non-crystalline amorphous forms. These and other embodiments are disclosed or are apparent from and encompassed by, the following Detailed Description.

The present invention provides novel and inventive anthelmintic compounds of formulae (IA-1) as described herein, and compositions comprising the compounds together with a pharmaceutically acceptable carrier or diluent. The compounds of the invention have been found to be highly efficacious against internal parasites (endoparasites) that cause harm to animals. In certain embodiments, the compounds of the invention may also be used to combat external parasites (ectoparasites) that cause harm to animals.

The compounds may be combined with one or more additional active agents in compositions to broaden the scope of coverage against both endoparasites and ectoparasites.

Also provided are methods and uses of the compounds and compositions for the treatment and/or prophylaxis of parasitic infections and infestations of animals, comprising administering an effective amount of a compound or composition of the invention to the animal.

Terms used herein will have their customary meaning in the art unless specified otherwise. The organic moieties mentioned in the definitions of the variables of formula (I) are - like the term halogen - collective terms for individual listings of the individual group members. The prefix C_n-C_m indicates in each case the possible number of carbon atoms in the group.

The term "animal" is used herein to include all mammals, birds and fish and also include all vertebrate animals. Animals include, but are not limited to, cats, dogs, cattle, chickens, cows, deer, goats, horses, llamas, pigs, sheep and yaks. It also includes an individual animal in all stages of development, including embryonic and fetal stages. In some embodiments, the animal will be a non-human animal.

Unless otherwise specifically noted or apparent by context, "active agent" or "active ingredient" or "therapeutic agent" as used in this specification, means an anthelmintic compound of the invention.

The term "fatty acid" refers to carboxylic acids having from 4 to 26 carbon atoms.

The terms "fatty alcohol" or "long-chain aliphatic alcohol" refer to aliphatic alcohols containing from 6 to 20 carbon atoms.

The term "alkyl" refers to saturated straight, branched, cyclic, primary, secondary or tertiary hydrocarbons, including those having 1 to 20 atoms. In some embodiments, alkyl groups will include C₁-C₁₂, C₁-C₁₀, C₁-C₈, C₁-C₆ or C₁-C₄ alkyl groups. Examples of C₁-C₁₀ alkyl include, but are not limited to, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, heptyl, octyl, 2-ethylhexyl, nonyl and decyl and their isomers. C₁-C₄-alkyl means for example methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl or 1,1-dimethylethyl.

The term "carbocyclyl" refers to carbon-containing ring systems, including both "cycloalkyl" and "aryl" groups as defined herein.

Cyclic alkyl groups or "cycloalkyl", which are encompassed by alkyl include those with 3 to 10 carbon atoms having single or multiple condensed rings. In some embodiments, cycloalkyl groups include C₄-C₇ or C₃-C₄ cyclic alkyl groups. Non-limiting examples of cycloalkyl groups include adamantyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and the like.

The alkyl groups described herein can be unsubstituted or substituted with one or more moieties selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, haloalkoxy, aryl, aryloxy, arylalkoxy, heteroaryl, heteroaryloxy, heteroarylalkoxy, halogen, haloalkyl, hydroxyl, hydroxyalkyl, carboxyl, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, acyl, acyloxy, sulfanyl, sulfamonyl, amino, alkyl- or dialkylamino, amido, arylamino, alkoxy, haloalkoxy, aryloxy, nitro, cyano, azido, thiol, imino, sulfonic acid; alkyl, haloalkyl or aryl sulfate; alkyl, haloalkyl or aryl sulfonyl; arylalkylsulfonyl; alkyl, haloalkyl or aryl sulfinyl; arylalkylsulfinyl; alkyl haloalkyl or aryl thio; arylalkylthio; heteroarylthio, heteroarylalkylthio, heteroarylsulfinyl, heteroarylalkylsulfinyl, heteroarylsulfonyl, heteroarylalkylsulfonyl, an alkyl, haloalkyl or aryl ester, phosphonyl, phosphinyl, phosphoryl, phosphine, thioester, thioether, acid halide, anhydride, oxime, hydrazine, carbamate, phosphoric acid, phosphate, phosphonate, or any other viable functional group that does not inhibit the biological activity of the compounds of the invention, either unprotected, or protected as necessary, as known to those skilled in the art, for example, as taught in Greene, et al., Protective Groups in Organic Synthesis, John Wiley and Sons, Third Edition, 1999.

Terms including the term "alkyl" such as "alkylcycloalkyl," "cycloalkylalkyl," "alkylamino," or "dialkylamino" will be understood to comprise an alkyl group as defined above linked to the other functional group, where the group is linked to the compound through the last group listed, as understood by those of skill in the art.

The term "alkenyl" refers to both straight and branched carbon chains which have at least one carbon-carbon double bond. In some embodiments, alkenyl groups may include C₂-C₂₀ alkenyl groups. In other embodiments, alkenyl includes C₂-C₁₂, C₂-C₁₀, C₂-C₈, C₂-C₆ or C₂-C₄ alkenyl groups. In one embodiment of alkenyl, the number of double bonds is 1-3, in another embodiment of alkenyl, the number of double bonds is one or two. Other ranges of carbon-carbon double bonds and carbon numbers are also contemplated depending on the location of the alkenyl moiety on the molecule. "C₂-C₁₀-alkenyl" groups may include more than one double bond in the chain. Examples include, but are not limited to, ethenyl, 1-propenyl, 2-propenyl, 1-methyl-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 2-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl; 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-1-butenyl, 2-methyl-1-butenyl, 3-methyl-1-butenyl, 1-methyl-2-butenyl, 2-methyl-2-butenyl, 3-methyl-2-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-ethyl-1-propenyl, 1-ethyl-2-propenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 2-methyl-1-pentenyl, 3-methyl-1-pentenyl, 4-methyl-1-pentenyl, 1-methyl-2-pentenyl, 2-methyl-2-pentenyl, 3-methyl-2-pentenyl, 4-methyl-2-pentenyl, 1-methyl-3-pentenyl, 2-methyl-3-pentenyl, 3-methyl-3-pentenyl, 4-methyl-3-pentenyl, 1-methyl-4-pentenyl, 2-methyl-4-pentenyl, 3-methyl-4-pentenyl, 4-methyl-4-pentenyl, 1,1-dimethyl-2-butenyl, 1,1-dimethyl-3-butenyl, 1,2-dimethyl-1-butenyl, 1,2-dimethyl-2-butenyl, 1,2-dimethyl-3-butenyl, 1,3-dimethyl-1-butenyl, 1,3-dimethyl-2-butenyl, 1,3-dimethyl-3-butenyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 3,3-dimethyl-1-butenyl, 3,3-dimethyl-2-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl, 1-ethyl-3-butenyl, 2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, 1,1,2-trimethyl-2-propenyl, 1-ethyl-1-methyl-2-propenyl, 1-ethyl-2-methyl-1-propenyl and 1-ethyl-2-methyl-2-propenyl.

"Alkynyl" refers to both straight and branched carbon chains which have at least one carbon-carbon triple bond. In one embodiment of alkynyl, the number of triple bonds is 1-3; in another embodiment of alkynyl, the number of triple bonds is one or two. In some embodiments, alkynyl groups include from C₂-C₂₀ alkynyl groups. In other embodiments, alkynyl groups may include C₂-C₁₂, C₂-C₁₀, C₂-C₈, C₂-C₆ or C₂-C₄ alkynyl groups. Other ranges of carbon-carbon triple bonds and carbon numbers are also contemplated depending on the location of the alkenyl moiety on the molecule. For example, the term "C₂-C₁₀-alkynyl" as used herein refers to a straight-chain or branched unsaturated hydrocarbon group having 2 to 10 carbon atoms and containing at least one triple bond, such as ethynyl, prop-1-yn-1-yl, prop-2-yn-1-yl, n-but-1-yn-1-yl, n-but-1-yn-3-yl, n-but-1-yn-4-yl, n-but-2-yn-1-yl, n-pent-1-yn-1-yl, n-pent-1-yn-3-yl, n-pent-1-yn-4-yl, n-pent-1-yn-5-yl, n-pent-2-yn-1-yl, n-pent-2-yn-4-yl, n-pent-2-yn-5-yl, 3-methylbut-1-yn-3-yl, 3-methylbut-1-yn-4-yl, n-hex-1-yn-1-yl, n-hex-1-yn-3-yl, n-hex-1-yn-4-yl, n-hex-1-yn-5-yl, n-hex-1-yn-6-yl, n-hex-2-yn-1-yl, n-hex-2-yn-4-yl, n-hex-2-yn-5-yl, n-hex-2-yn-6-yl, n-hex-3-yn-1-yl, n-hex-3-yn-2-yl, 3-methylpent-1-yn-1-yl, 3-methylpent-1-yn-3-yl, 3-methylpent-1-yn-4-yl, 3-methylpent-1-yn-5-yl, 4-methylpent-1-yn-1-yl, 4-methylpent-2-yn-4-yl or 4-methylpent-2-yn-5-yl and the like.

The term "haloalkyl" refers to an alkyl group, as defined herein, which is substituted by one or more halogen atoms. For example C₁-C₄-haloalkyl includes, but is not limited to, chloromethyl, bromomethyl, dichloromethyl, trichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, chlorofluoromethyl, dichlorofluoromethyl, chlorodifluoromethyl, 1-chloroethyl, 1-bromoethyl, 1-fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-chloro-2-fluoroethyl, 2-chloro-2,2-difluoroethyl, 2,2-dichloro-2-fluoroethyl, 2,2,2-trichloroethyl, pentafluoroethyl and the like.

The term "haloalkenyl" refers to an alkenyl group, as defined herein, which is substituted by one or more halogen atoms.

The term "haloalkynyl" refers to an alkynyl group, as defined herein, which is substituted by one or more halogen atoms.

"Alkoxy" refers to alkyl-O-, wherein alkyl is as defined above. Similarly, the terms "alkenyloxy," "alkynyloxy," "haloalkoxy," "haloalkenyloxy," "haloalkynyloxy," "cycloalkoxy," "cycloalkenyloxy," "halocycloalkoxy," and "halocycloalkenyloxy" refer to the groups alkenyl-O-, alkynyl-O-, haloalkyl-O-, haloalkenyl-O-, haloalkynyl-O-, cycloalkyl-O-, cycloalkenyl-O-, halocycloalkyl-O-, and halocycloalkenyl-O-, respectively, wherein alkenyl, alkynyl, haloalkyl, haloalkenyl, haloalkynyl, cycloalkyl, cycloalkenyl, halocycloalkyl, and halocycloalkenyl are as defined above. Examples of C₁-C₆-alkoxy include, but are not limited to, methoxy, ethoxy, C₂H₅-CH₂O-, (CH₃)₂CHO-, n-butoxy, C₂H₅-CH(CH₃)O-, (CH₃)₂CH-CH₂O-, (CH₃)₃CO-, n-pentoxy, 1-methylbutoxy, 2-methylbutoxy, 3-methylbutoxy, 1,1-dimethylpropoxy, 1,2-dimethylpropoxy, 2,2-dimethyl-propoxy, 1-ethylpropoxy, n-hexoxy, 1-methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1,1-dimethylbutoxy, 1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,2-dimethylbutoxy, 2,3-dimethylbutoxy, 3,3-dimethylbutoxy, 1-ethylbutoxy, 2-ethylbutoxy, 1,1,2-trimethylpropoxy, 1,2,2-trimethylpropoxy, 1-ethyl-1-methylpropoxy, 1-ethyl-2-methylpropoxy and the like.

The term "alkylthio" refers to alkyl-S-, wherein alkyl is as defined above. Similarly, the terms "haloalkylthio," "cycloalkylthio," and the like, refer to haloalkyl-S- and cycloalkylS- where haloalkyl and cycloalkyl are as defined above.

The term "halothio" refers to (halogen)₅-S-, wherein halogen is as defined above. An example of "halothio" is the group F₅S-.

The term "alkylsulfinyl" refers to alkyl-S(O)-, wherein alkyl is as defined above. Similarly, the term "haloalkylsulfinyl" refers to haloalkyl-S(O)- where haloalkyl is as defined above.

The term "alkylsulfonyl" refers to alkyl-S(O)₂-, wherein alkyl is as defined above. Similarly, the term "haloalkylsulfonyl" refers to haloalkyl-S(O)₂- where haloalkyl is as defined above.

The term alkylamino and dialkylamino refer to alkyl-NH- and (alkyl)₂N- where alkyl is as defined above. Similarly, the terms "haloalkylamino" refers to haloalkyl-NH- where haloalkyl is as defined above.

The terms "alkylcarbonyl," "alkoxycarbonyl," "alkylaminocarbonyl," and "dialkylaminocarbonyl" refer to alkyl-C(O)-, alkoxy-C(O)-, alkylamino-C(O)- and dialkylamino-C(O)- where alkyl, alkoxy, alkylamino and dialkylamino are as defined above. Similarly, the terms "haloalkylcarbonyl," "haloalkoxycarbonyl," "haloalkylaminocarbonyl," and "dihaloalkylaminocarbonyl" refer to the groups haloalkyl-C(O)-, haloalkoxy-C(O)-, haloalkylamino-C(O)- and dihaloalkylamino-C(O)- where haloalkyl, haloalkoxy, haloalkylamino and dihaloalkylamino are as defined above.

"Aryl" refers to a monovalent aromatic carbocyclic group of from 6 to 14 carbon atoms having a single ring or multiple condensed rings. In some embodiments, aryl groups include C₆-C₁₀ aryl groups. Aryl groups include, but are not limited to, phenyl, biphenyl, naphthyl, tetrahydronaphthyl, phenylcyclopropyl, biphenylene, fluorene, anthracene, acenaphthene, phenanthrene and indanyl. Examples of bicyclic aryl groups include naphthyl and indanyl. Aryl groups may be unsubstituted or substituted by one or more moieties selected from halogen, cyano, nitro, hydroxy, mercapto, amino, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, haloalkyl, haloalkenyl, haloalkynyl, halocycloalkyl, halocycloalkenyl, alkoxy, alkenyloxy, alkynyloxy, haloalkoxy, haloalkenyloxy, haloalkynyloxy, cycloalkoxy, cycloalkenyloxy, halocycloalkoxy, halocycloalkenyloxy, alkylthio, haloalkylthio, cycloalkylthio, halocycloalkylthio, alkylsulfinyl, alkenylsulfinyl, alkynyl-sulfinyl, haloalkylsulfinyl, haloalkenylsulfinyl, haloalkynylsulfinyl, alkylsulfonyl, alkenylsulfonyl, alkynylsulfonyl, haloalkyl-sulfonyl, haloalkenylsulfonyl, haloalkynylsulfonyl, alkylamino, alkenylamino, alkynylamino, di(alkyl)amino, di(alkenyl)-amino, di(alkynyl)amino, or trialkylsilyl.

The terms "aralkyl" or "arylalkyl" refers to an aryl group that is bonded to the parent compound through a diradical alkylene bridge, (-CH₂-)_n, where n is 1-12 and where "aryl" is as defined above.

"Heteroaryl" refers to a monovalent aromatic group of from 1 to 15 carbon atoms, preferably from 1 to 10 carbon atoms, having one or more oxygen, nitrogen, and sulfur heteroatoms within the ring, preferably 1 to 4 heteroatoms, or 1 to 3 heteroatoms. The nitrogen and sulfur heteroatoms may optionally be oxidized. Such heteroaryl groups can have a single ring (e.g., pyridyl or furyl) or multiple condensed rings provided that the point of attachment is through a heteroaryl ring atom. Preferred heteroaryls include pyridyl, piridazinyl, pyrimidinyl, pyrazinyl, triazinyl, pyrrolyl, indolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, furanyl, thiophenyl, pyrrolyl, imidazolyl, oxazolyl, isoxazolyl, isothiazolyl, pyrazolyl, benzofuranyl, dihydrobenzofuranyl and benzothiophenyl. Heteroaryl rings may be unsubstituted or substituted by one or more moieties as described for aryl above.

"Heterocyclyl," "heterocyclic" or "heterocyclo" refer to fully saturated or unsaturated, cyclic groups, for example, 3 to 8 membered monocyclic or 4 to 7 membered monocyclic; 7 to 11 membered bicyclic, or 10 to 15 membered tricyclic ring systems, which have one or more oxygen, sulfur or nitrogen heteroatoms in ring, preferably 1 to 4 or 1 to 3 heteroatoms. The nitrogen and sulfur heteroatoms may optionally be oxidized and the nitrogen heteroatoms may optionally be quaternized. The heterocyclic group may be attached at any heteroatom or carbon atom of the ring or ring system and may be unsubstituted or substituted by one or more moieties as described for aryl groups above.

Exemplary monocyclic heterocyclic groups include, but are not limited to, pyrrolidinyl, pyrrolyl, pyrazolyl, oxetanyl, pyrazolinyl, imidazolyl, imidazolinyl, imidazolidinyl, oxazolyl, oxazolidinyl, isoxazolinyl, isoxazolyl, thiazolyl, thiadiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, furyl, tetrahydrofuranyl, thienyl, oxadiazolyl, piperidinyl, piperazinyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolodinyl, 2-oxoazepinyl, azepinyl, 4-piperidonyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, tetrahydropyranyl, morpholinyl, thiamorpholinyl, thiamorpholinyl sulfoxide, thiamorpholinyl sulfone, 1,3-dioxolane and tetrahydro-1,1-dioxothienyl, triazolyl, triazinyl, and the like.

Exemplary bicyclic heterocyclic groups include, but are not limited to, indolyl, isoindolyl, benzothiazolyl, benzoxazolyl, benz[d]isoxazolyl, benzotriazolyl, benzodioxolyl, benzothienyl, quinuclidinyl, quinazolinyl, quinoxalinyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzopyranyl, indolizinyl, benzofuranyl, dihydrobenzofuranyl, chromonyl, coumarinyl, cinnolinyl, indazolyl, pyrrolopyridyl, phthalazinyl, 1,2,3-benzotriazinyl, 1,2,4-benzotriazinyl, furopyridinyl (such as furo[2,3-c]pyridinyl, furo[3,2-b]pyridinyl]or furo[2,3-b]pyridinyl), dihydroisoindolyl, dihydroquinazolinyl (such as 3,4-dihydro-4-oxo-quinazolinyl), tetrahydroquinolinyl, tetrahydroisoquinolinyl, and the like.

Exemplary tricyclic heterocyclic groups include carbazolyl, benzidolyl, phenanthrolinyl, acridinyl, phenanthridinyl, xanthenyl, and the like. Halogen means the atoms fluorine, chlorine, bromine and iodine. The designation of "halo" (e.g. as illustrated in the term haloalkyl) refers to all degrees of substitutions from a single substitution to a perhalo substitution (e.g. as illustrated with methyl as chloromethyl (-CH₂Cl), dichloromethyl (-CHCl₂), trichloromethyl (-CCl₃)).

In a first aspect of the disclosure, an anthelmintic compound of Formula (I) is provided wherein:

• Y and Z are independently a bicyclic carbocyclic or a bicyclic heterocyclic group optionally substituted by one or more of halogen, nitro, cyano, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylcarbonyl, haloalkylcarbonyl, alkoxycarbonyl, haloalkoxycarbonyl, aminocarbonyl, alkyl- or dialkylaminocarbonyl, alkylthio, halothio, haloalkylthio, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl, haloalkylsulfonyl, aryl, aryloxy, arylalkoxy, arylthio, arylalkylthio, arylsulfinyl, arylsulfonyl, arylalkylsulfinyl, arylalkylsulfonyl, heteroaryl, heteroaryloxy, heteroarylalkoxy, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, heteroarylalkylthio, heteroarylalkylsulfinyl or heteroarylalkylsulfonyl; or
• one of Y or Z is a bicyclic carbocyclic or a bicyclic heterocyclic group optionally substituted by one or more of halogen, nitro, cyano, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylcarbonyl, haloalkylcarbonyl, alkoxycarbonyl, haloalkoxycarbonyl, aminocarbonyl, alkyl- or dialkylaminocarbonyl, alkylthio, halothio, haloalkylthio, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl, haloalkylsulfonyl, aryl, aryloxy, arylalkoxy, arylthio, arylalkylthio, arylsulfinyl, arylsulfonyl, arylalkylsulfinyl, arylalkylsulfonyl, heteroaryl, heteroaryloxy, heteroarylalkoxy, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, heteroarylalkylthio, heteroarylalkylsulfinyl or heteroarylalkylsulfonyl; and the other of Y or Z is alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, heterocyclyl or heteroaryl;
• wherein the alkyl, alkenyl, alkynyl, cycloalkyl, phenyl, heterocyclyl and heteroaryl groups are optionally substituted with one or more substituents independently selected from the group consisting of halogen, nitro, cyano, alkyl, haloalkyl, hydroxy, hydroxyalkyl, amino, alkyl- or dialkylamino, aminoalkyl, alkoxy, haloalkoxy, alkylcarbonyl, haloalkylcarbonyl, alkoxycarbonyl, haloalkoxycarbonyl, aminocarbonyl, alkyl- or dialkylaminocarbonyl, alkylthio, halothio, haloalkylthio, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl, haloalkylsulfonyl, aryl, aryloxy, arylalkoxy, arylthio, arylalkylthio, arylsulfinyl, arylsulfonyl, arylalkylsulfinyl, arylalkylsulfonyl, heteroaryl, heteroaryloxy, heteroarylalkoxy, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, heteroarylalkylthio, heteroarylalkylsulfinyl and heteroarylalkylsulfonyl;
• X₁ is a bond, -O-, -C(O)-, -C(S)-, -NH-, -S, -S(O), -S(O)₂-,-NHS(O)-, -S(O)-NH-, -NHSO₂-, -SO₂NH-, -(CH₂)n- where n is 1 to 3, -C(O)-CH₂-, -CH₂-C(O)-, -O-CH₂-, -CH₂-O-, -NHCH₂-, -CH₂-NH-, -S-CH₂-, -CH₂-S-, -S(O)-CH₂-, -CH₂-S(O)-, -S(O)₂-CH₂-, or -CH₂-S(O)₂-, wherein each NH-, -NHS(O)-, -S(O)-NH-, -NHSO₂-, -SO₂NH-, -(CH₂)_n, -C(O)CH₂-, -CH₂-C(O)-, -O-CH₂-, -CH₂-O, -NH-CH₂, -CH₂-NH-, -S-CH₂-, -CH₂-S-, -S(O)-CH₂-, -CH₂-S(O)-, -S(O)₂-CH₂- and -CH₂-S(O)₂- are optionally substituted with oxo (=O) or one or more halogen, cyano, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, cycloalkyl or aryl groups;
• X₂ is a linker selected from a C₁-C₈-alkylene group, a C₂-C₈-alkenylene group, a C₂-C₈-alkynylene group, a 3-8 membered carbocyclylene and 3-8 membered heterocyclylene group, wherein the 3-8 membered heterocyclylene group contains one to four nitrogen, oxygen or sulfur atoms, and wherein one to three of the carbon atoms in the C₁-C₈-alkylene group, the C₂-C₈-alkenylene group and the C₂-C₈-alkynylene group may be replaced by a nitrogen, an oxygen or sulfur atom; and wherein the C₁-C₈-alkylene group, the C₂-C₈-alkenylene group, the C₂-C₈-alkynylene group, the 3-8 membered carbocyclylene and the 3-8 membered heterocyclylene group are optionally substituted with one or more substituents independently selected from halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylthio, haloalkylthio, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, and oxo (=O);
• X₃ is a diradical group selected from the group consisting of a bond, -(CH₂)_n- where n is 1 to 3, -O-, -C(S)-, -C(O)-, -S(O)-, -S(O)₂-, and an oxetane group (4-membered ring containing one oxygen), wherein X₂ and X₄ may be bonded to any carbon atom of the oxetane group; and wherein each -CH₂- in the -(CH₂)_n- group is optionally substituted with one or two substituents independently selected from the group consisting of halogen, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, carbocyclyl and halocarbocyclyl;
• X₄ is a bond, -(CH₂)_n- where n is 1 to 3, carbocyclylene or heterocyclylene, wherein the -CH₂-, the carbocyclylene and the heterocyclylene groups are optionally substituted with one or more substituents independently selected from the group consisting of halogen, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, carbocyclyl and halocarbocyclyl;
• X₅ is absent or is a bond, -(CH₂)_n where n is 1 to 3, carbocyclylene or heterocyclylene, wherein each -CH₂- in the -(CH₂)_n group, the carbocyclylene and the heterocyclylene groups are optionally substituted with one or more substituents independently selected from the group consisting of halogen, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, carbocyclyl and halocarbocyclyl;
• X₆ is -(CH₂)_n-where n is 1 to 3, -O-, -C(O)-, -C(S)-, -S-, -S(O)-, -S(O)₂-, -NH-, -C(O)-NH-, -C(S)-NH-, -NH-C(O)-, -NH-C(S)-, wherein each -CH₂- in the -(CH₂)_n- group, -NH-, -C(O)-NH-, -C(S)-NH-, -NH-C(O)-, -NH-C(S)- are optionally substituted with one or more substituents independently selected from the group consisting of halogen, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, carbocyclyl, halocarbocyclyl, carbocyclylalkyl and halocarbocyclylalkyl;
• X₇ is a bond, -(CH₂)_n- where n is 1 to 3, alkenylene, alkynylene, carbocyclylene or heterocyclylene, wherein each CH₂ in -(CH₂)_n- , alkenylene, alkynylene, carbocyclylene and heterocyclylene is optionally substituted with one or more halogen, hydroxy, hydroxyalkyl, alkyl, haloalkyl, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino or aminoalkyl group; and
• X₈ is a bond, -(CH₂)_n where n is 1 to 3, -O-, -C(O)-, -S-, -S(O)-, -S(O)₂-, -NHS(O)-, - S(O)-NH-, -NHSO₂-, -SO₂NH- or -NH-, wherein each CH₂ in -(CH₂)_n- , -NHS(O)-, -S(O)-NH-, -NHSO₂-, -SO₂NH- or -NH- is optionally independently substituted with one or two substituents selected from the group consisting of halogen, hydroxy, amino, alkylamino, dialkylamino, hydroxyalkyl, aminoalkyl, alkyl, haloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, alkoxyalkyl, carbocyclyl, halocarbocyclyl, carbocyclylalkyl and halocarbocyclylalkyl.

In one embodiment of this disclosure, at least one of Y or Z is an optionally substituted bicyclic carbocyclic group. In another, at least one of Y or Z is an optionally substituted bicyclic aromatic carbocyclic group. In still another, at least one of Y or Z is an optionally substituted non-aromatic bicyclic carbocyclic group. In still another embodiment, at least one of Y or Z is optionally substituted naphthyl, tetrahydronaphthyl or indanyl.

In another embodiment of this disclosure, at least one of Y or Z is a bicyclic heterocyclic group. In another, at least one of Y or Z is an optionally substituted bicyclic heteroaryl group. In still another, at least one of Y or Z is optionally substituted indolyl, benzothiazolyl, benzoxazolyl, benzodioxolyl, benzothienyl, quinuclidinyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, tetra-hydroisoquinolinyl, benzimidazolyl, benzopyranyl, indolizinyl, benzofuranyl, dihydrobenzofuranyl, chromonyl, coumarinyl, benzopyranyl, cinnolinyl, quinoxalinyl, indazolyl, pyrrolopyridyl, furopyridinyl (such as furo[2,3-c]pyridinyl, furo[3,2-b]pyridinyl]or furo[2,3-b]pyridinyl), dihydroisoindolyl or dihydroquinazolinyl (such as 3,4-dihydro-4-oxo-quinazolinyl).

In one embodiment of this disclosure, X₁ is a bond, -C(O)-, -CH₂-, -CH₂CH₂-, -C(O)-CH₂-, - CH₂-C(O), -O-CH₂-, -CH₂-O-, -NHCH₂- or -CH₂-NH-, wherein each -CH₂-, -CH₂CH₂-, -C(O)CH₂-, - CH₂-C(O)-, -O-CH₂-, -CH₂-O, -NH-CH₂, -CH₂-NH- are optionally substituted with one or more halogen, alkyl, haloalkyl or cycloalkyl groups.

In another embodiment of this disclosure, X₁ is -NH-, -NHS(O)-, -S(O)-NH-, - NHSO₂- or -SO₂NH-.

In another embodiment of this disclosure, X₁ is a bond, -CH₂- or -CH₂CH₂-, wherein each -CH₂- or -CH₂CH₂-is optionally substituted with one or more halogen, alkyl or haloalkyl groups.

In one embodiment of this disclosure, X₂ is a C₁-C₈-alkylene group, a 3-8 membered carbocyclylene or a 3-8 membered heterocyclylene group containing one to four nitrogen, oxygen or sulfur heteroatoms, wherein one or more of the carbon atoms in the C₁-C₈-alkylene group may be replaced by a nitrogen, oxygen or sulfur atom; and wherein the C₁-C₈-alkylene group, the 3-8 membered carbocyclylene and the 3-8 membered heterocyclylene group are optionally substituted with one or more substituents independently selected from halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl and oxo (=O).

In one preferred embodiment of this disclosure, X₂ is -C(=O)- or optionally substituted C₁-C_3-alkylene.

In another embodiment of this disclosure, X₂ comprises a chain of from 3 to 6 atoms (as an acyclic chain or part of a ring) that bridges X₁ to X₃, wherein 1 or 2 of the chain atoms are nitrogen. In this embodiment of this disclosure, the nitrogen atoms in X₂ are typically bonded to X₁ and/or X₃.

In yet another embodiment of this disclosure, X₂ comprises a chain of from 3 to 6 atoms (as an acyclic chain or as part of a ring) that bridges X₁ to X₃, wherein 1 or 2 of the chain atoms are nitrogen and wherein one or more of the alkylene groups in the chain are substituted with oxo (=O).

In another embodiment of this disclosure, X₂ is a 3-8 membered heterocyclylene group containing at least one nitrogen atom. In still another, X₂ is a heterocyclylene group containing at least two nitrogen atoms. In yet another, X₂ is a 5- or 6-membered heterocyclylene group containing one or two nitrogen atoms.

In certain preferred embodiments of this disclosure, X₂ and/or X₇ are selected from one of the linkers L to L 18 in Table 1 below, wherein variables R and R' are each independently hydrogen, alkyl, haloalkyl or arylalkyl; R₂ and R₃ are independently hydrogen, halogen, cyano, alkyl, haloalkyl or carbocyclyl; R₄ is H, OH, halogen or C_1-3alkyl; R₅, R₆, R₇ and R₈ are independently hydrogen, C_1-3alkyl or C_1-3haloalkyl; W and W' are each independently O or S; and each linker L1 to L18 in the table may be substituted by one or more of halogen, cyano, C₁-C₆alkyl, hydroxy, thiol, C₁-C₆alkoxy, oxo or thiocarbonyl.

It will be understood that the X₂ and X₇ linkers presented in Table 1 may be bonded to X₁ and/or X₃ or X₆ and/or X₈ at any possible atom in the linker group. Typically, when the X₂ and/or the X₇ linker contains one or more nitrogen atoms, the nitrogen atom(s) will be bonded to X₁ and/or X₃ or X₆ and/or X₇.

In one embodiment of this disclosure, X₂ and/or X₇ is L1. In another preferred embodiment of this disclosure, X₂ and/or X₇ is L2. In yet another preferred embodiment of this disclosure, X₂ and/or X₇ is L11 or L12. In another, X₂ and/or X₇ is L 13 or L14. In still another, X₂ and/or X₇ is L13 where the R₆ and R₇ groups are in a trans relationship to each other. In yet another, X₂ and/or X₇ are L13 where the R₆ and R₇ groups are in a cis-relationship to each other. In another embodiment, X₂ and/or X₇ are L14 where the R₆ and R₇ groups are in a trans-relationship to each other. In still another, X₂ and/or X₇ are L14 where the R₆ and R₇ are in a cis-relationship to each other. In yet another, X₂ and/or X₇ are L15 where the R₆ and R₇ are trans to each other. In still another, X₂ and/or X₇ are L15 where R₆ and R₇ are cis- to each other. In still another, X₂ and/or X₇ are L16, L17 or L18.

In certain embodiments of this disclosure, X₃ is a bond, -(CH₂)_n where n is 1 to 3, - C(S)- or -C(O)-, wherein each carbon atom in the -(CH₂)_n group is optionally substituted with one or two substituents independently selected from the group consisting of halogen, alkyl or haloalkyl. In one preferred embodiment of this disclosure, X₃ is -C(O)-. In another preferred embodiment of this disclosure, X₃ is -CH₂CH₂- or -CH₂CH₂CH₂- wherein each of the carbon atoms may be substituted by one or two methyl groups. In yet another embodiment of this disclosure, X₃ is an oxetane group.

In one embodiment of this disclosure, X₄ is a bond. In another, X₄ is -(CH₂)_n- where n is 1 or 2, wherein each -CH₂- is optionally independently substituted with one or two substituents selected from the group consisting of halogen, alkyl, haloalkyl and carbocyclyl;

In another embodiment of this disclosure, X₅ is a bond or -(CH₂)_n- where n is 1 or 2 and wherein each -CH₂- in the -(CH₂)_n group is optionally independently substituted with one or two halogen, alkyl, haloalkyl, or carbocyclyl groups;

In yet another embodiment of this disclosure of formula (I), X₆ is -(CH₂)_n where n is 1 or 2, -O-, -C(O)-, -S-, -S(O)-, -S(O)₂- or -NH-, wherein each -CH₂- in the -(CH₂)_n- group or the NH, is optionally independently substituted with one or two substituents is selected from the group consisting of halogen, alkyl, haloalkyl and carbocyclyl. In one preferred embodiment of this disclosure, X₆ is CH₂. In another preferred embodiment of this disclosure, X₆ is -O-.

In another embodiment of this disclosure of formula (I), X₇ is a bond, -(CH₂)_n where n is 1 to 3, carbocyclylene or heterocyclylene, wherein each CH₂ in -(CH₂)_n-, carbocyclylene and heterocyclylene is optionally substituted with one or more halogen, alkyl, haloalkyl, hydroxy, hydroxyalkyl, alkoxy, haloalkoxy, amino, alkylamino or dialkylamino or aminoalkyl. In another embodiment, X₇ is a 5- or 6-membered carbocyclylene group such as cyclohexylene or cyclopentylene. In yet another, X₇ is a phenylene group.

In yet another embodiment of this disclosure of formula (I), X₈ is absent or is a bond, -(CH₂)_n where n is 1 to 3, -O-, -C(O)- or -NH-, wherein each CH₂ in -(CH₂)_n- and the -NH- is optionally independently substituted with one or two substituents selected from the group consisting of halogen, alkyl, and haloalkyl. In one particularly preferred embodiment of this disclosure, X₈ is -NH-. In another, X₈ is -C(O)-. In yet another preferred embodiment of this disclosure, X₈ is -CH₂-, -CF₂-, - CH(CH₃)- or -C(CH₃)₂-. In still another, X₈ is -NHS(O)-, -S(O)-NH-, -NHSO₂- or -SO₂NH-.

In one aspect of the disclosure, the compounds of formula (I) have the structure (IA) shown below:

Wherein variables Y, X₁, X₈ and Z are as defined for formula (I) above, Ring A and Ring B are independently a 3 to 8-membered monocyclic or a 7 to 11-membered bicyclic carbocyclylene or heterocyclylene ring, wherein the heterocyclic ring contains 1 to 4 heteroatoms selected from N, O and S; and the Linker is the segment -X₃-X₄-X₅-X₆- where X₃, X₄, X₅ and X₆ are as defined for formula (I).

In one embodiment of this disclosure of formula (IA), Ring A is one of L1 to L10; or L13 to L18 as defined in Table 1, which may optionally be substituted with halogen, alkyl or haloalkyl. In another embodiment, Ring A is cyclohexylene or phenylene, which may optionally be substituted with halogen, alkyl or haloalkyl. In another embodiment of this disclosure of formula (IA), Ring B is cyclohexylene or phenylene, which may optionally be substituted with halogen, alkyl or haloalkyl. In still another, Ring B is one of L1 to L10; or L13 to L18 as defined in Table 1, which may optionally be substituted with halogen, alkyl or haloalkyl.

In one embodiment of this disclosure of formula (IA), X₁ is a bond, an optionally substituted -(CH₂)_n- where n is 1 to 3, or -C(O)-.

In another embodiment of this disclosure of formula (IA), X₈ is -C(O)-, -NH- or - (CH₂)_n- where n is 1 to 3, wherein the each CH₂ in -(CH₂)_n- or the -NH- may optionally be substituted.

In still another embodiment of this disclosure of formula (IA), Y and/or Z is phenyl or naphthyl optionally substituted with one or more of halogen, nitro, cyano, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylthio, halothio, haloalkylthio, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl, haloalkylsulfonyl, aryl, aryloxy, arylalkoxy, arylthio, arylalkylthio, arylsulfinyl, arylsulfonyl, arylalkylsulfinyl, arylalkylsulfonyl, heteroaryl, heteroaryloxy, heteroarylalkoxy, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, heteroarylalkylthio, heteroarylalkylsulfinyl or heteroarylalkylsulfonyl, with the proviso that at least one or Y or Z is naphthyl.

In yet another embodiment of this disclosure of formula (IA), Y and/or Z are independently phenyl, benzofuranyl, dihydrobenzofuranyl, quinolinyl, isoquinolinyl, tetrahydroquinolyl, tetrahydroisoquinolyl, indolyl, isoindolyl, benzothiophenyl, benzimidazolyl, or benzothiazolyl, each of which is optionally substituted by one or more halogen, nitro, cyano, hydroxy, hydroxyalkyl, amino, alkylamino, dialkylamino, aminoalkyl, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylthio, halothio, haloalkylthio, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl, haloalkylsulfonyl, aryl, aryloxy, arylalkoxy, arylthio, arylalkylthio, arylsulfinyl, arylsulfonyl, arylalkylsulfinyl, arylalkylsulfonyl, heteroaryl, heteroaryloxy, heteroarylalkoxy, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, heteroarylalkylthio, heteroarylalkylsulfinyl or heteroarylalkylsulfonyl, with the proviso that at least one of Y or Z is a bicyclic ring.

The present invention provides the compound having the structure of formula (IA-1) shown below: wherein:

• Y is naphthyl, benzofuranyl, dihydrobenzofuranyl, quinolinyl, isoquinolinyl, tetrahydroquinolyl, tetrahydroisoquinolyl, indolyl, isoindolyl, benzothiophenyl, benzimidazolyl, or benzothiazolyl, each of which is optionally substituted by one or more of chloro, fluoro, bromo, CF₃, OCF₃, SCF₃ or SF₅;
• Z is phenyl optionally substituted by cyano, nitro, CF₃, SF₅, S(O)C₁-₃alkyl, S(O)₂-C₁-₃alkyl, S(O)C₁-₃haloalkyl or S(O)₂C₁-₃haloalkyl;
  • Ring A is one of L1, L13, L14 or L15:
  • Ring B is trans-cyclohexylene;
  • W is O;
  • X₁ is a bond or -CH₂-;
  • X₆ is -O-;
  • X₈ is a bond, -(CH₂)_n-, -O- or -NH-, wherein CH₂ and -NH- are optionally independently substituted with one or two substituents selected from the group consisting of halogen, C₁-₃alkyl and C₁-₃haloalkyl;
  • R₂ and R₃ are H;
  • R⁵ and R⁶ are each independently selected from hydrogen, C_1-3alkyl and C_1-3haloalkyl
  • n is 1; and
  • m is 0.

In other embodiments of formula (IA-1), the invention provides the compounds in Table 2 below:

The compounds of the invention were found to exhibit superior permeability compared with prior art compounds. For an orally-dosed compound the permeability of a compound accross the epithelium cells along the gastrointestinal tract is an important limiting factor for the oral absorption and systemic availability of the compound. Thus, the permeability of a systemically-acting compound is a feature that can significantly impact the efficacy of a compound against internal and/or external parasites when administered orally or topically.

In one embodiment, the compounds of the invention exhibit surprisingly improved permeability compared with the compounds of the prior art having only monocyclic rings at the position corresponding to Y and/or Z (for example compounds of WO 2009/077527 and EP 2468096). The significantly higher permeability of the compounds of the invention is expected to result in higher in vivo efficacy against internal parasites such as nematodes and external parasites that consume blood meals. This is because the increased permeability accross the mammalian gut enhances the amount of the active compounds present in the blood circulation for delivery and uptake at the required sites. Furthermore, the increased permeability of the compounds is likely to result in increased permeability accross the nematode tissue. In addition, increased permeability of the active compounds may result in improved transdermal passage of the compounds into the bloodstream following topical administration.

In one embodiment, the compounds of the invention exhibit about 20% to about 30% higher permeability than the prior art compounds. In another embodiment, the compounds of the invention exhibit about 40% to about 60% or about 50% to about 70% higher permeability than the prior art compounds. In still other embodiments, the compounds of the invention exhibit about 60% to about 100% higher permeability. In yet other embodiments, the compounds of the invention exhibit about about 20% to about 50% or about 30% to about 75% higher permeability compared with the prior art compounds. In yet other embodiments, the compounds of the invention exhibit about 50% to about 100% higher permeability compared with the prior art compounds.

In other embodiments, the compounds of the invention exhibit about 50% to about 500% greater permeability than the prior art compounds. In other embodiments, the compounds of the invention exhibit about 100% to about 500% greater permeability than the prior art compounds. In yet other embodiments, the compounds of the invention exhibit about 200% to about 400% greater permeability. In other embodiments, the compounds of the invention exhibit In yet other embodiments, the compounds of the invention exhibit about 100% to about 300% higher permeability or about 200% to about 300% greater permeability than the prior art compounds. In yet other embodiments, the compounds of the invention exhibit about 100% to about 200% higher permeability compared with the prior art compounds. In other embodiments, the compounds of the invention exhibit about 300% to about 500% higher permeability or about 400% to about 500% higher permeability compared with the prior art compounds.

In another aspect, the invention provides parasiticidal compositions which comprise at least one anthelmintic compound of formula (I) of the invention and a pharmaceutically acceptable carrier. The composition of the invention can also be in a variety of forms which include, but are not limited to, oral formulations, injectable formulations, and topical, dermal or subdermal formulations. The formulations are intended to be administered to an animal which includes but is not limited to mammals, birds and fish. Examples of mammals include but are not limited to humans, cattle, sheep, goats, llamas, alpacas, pigs, horses, donkeys, dogs, cats and other livestock or domestic mammals. Examples of birds include turkeys, chickens, ostriches and other livestock or domestic birds.

The composition of the invention may be in a form suitable for oral use, for example, as baits (see, e.g., U.S. Patent No. 4,564,631), dietary supplements, troches, lozenges, chewables, tablets, hard or soft capsules, emulsions, aqueous or oily suspensions, aqueous or oily solutions, oral drench formulations, dispersible powders or granules, premixes, syrups or elixirs, enteric formulations or pastes. Compositions intended for oral use may be prepared according to any method known in the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, bittering agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations.

Tablets may contain the active ingredient in admixture with non-toxic, pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be, for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example, magnesium stearate, stearic acid or talc, the tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated by the technique described in U.S. Patent Nos. 4,256,108; 4,166,452; and 4,265,874 to form osmotic therapeutic tablets for controlled release.

Formulations for oral use may be hard gelatin capsules, wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin. Capsules may also be soft gelatin capsules, wherein the active ingredient is mixed with water or miscible solvents such as propylene glycol, PEGs and ethanol, or an oil medium, for example peanut oil, liquid paraffin, or olive oil.

The compositions of the invention may also be in the form of oil-in-water or water-in-oil emulsions. The oily phase may be a vegetable oil, for example, olive oil or arachis oil, or a mineral oil, for example, liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring phosphatides, for example, soybean, lecithin, and esters or partial esters derived from fatty acids and hexitol anhydrides, for example, sorbitan monoleate, and condensation products of the said partial esters with ethylene oxide, for example, polyoxyethylene sorbitan monooleate. The emulsions may also contain sweetening agents, bittering agents, flavoring agents, and/or preservatives.

In one embodiment of the formulation, the composition of the invention is in the form of a microemulsion. Microemulsions are well suited as the liquid carrier vehicle. Microemulsions are quaternary systems comprising an aqueous phase, an oily phase, a surfactant and a co-surfactant. They are translucent and isotropic liquids.

Microemulsions are composed of stable dispersions of microdroplets of the aqueous phase in the oily phase or conversely of microdroplets of the oily phase in the aqueous phase. The size of these microdroplets is less than 200 nm (1000 to 100,000 nm for emulsions). The interfacial film is composed of an alternation of surface-active (SA) and co-surface-active (Co-SA) molecules which, by lowering the interfacial tension, allows the microemulsion to be formed spontaneously.

In one embodiment of the oily phase, the oily phase can be formed from mineral or vegetable oils, from unsaturated polyglycosylated glycerides or from triglycerides, or alternatively from mixtures of such compounds. In one embodiment of the oily phase, the oily phase comprises of triglycerides; in another embodiment of the oily phase, the triglycerides are medium-chain triglycerides, for example C₈-C₁₀ caprylic/capric triglyceride. In another embodiment of the oily phase will represent a % v/v range selected from the group consisting of about 2 to about 15%; about 7 to about 10%; and about 8 to about 9% v/v of the microemulsion.

The aqueous phase includes, for example water or glycol derivatives, such as propylene glycol, glycol ethers, polyethylene glycols or glycerol. In one embodiment of the glycol derivatives, the glycol is selected from the group consisting of propylene glycol, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether and mixtures thereof. Generally, the aqueous phase will represent a proportion from about 1 to about 4% v/v in the microemulsion.

Surfactants for the microemulsion include diethylene glycol monoethyl ether, dipropyelene glycol monomethyl ether, polyglycolized C₈-C₁₀ glycerides or polyglyceryl-6 dioleate. In addition to these surfactants, the co-surfactants include short-chain alcohols, such as ethanol and propanol.

Some compounds are common to the three components discussed above, i.e., aqueous phase, surfactant and co-surfactant. However, it is well within the skill level of the practitioner to use different compounds for each component of the same formulation. In one embodiment for the amount of surfactant/co-surfactant, the co-surfactant to surfactant ratio will be from about 1/7 to about 1/2. In another embodiment for the amount of co-surfactant, there will be from about 25 to about 75% v/v of surfactant and from about 10 to about 55% v/v of co-surfactant in the microemulsion.

Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil, for example, arachis oil, olive oil, sesame oil or coconut oil, or in mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example, beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as sucrose, saccharin or aspartame, bittering agents, and flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid, or other known preservatives.

Aqueous suspensions may contain the active material in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example, sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example, heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide, with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl, p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents and/or bittering agents, such as those set forth above.

Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example, sweetening, bittering, flavoring and coloring agents, may also be present.

Syrups and elixirs may be formulated with sweetening agents, for example, glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative, flavoring agent(s) and/or coloring agent(s).

In another embodiment of the invention, the composition can be in paste form. Examples of embodiments in a paste form include but are not limited to those described in U.S. Patent Nos. 6,787,342 and 7,001,889. In addition to the anthelmintic compounds of the invention, the paste can also contain fumed silica; a viscosity modifier; a carrier; optionally, an absorbent; and optionally, a colorant, stabilizer, surfactant, or preservative.

The process for preparing a paste formulation comprises the steps of:

1. (a) dissolving or dispersing the anthelmintic compound into the carrier by mixing;
2. (b) adding the fumed silica to the carrier containing the dissolved anthelmintic compound and mixing until the silica is dispersed in the carrier;
3. (c) allowing the intermediate formed in (b) to settle for a time sufficient in order to allow the air entrapped during step (b) to escape; and
4. (d) adding the viscosity modifier to the intermediate with mixing to produce a uniform paste.

The above steps are illustrative, but not limiting. For example, step (a) can be the last step. In one embodiment of the formulation, the formulation is a paste containing at least one anthelmintic compound of formula (I), fumed silica, a viscosity modifier, an absorbent, a colorant; and a hydrophilic carrier which is triacetin, a monoglyceride, a diglyceride, or a triglyceride.

The paste may also include, but is not limited to, a viscosity modifier selected from the group consisting of PEG 200, PEG 300, PEG 400, PEG 600, monoethanolamine, triethanolamine, glycerol, propylene glycol, polyoxyethylene (20) sorbitan mono-oleate (POLYSORBATE 80 or TWEEN 80), and poloxomers (e.g., PLURONIC L 81); an absorbent selected from the group consisting of magnesium carbonate, calcium carbonate, starch, and cellulose and its derivatives; and a colorant selected from the group consisting of titanium dioxide iron oxide, and FD&C Blue #1 ALUMINUM LAKE.

The compositions may be in the form of a sterile injectable aqueous or oleagenous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butane diol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. Co-solvents such as ethanol, propylene glycol glycerol formal or polyethylene glycols may also be used. Preservatives, such as phenol or benzyl alcohol, may be used.

In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectable compositions.

Topical, dermal and subdermal formulations can include emulsions, creams, ointments, gels, pastes, powders, shampoos, pour-on formulations, ready-to-use formulations, spot-on solutions and suspensions, dips and sprays. Topical application of an inventive compound or of a composition including at least one inventive compound among active agent(s) therein, a spot-on or pour-on composition, can allow for the inventive compound to be absorbed through the skin to achieve systemic levels, distributed through the sebaceous glands or on the surface of the skin achieving levels throughout the hair coat. When the compound is distributed through the sebaceous glands, they can act as a reservoir, whereby there can be a long-lasting effect (up to several months) effect. Spot-on formulations are typically applied in a localized region which refers to an area other than the entire animal. In one embodiment of a localized region, the location is between the shoulders. In another embodiment of a localized region it is a stripe, e.g. a stripe from head to tail of the animal.

Pour-on formulations are described in U.S. Patent No. 6,010,710. The pour-on formulations may be advantageously oily, and generally comprise a diluent or vehicle and also a solvent (e.g. an organic solvent) for the active ingredient if the latter is not soluble in the diluent.

Organic solvents that can be used in the invention include but are not limited to: acetyltributyl citrate, fatty acid esters such as the dimethyl ester, acetone, acetonitrile, benzyl alcohol, butyl diglycol, dimethylacetamide, dimethylformamide, dipropylene glycol n-butyl ether, ethanol, isopropanol, methanol, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, monomethylacetamide, dipropylene glycol monomethyl ether, liquid polyoxyethylene glycols, propylene glycol, 2-pyrrolidone including N-methylpyrrolidone, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol, diisobutyl adipate, diisopropyl adipate (also known as CERAPHYL 230), triacetin, butyl acetate, octyl acetate, propylene carbonate, butylene carbonate, dimethylsulfoxide, organic amides including dimethylformamide and dimethylacetamide, and diethyl phthalate, or a mixture of at least two of these solvents.

In one embodiment of the invention, the pharmaceutically or veterinarily acceptable carrier of the formulation comprises C₁-C₁₀ alcohols or esters thereof (including acetates, such as ethyl acetate, butyl acetate and the like), C₁₀-C₁₈ saturated fatty acids or esters thereof, C₁₀-C₁₈ monounsaturated fatty acids or esters thereof, monoesters or diesters of aliphatic diacids, glycerol monoesters (e.g. monoglycerides), glycerol diesters (e.g. diglycerides), glycerol triesters (e.g. triglycerides such as triacetin), glycols, glycol ethers, glycol esters or glycol carbonates, polyethylene glycols of various grades (PEGs) or monoethers, diethers, monoesters or diesters thereof (e.g. diethylene glycol monoethyl ether), or mixtures thereof.

As vehicle or diluent, mention may be made of plant oils such as, but not limited to soybean oil, groundnut oil, castor oil, corn oil, cotton oil, olive oil, grape seed oil, sunflower oil, coconut oils etc.; mineral oils such as, but not limited to, petrolatum, paraffin, silicone, etc.; aliphatic or cyclic hydrocarbons or alternatively, for example, medium-chain (such as C8 to C12) triglycerides. In another embodiment of the invention, an emollient and/or spreading and/or film-forming agent can be added. One embodiment of the emollient and/or spreading and/or film-forming agent are those agents selected from the group consisting of:

1. (a) polyvinylpyrrolidone, polyvinyl alcohols, copolymers of vinyl acetate and vinylpyrrolidone, polyethylene glycols, benzyl alcohol, 2-pyrrolidones including, but not limited to N-methylpyrrolidone, mannitol, glycerol, sorbitol, polyoxyethylenated sorbitan esters; lecithin, sodium carboxymethylcellulose, silicone oils, polydiorganosiloxane oils (such as polydimethylsiloxane (PDMS) oils), for example those containing silanol functionalities, or a 45V2 oil,
2. (b) anionic surfactants such as alkaline stearates, sodium, potassium or ammonium stearates; calcium stearate, triethanolamine stearate; sodium abietate; alkyl sulfates (e.g. sodium lauryl sulfate and sodium cetyl sulfate); sodium dodecylbenzenesulfonate, sodium dioctylsulfosuccinate; fatty acids (e.g. those derived from coconut oil),
3. (c) cationic surfactants such as water-soluble quaternary ammonium salts of formula N⁺R'R"R"'R"", Y^- in which the radicals R are optionally hydroxylated hydrocarbon radicals and Y^- is an anion of a strong acid such as the halide, sulfate and sulfonate anions; cetyltrimethylammonium bromide is among the cationic surfactants which can be used,
4. (d) amine salts of formula N⁺ HR'R"R''' in which the radicals R, R', R" and R''' are optionally independently hydroxylated hydrocarbon radicals; octadecylamine hydrochloride is among the cationic surfactants which can be used,
5. (e) nonionic surfactants such as sorbitan esters, which are optionally polyoxyethylenated (e.g. POLYSORBATE 80), polyoxyethylenated alkyl ethers; polyoxypropylated fatty alcohols such as polyoxypropylene-styrol ether; polyethylene glycol stearate, polyoxyethylenated derivatives of castor oil, polyglycerol esters, polyoxyethylenated fatty alcohols, polyoxyethylenated fatty acids, copolymers of ethylene oxide and propylene oxide,
6. (f) amphoteric surfactants such as the substituted lauryl compounds of betaine; or
7. (g) a mixture of at least two of these agents.

The solvent will be used in proportion with the concentration of the anthelmintic compound of formula (I) and its solubility in this solvent. It will be sought to have the lowest possible volume. The vehicle makes up the difference to 100%.

In one embodiment of the amount of emollient, the emollient is used in a proportion of from 0.1 to 50% and 0.25 to 5%, by volume.

In another embodiment of the invention, the composition can be in ready-to-use solution form as is described in U.S. Patent No. 6,395,765. In addition to the anthelmintic compound of the invention, the ready-to-use solution can contain a crystallization inhibitor, an organic solvent and an organic co-solvent.

In one embodiment of the amount of crystallization inhibitor, the crystallization inhibitor can be present in a proportion of about 1 to about 30% (w/v) in the composition. In other embodiments, the crystallization inhibitor may be present in a proportion of about 1 to about 20% (w/v) and about 5 to about 15%. Acceptable inhibitors are those whose addition to the formulation inhibits the formation of crystals when the formulation is applied. In some embodiments, formulations may include compounds that function as crystallization inhibitors other than those listed herein. In these embodiments, the suitability of a crystallization inhibitor may be determined by a the test in which 0.3 ml of a solution comprising 10% (w/v) of an anthelmintic compound of the invention in the liquid carrier and 10% of the inhibitor are deposited on a glass slide at 20°C and allowed to stand for 24 hours. The slide is then observed with the naked eye. Acceptable inhibitors are those whose addition provides for few (e.g. less than ten crystals) or no crystal.

In one embodiment, the organic solvent has a dielectric constant of a range selected from the group consisting of between about 2 to about 35, about 10 to about 35 or about 20 to about 30. In other embodiments, the solvent will have a dielectric constant of between about 2 and about 20, or between about 2 and about 10. The content of this organic solvent in the overall composition represents the complement to 100% of the composition.

As discussed above, the solvent may comprise a mixture of solvents including a mixture of an organic solvent and an organic co-solvent. In one embodiment, and the organic co-solvent has a boiling point of less than about 300° C or less than about 250° C. In other embodiments, the co-solvent has a boiling point of below about 200° C., or below about 130° C. In still another embodiment of the invention, the organic co-solvent has a boiling point of below about 100° C., or below about 80° C. In still other embodiments, the organic co-solvent will have a dielectric constant of a range selected from the group consisting of about 2 to about 40, about 10 to about 40, or typically about 20 to about 30. In some embodiments of the invention, this co-solvent may be present in the composition in an organic co-solvent/organic solvent weight/weight (W/W) ratio of about 1/15 to about 1/2. In some embodiments, the co-solvent is volatile so as to act as a drying promoter, and is miscible with water and/or with the organic solvent.

The formulation can also comprise an antioxidizing agent intended to inhibit oxidation in air, this agent being present in a proportion selected from a range consisting of about 0.005 to about 1% (w/v) and about 0.01 to about 0.05%.

Crystallization inhibitors which are useful for the invention include but are not limited to:

1. (a) polyvinylpyrrolidone, polyvinyl alcohols, copolymers of vinyl acetate and of vinylpyrrolidone, polyethylene glycols of various grades, benzyl alcohol, 2-pyrrolidones including, but not limited to N-methylpyrrolidone, dimethylsulfoxide, mannitol, glycerol, sorbitol or polyoxyethylenated esters of sorbitan; lecithin or sodium carboxymethylcellulose; a solvent as described herein that is capable of inhibiting crystal formation; acrylic derivatives, such as acrylates and methacrylates or other polymers derived from acrylic monomers, and others;
2. (b) anionic surfactants, such as alkaline stearates (e.g. sodium, potassium or ammonium stearate); calcium stearate or triethanolamine stearate; sodium abietate; alkyl sulfates, which include but are not limited to sodium lauryl sulfate and sodium cetyl sulfate; sodium dodecylbenzenesulfonate or sodium dioctyl sulfosuccinate; or fatty acids (e.g. coconut oil);
3. (c) cationic surfactants, such as water-soluble quaternary ammonium salts of formula N⁺R'R"R'''R""Y^-, in which the R radicals are identical or different optionally hydroxylated hydrocarbon radicals and Y is an anion of a strong acid, such as halide, sulfate and sulfonate anions; cetyltrimethylammonium bromide is one of the cationic surfactants which can be used;
4. (d) amine salts of formula N⁺HR'R"R''', in which the R radicals are identical or different optionally hydroxylated hydrocarbon radicals; octadecylamine hydrochloride is one of the cationic surfactants which can be used;
5. (e) non-ionic surfactants, such as optionally polyoxyethylenated esters of sorbitan, e.g. POLYSORBATE 80, or polyoxyethylenated alkyl ethers; polyethylene glycol stearate, polyoxyethylenated derivatives of castor oil, polyglycerol esters, polyoxyethylenated fatty alcohols, polyoxyethylenated fatty acids or copolymers of ethylene oxide and of propylene oxide;
6. (f) amphoteric surfactants, such as substituted lauryl compounds of betaine; or
7. (g) a mixture of at least two of the compounds listed in (a)-(f) above.

In one embodiment of the film-forming agent, the agents are of the polymeric type which include but are not limited to the various grades of polyvinylpyrrolidone, polyvinyl alcohols, and copolymers of vinyl acetate and of vinylpyrrolidone.

In one embodiment of the surface-active agents, the agents include but are not limited to those made of non-ionic surfactants; in another embodiment of the surface active agents, the agent is a polyoxyethylenated esters of sorbitan and in yet another embodiment of the surface-active agent, the agents include the various grades of POLYSORBATE, for example POLYSORBATE 80.

In another embodiment of the invention, the film-forming agent and the surface-active agent can be incorporated in similar or identical amounts within the limit of the total amounts of crystallization inhibitor mentioned elsewhere.

The pair thus constituted secures, in a noteworthy way, the objectives of absence of crystallization on the coat and of maintenance of the cosmetic appearance of the skin or fur, that is to say without a tendency towards sticking or towards a sticky appearance, despite the high concentration of active material.

In one embodiment of the antioxidizing agents, the agents are those conventional in the art and include but is not limited to butylated hydroxyanisole, butylated hydroxytoluene, ascorbic acid, sodium metabisulphite, propyl gallate, sodium thiosulfate or a mixture of not more than two of them.

The formulation adjuvants discussed above are well known to the practitioner in this art and may be obtained commercially or through known techniques. These concentrated compositions are generally prepared by simple mixing of the constituents as defined above; advantageously, the starting point is to mix the active material in the main solvent and then the other ingredients or adjuvants are added.

The volume applied is not restricted as long as the amount of substance administered is shown to be safe and efficacious. Typically, the volume applied depends on the size and weight of the animal as well as the concentration of active, the extent of infestation by parasites and the type of administration. In some embodiments, the volume applied can be of the order of about 0.3 to about 5 ml or about 0.3 ml to about 1 ml. In one embodiment for the volume, the volume is on the order of about 0.5 ml, for cats and on the order of about 0.3 to about 3 ml for dogs, depending on the weight of the animal.

In another embodiment of the invention, application of a spot-on formulation according to the present invention can also provide long-lasting and broad-spectrum efficacy when the solution is applied to the mammal or bird. The spot-on formulations provide for topical administration of a concentrated solution, suspension, microemulsion or emulsion for intermittent application to a spot on the animal, generally between the two shoulders (solution of spot-on type).

For spot-on formulations, the carrier can be a liquid carrier vehicle as described in U.S. Patent No. 6,426,333, which in one embodiment of the spot-on formulation comprises a solvent and a co-solvent wherein the solvent is selected from the group consisting of acetone, acetonitrile, benzyl alcohol, butyl diglycol, dimethylacetamide, dimethylformamide, dipropylene glycol n-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diisobutyl adipate, diisopropyl adipate (also known as CERAPHYL 230), triacetin, butyl acetate, octyl acetate, propylene carbonate, butylene carbonate, dimethylsulfoxide, organic amides including dimethylformamide and dimethylacetamide, ethanol, isopropanol, methanol, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, monomethylacetamide, dipropylene glycol monomethyl ether, liquid polyoxyethylene glycols, propylene glycol, 2-pyrrolidone including N-methylpyrrolidone, diethylene glycol monoethyl ether, ethylene glycol, diethyl phthalate fatty acid esters, such as the diethyl ester or diisobutyl adipate, and a mixture of at least two of these solvents and the co-solvent is selected from the group consisting of absolute ethanol, isopropanol or methanol.

In one embodiment of the invention, the pharmaceutically or veterinarily acceptable carrier of the formulation comprises C₁-C₁₀ alcohols or esters thereof (including acetates, such as ethyl acetate, butyl acetate and the like), C₁₀-C₁₈ saturated fatty acids or esters thereof, C₁₀-C₁₈ monounsaturated fatty acids or esters thereof, monoesters or diesters of aliphatic diacids, glycerol monoesters (e.g. monoglycerides), glycerol diesters (e.g. diglycerides), glycerol triesters (e.g. triglycerides such as triacetin), glycols, glycol ethers, glycol esters or glycol carbonates, polyethylene glycols of various grades (PEGs) or monoethers, diethers, monoesters or diesters thereof (e.g. diethylene glycol monoethyl ether), or mixtures thereof.

The liquid carrier vehicle can optionally contain a crystallization inhibitor including an anionic surfactant, a cationic surfactant, a non-ionic surfactant, an amine salt, an amphoteric surfactant or polyvinylpyrrolidone, polyvinyl alcohols, copolymers of vinyl acetate and vinylpyrrolidone, 2-pyrrolidone including N-methylpyrrolidone (NMP), dimethylsulfoxide, polyethylene glycols, benzyl alcohol, mannitol, glycerol, sorbitol, polyoxyethylenated sorbitan esters; lecithin, sodium carboxymethylcellulose, solvents as defined herein that can inhibit the formation of crystals, and acrylic derivatives such acrylates or methacrylates as well as other polymers derived from acrylic monomers, or a mixture of these crystallization inhibitors.

Spot-on formulations may be prepared by dissolving the active ingredients into the pharmaceutically or veterinary acceptable vehicle. Alternatively, the spot-on formulation can be prepared by encapsulation of the active ingredient to leave a residue of the therapeutic agent on the surface of the animal. These formulations will vary with regard to the weight of the therapeutic agent in the combination depending on the species of host animal to be treated, the severity and type of infection and the body weight of the host.

Dosage forms may contain from about 0.5 mg to about 5 g of an active agent. In one embodiment of the dosage form, the dosage is from about 1 mg to about 500 mg of an active agent, typically about 25 mg, about 50 mg, about 100 mg, about 200 mg, about 300 mg, about 400 mg, about 500 mg, about 600 mg, about 800 mg, or about 1000 mg.

In one embodiment of the invention, the active agent is present in the formulation at a concentration of about 0.05% to about 50% weight/volume. In other embodiments, the active agent may be present in the formulation at a concentration of about 0.1% to about 30%, about 0.5% to about 20% (w/v) or about 1% to about 10% (w/v). In another embodiment of the invention, the active agent is present in the formulation as a concentration from about 0.1 to 2% weight/volume. In yet another embodiment of the invention, the active agent is present in the formulation as a concentration from about 0.25 to about 1.5% weight/volume. In still another embodiment of the invention, the active agent is present in the formulation as a concentration about 1% weight/volume.

In a particular advantageous embodiment of the invention, the dose of the inventive compounds is about 0.1 mg/kg to about 100 mg/kg. In other embodiments, the dose of the inventive compounds is about 0.5 mg/kg to about 70 mg/kg, about 0.5 mg/kg to about 50 mg/kg or about 0.5 mg/kg to about 30 mg/kg. In other preferred embodiments, the dose is 0.5 mg/kg to about 30 mg/kg, 0.5 mg/kg to about 20 mg/kg or 0.5 mg/kg to about 10 mg/kg. More typically, in some embodiments the dose of the active compounds is about 0.1 mg/kg to 5 mg/kg, 0.1 mg/kg to about 3 mg/kg, or about 0.1 mg/kg to 1.5 mg/kg. In still other embodiments of the invention, the dose may be as low as 0.1 mg/kg (0.02 mg/ml), about 0.2 mg/kg (0.04 mg/ml), about 0.3 mg/kg (0.06 mg/ml), about 0.4 mg/kg (0.08 mg/ml), about 0.5 mg/kg (0.1 mg/ml), about 0.6 mg/kg (0.12 mg/ml), about 0.7 mg/kg (0.14 mg/ml), about 0.8 8 mg/kg (0.16 mg/ml), about 0.9 mg/kg (0.18 mg/ml), about 1.0 mg/kg (0.2 mg/ml).

Another embodiment of the invention is directed toward a method of treating endoparasitic infestation or infection in an animal, comprising administering an effective amount of the compound of the invention to the animal in need thereof. The compounds of the invention have been shown to have superior efficacy against endoparasites, and in particular against parasites that are resistant to active agents of the macrocyclic lactone class. For example, a compound of the invention has been shown to have superior efficacy against ivermectin-resistant endoparasites in sheep. Figure 2 shows that a compound of the invention (compound 3.024) administered at a dosage of 1.5 mg/kg or 3 mg/kg orally had greater than 95% efficacy against ivermectin-resistant strains of Haemonchus contortus, Ostertagia circumcincta and Trichostrongylus columbriformis. In contrast, ivermectin administered orally at a dose of 0.2 mg/kg was almost completely inactive against Haemonchus contortus, less than 30% effective against Ostertagia circumcincta and less than 60% effective against Trichostrongylus columbriformis. It is surprising that the compounds of the invention have superior efficacy against endoparasites that are resistant to ivermectin, which is one of the most potent active agents known against endo- and ectoparasites.

Accordingly, in another embodiment, the invention provides a method for treating an endoparasitic infestation or infection in an animal, comprising administering an effective amount of an anthelmintic compound of the invention in combination with an effective amount of activators of invertebrate GABA receptors including an avermectin or milbemycin to the animal in need thereof. Avermectins that may be used in combination with the compounds of the invention include, but are not limited to abamectin, dimadectin, doramectin, emamectin, eprinomectin, ivermectin, latidectin, lepimectin, and selamectin Milbemycins compounds that may be used in combination with the compounds of the invention include, but are not limited to, milbemectin, milbemycin D, moxidectin and nemadectin. Also included are the 5-oxo and 5-oxime derivatives of said avermectins and milbemycins.

In one embodiment, the compounds and compositions of the invention may be used for treating endoparasiticidal infection or infestation an endoparasite including, but not limited to, Anaplocephala (Anoplocephala), Ancylostoma, Anecator, Ascaris, Brugia, Bunostomum, Capillaria, Chabertia, Cooperia, Cyathostomum, Cylicocyclus, Cylicodontophorus, Cylicostephanus, Craterostomum, Dictyocaulus, Dipetalonema, Dipylidium, Dirofilaria, Dracunculus, Echinococcus, Enterobius, Fasciola, Filaroides, Habronema, Haemonchus, Metastrongylus, Moniezia, Necator, Nematodirus, Nippostrongylus, Oesophagostumum, Onchocerca, Ostertagia, Oxyuris, Parascaris, Schistosoma, Strongylus, Taenia, Toxocara, Strongyloides, Toxascaris, Trichinella, Trichuris, Trichostrongylus, Triodontophorus, Uncinaria, Wuchereria, and combinations thereof.

In a particularly preferred embodiment of the invention, the compounds and compositions of the invention are used to treat or prevent an infection by Dirofilaria immitis. In another embodiment the compounds and compositions of the invention are used to treat or prevent an infection by Dirofilaria repens.

In another embodiment of the invention, the helminth is Haemonchus contortus, Ostertagia circumcincta, Trichostrongylus axei, Trichostrongylus colubriformis, Cooperia curticei, Nematodirus battus and combinations thereof.

Another embodiment of the invention is directed toward a method of treating ectoparasitic infestation or infection in an animal in need thereof which comprises administering an effective amount of the compound of the invention to the animal in need thereof.

In one embodiment, the infection or infestation is caused by fleas, ticks, mites, mosquitoes, flies, lice, blowfly and combinations thereof.

In still another embodiment, invention provides a method for treating an ectoparasitic infestation or infection in an animal, comprising administering an effective amount of an anthelmintic compound of the invention in combination with an effective amount of an avermectin or milbemycin active agent to the animal in need thereof.

In certain embodiments, the compounds of the invention may be used to protect plants and crops. In other embodiments, the compounds may be used to treat environmental surfaces and structures.

The compounds of formula (I) or their salts can be employed as such or in the form of their preparations (formulations) as combinations with other active substances, such as, for example, insecticides, attractants, sterilants, acaricides, nematicides, and with growth regulators.

Bactericides include, but are not limited to, bronopol, dichlorophen, nitrapyrin, nickel dimethyldithiocarbamate, kasugamycin, octhilinone, furancarboxylic acid, oxytetracycline, probenazole, streptomycin, tecloftalam, copper sulphate and other copper preparations.

Insecticides/acaricides/nematicides include those compounds mentioned in U.S. Patent Nos. 7,420,062 and 7,001,903, U.S. Patent publication 2008/0234331, the literature known to the person skilled in the art, and the compounds classified by IRAC (Insecticide Resistance Action Committee). Examples of insecticides/acaricides/nematicides include, but are limited to, carbamates; triazemate; organophosphates; cyclodiene organochlorines; phenylpyrazoles; DDT; methoxychlor; pyrethroids; pyrethrins; neonicotinoids; nicotine; bensultap; cartap hydrochloride; nereistoxin analogues; spinosyns; avermectins and milbemycins; juvenile hormone analogues; fenoxycarb; fenoxycarb; alkyl halides; chloropicrin; sulfuryl fluoride; cryolite; pymetrozine; flonicamid; clofentezine; hexythiazox; etoxazole; Bacillus sphaericus; diafenthiuron; organotin miticides; propargite; tetradifon; chlorfenapyr; DNOC; benzoylureas; buprofezin; cyromazine; diacylhydrazines; azadirachtin; amitraz; hydramethylnon; acequinocyl; fluacrypyrim; METI acaricides; rotenone; indoxacarb; metaflumizone; tetronic acid derivatives; aluminium phosphide; cyanide; phosphine; bifenazate; fluoroacetate; P450-dependent monooxygenase inhibitors; esterase inhibitors; diamides; benzoximate; chinomethionat; dicofol; pyridalyl; borax; tartar emetic; fumigants, such as methyl bromide; ditera; clandosan; sincocin.

The compounds of formula (I) can be formulated in various ways, depending on the prevailing biological and/or chemico-physical parameters. Examples of possible formulations which are suitable are: wettable powders (WP), water-soluble powders (SP), water-soluble concentrates, emulsifiable concentrates (EC), emulsions (EW) such as oil-in-water and water-in-oil emulsions, sprayable solutions, suspension concentrates (SC), dispersions on an oil or water basis, solutions which are miscible with oil, capsule suspensions (CS), dusts (DP), seed-dressing products, granules for broadcasting and soil application, granules (GR) in the form of microgranules, spray granules, coated granules and adsorption granules, water-dispersible granules (WG), water-soluble granules (SG), ULV formulations, microcapsules and waxes.

Solid state forms of the compounds of formula (I) can be prepared by methods known in the art, e.g. Byrn et al., "Solid-State Chemistry of Drugs", 2^nd Edition, SSCI Inc., (1999); Glusker et al., "Crystal Structure Analysis - A Primer", 2^nd Edition, Oxford University Press, (1985).

The formulations mentioned can be prepared in a manner known per se, for example by mixing the active compounds with at least one solvent or diluent, emulsifier, dispersant and/or binder or fixative, water repellent and optionally one or more of a desiccant, UV stabilizer, a colorant, a pigment and other processing auxiliaries.

These individual formulation types are known in principle and described, for example, in: Winnacker-Küchler, "Chemische Technologie" [Chemical Technology], Volume 7, C. Hauser Verlag, Munich, 4th Edition 1986; Wade van Valkenburg, "Pesticide Formulations", Marcel Dekker, N.Y., 1973; K. Martens, "Spray Drying Handbook", 3rd Ed. 1979, G. Goodwin Ltd. London.

The necessary formulation auxiliaries such as inert materials, surfactants, solvents and other additives are also known and described, for example, in: Watkins, "Handbook of Insecticide Dust Diluents and Carriers", 2nd Ed., Darland Books, Caldwell N.J.; H.v. Olphen, "Introduction to Clay Colloid Chemistry", 2nd Ed., J. Wiley & Sons, N.Y.; C. Marsden, "Solvents Guide", 2nd Ed., Interscience, N.Y. 1963; McCutcheon's "Detergents and Emulsifiers Annual", MC Publ. Corp., Ridgewood N.J.; Sisley and Wood, "Encyclopedia of Surface Active Agents", Chem. Publ. Co. Inc., N.Y. 1964; Schönfeldt, "Grenzflächenaktive Äthylenoxidaddukte" [Surface-active ethylene oxide adducts], Wiss. Verlagsgesell., Stuttgart 1976; Winnacker-Küchler, "Chemische Technologie" [Chemical Technology], Volume 7, C. Hauser Verlag, Munich, 4th Ed. 1986.

Wettable powders are preparations which are uniformly dispersible in water and which, besides the compounds of formula (I), also comprise ionic and/or nonionic surfactants (wetters, dispersants), for example, polyoxyethylated alkylphenols, polyoxyethylated fatty alcohols, polyoxyethylated fatty amines, fatty alcohol polyglycol ether sulfates, alkanesulfonates or alkylbenzenesulfonates, sodium lignosulfonate, sodium 2,2'-dinaphthylmethane-6,6'-disulfonate, sodium dibutylnaphthalenesulfonate or else sodium oleoylmethyltaurinate, in addition to a diluent or inert substance. To prepare the wettable powders, the compounds of formula (I) are, for example, ground finely in conventional apparatuses such as hammer mills, blower mills and air-jet mills and mixed with the formulation auxiliaries, either concomitantly or thereafter.

Emulsifiable concentrates are prepared, for example, by dissolving the compounds of formula (I) in an organic solvent, for example butanol, cyclohexanone, dimethylformamide, xylene or else higher-boiling aromatics or hydrocarbons or mixtures of these, with addition of one or more ionic and/or nonionic surfactants (emulsifiers). Emulsifiers which can be used are, for example: calcium salts of alkylarylsulfonic acids, such as calcium dodecylbenzenesulfonate or nonionic emulsifiers, such as fatty acid polyglycol esters, alkylaryl polyglycol ethers, fatty alcohol polyglycol ethers, propylene oxide/ethylene oxide condensates, alkyl polyethers, sorbitan esters such as sorbitan fatty acid esters or polyoxyethylene sorbitan esters such as polyoxyethylene sorbitan fatty acid esters.

Dusts are obtained by grinding the active substance with finely divided solid substances, for example talc or natural clays, such as kaolin, bentonite or pyrophyllite, or diatomaceous earth.

Suspension concentrates may be water- or oil-based. They can be prepared, for example, by wet grinding by means of commercially available bead mills, if appropriate with addition of surfactants, as they have already been mentioned above for example in the case of the other formulation types.

Emulsions, for example oil-in-water emulsions (EW), can be prepared for example by means of stirrers, colloid mills and/or static mixtures using aqueous organic solvents and, if appropriate, surfactants as they have already been mentioned above for example in the case of the other formulation types.

Granules can be prepared either by spraying the compounds of formula (I) onto adsorptive, granulated inert material or by applying active substance concentrates onto the surface of carriers such as sand, kaolinites or of granulated inert material, by means of binders, for example polyvinyl alcohol, sodium polyacrylate or alternatively mineral oils. Suitable active substances can also be granulated in the manner which is conventional for the production of fertilizer granules, if desired in a mixture with fertilizers.

Water-dispersible granules are prepared, as a rule, by the customary processes such as spray-drying, fluidized-bed granulation, disk granulation, mixing in high-speed mixers and extrusion without solid inert material. To prepare disk, fluidized-bed, extruder and spray granules, see, for example, processes in "Spray-Drying Handbook" 3rd ed. 1979, G. Goodwin Ltd., London; J.E. Browning, "Agglomeration", Chemical and Engineering 1967, pages 147 et seq.; "Perry's Chemical Engineer's Handbook", 5th Ed., McGraw-Hill, New York 1973, p. 8-57. In general, the agrochemical preparations comprise a range selected from the group consisting of about 0.1 to about 99% by weight and about 0.1 to about 95% by weight, of compounds of formula (I).

The concentration of compounds of formula (I) in wettable powders is, for example, about 10 to about 90% by weight, the remainder to 100% by weight being composed of customary formulation components. In the case of emulsifiable concentrates, the concentration of compounds of formula (I) can amount to ranges selected from the group consisting of about 1% to about 90% and about 5% to about 80% by weight. Formulations in the form of dusts usually comprise in the range selected from the group consisting of about 1% to about 30% by weight of compounds of formula (I) and about 5% to about 20% by weight of compounds of formula (I). For sprayable solutions comprise a range selected from the group consisting of about 0.05% to about 80% by weight of compounds of formula (I) and about 2% to about 50% by weight of compounds of formula (I). In the case of water-dispersible granules, the content of compounds of formula (I) depends partly on whether the compounds of formula (I) are in liquid or solid form and on which granulation auxiliaries, fillers and the like are being used. The water-dispersible granules, for example, comprise a range selected from the group consisting of between about 1 and about 95% and between about 10% and about 80% by weight.

In addition, the formulations of compounds of formula (I) mentioned comprise, if appropriate, the adhesives, wetters, dispersants, emulsifiers, penetrants, preservatives, antifreeze agents, solvents, fillers, carriers, colorants, antifoams, evaporation inhibitors, pH regulators and viscosity regulators which are conventional in each case.

Additional pharmaceutically or veterinarily active ingredients may also be added to the compositions of the invention. In some embodiments, the additional active agents may be one or more parasiticidal compounds including acaricides, anthelmintics, endectocides and insecticides. Anti-parasitic agents can include both ectoparasiticisal and endoparasiticidal agents.

Additional pharmaceutical agents that may be included in the compositions of the invention with the inventive anthelmintic compounds are well-known in the art (see e.g. Plumb' Veterinary Drug Handbook, 5th Edition, ed. Donald C. Plumb, Blackwell Publishing, (2005) or The Merck Veterinary Manual, 9th Edition, (January 2005)) and include but are not limited to acarbose, acepromazine maleate, acetaminophen, acetazolamide, acetazolamide sodium, acetic acid, acetohydroxamic acid, acetylcysteine, acitretin, acyclovir, albendazole, albuterol sulfate, alfentanil, allopurinol, alprazolam, altrenogest, amantadine, amikacin sulfate, aminocaproic acid, aminopentamide hydrogen sulfate, aminophylline/theophylline, amiodarone, amitriptyline, amlodipine besylate, ammonium chloride, ammonium molybdenate, amoxicillin, clavulanate potassium, amphotericin B desoxycholate, amphotericin B lipid-based, ampicillin, amprolium, antacids (oral), antivenin, apomorphione, apramycin sulfate, ascorbic acid, asparaginase, aspiring, atenolol, atipamezole, atracurium besylate, atropine sulfate, aurnofin, aurothioglucose, azaperone, azathioprine, azithromycin, baclofen, barbituates, benazepril, betamethasone, bethanechol chloride, bisacodyl, bismuth subsalicylate, bleomycin sulfate, boldenone undecylenate, bromides, bromocriptine mesylate, budenoside, buprenorphine, buspirone, busulfan, butorphanol tartrate, cabergoline, calcitonin salmon, calcitrol, calcium salts, captopril, carbenicillin indanyl sodium, carbimazole, carboplatin, carnitine, carprofen, carvedilol, cefadroxil, cefazolin sodium, cefixime, clorsulon, cefoperazone sodium, cefotaxime sodium, cefotetan disodium, cefoxitin sodium, cefpodoxime proxetil, ceftazidime, ceftiofur sodium, ceftiofur, ceftiaxone sodium, cephalexin, cephalosporins, cephapirin, charcoal (activated), chlorambucil, chloramphenicol, chlordiazepoxide, chlordiazepoxide +/- clidinium bromide, chlorothiazide, chlorpheniramine maleate, chlorpromazine, chlorpropamide, chlortetracycline, chorionic gonadotropin (HCG), chromium, cimetidine, ciprofloxacin, cisapride, cisplatin, citrate salts, clarithromycin, clemastine fumarate, clenbuterol, clindamycin, clofazimine, clomipramine, claonazepam, clonidine, cloprostenol sodium, clorazepate dipotassium, clorsulon, cloxacillin, codeine phosphate, colchicine, corticotropin (ACTH), cosyntropin, cyclophosphamide, cyclosporine, cyproheptadine, cytarabine, dacarbazine, dactinomycin/actinomycin D, dalteparin sodium, danazol, dantrolene sodium, dapsone, decoquinate, deferoxamine mesylate, deracoxib, deslorelin acetate, desmopressin acetate, desoxycorticosterone pivalate, detomidine, dexamethasone, dexpanthenol, dexraazoxane, dextran, diazepam, diazoxide (oral), dichlorphenamide, diclofenac sodium, dicloxacillin, diethylcarbamazine citrate, diethylstilbestrol (DES), difloxacin, digoxin, dihydrotachysterol (DHT), diltiazem, dimenhydrinate, dimercaprol/BAL, dimethyl sulfoxide, dinoprost tromethamine, diphenylhydramine, disopyramide phosphate, dobutamine, docusate/DSS, dolasetron mesylate, domperidone, dopamine, doramectin, doxapram, doxepin, doxorubicin, doxycycline, edetate calcium disodium.calcium EDTA, edrophonium chloride, enalapril/enalaprilat, enoxaparin sodium, enrofloxacin, ephedrine sulfate, epinephrine, epoetin/erythropoietin, eprinomectin, epsiprantel, erythromycin, esmolol, estradiol cypionate, ethacrynic acid/ethacrynate sodium, ethanol (alcohol), etidronate sodium, etodolac, etomidate, euthanasia agents w/pentobarbital, famotidine, fatty acids (essential/omega), felbamate, fentanyl, ferrous sulfate, filgrastim, finasteride, fipronil, florfenicol, fluconazole, flucytosine, fludrocortisone acetate, flumazenil, flumethasone, flunixin meglumine, fluorouracil (5-FU), fluoxetine, fluticasone propionate, fluvoxamine maleate, fomepizole (4-MP), furazolidone, furosemide, gabapentin, gemcitabine, gentamicin sulfate, glimepiride, glipizide, glucagon, glucocorticoid agents, glucosamine/chondroitin sulfate, glutamine, glyburide, glycerine (oral), glycopyrrolate, gonadorelin, grisseofulvin, guaifenesin, halothane, hemoglobin glutamer-200 (OXYGLOBIN®®), heparin, hetastarch, hyaluronate sodium, hydrazaline, hydrochlorothiazide, hydrocodone bitartrate, hydrocortisone, hydromorphone, hydroxyurea, hydroxyzine, ifosfamide, imidacloprid, imidocarb dipropinate, impenem-cilastatin sodium, imipramine, inamrinone lactate, insulin, interferon alfa-2a (human recombinant), iodide (sodium/potassium), ipecac (syrup), ipodate sodium, iron dextran, isoflurane, isoproterenol, isotretinoin, isoxsuprine, itraconazole, ivermectin, kaolin/pectin, ketamine, ketoconazole, ketoprofen, ketorolac tromethamine, lactulose, leuprolide, levamisole, levetiracetam, levothyroxine sodium, lidocaine, lincomycin, liothyronine sodium, lisinopril, lomustine (CCNU), lufenuron, lysine, magnesium, mannitol, marbofloxacin, mechlorethamine, meclizine, meclofenamic acid, medetomidine, medium chain triglycerides, medroxyprogesterone acetate, megestrol acetate, melarsomine, melatonin, meloxican, melphalan, meperidine, mercaptopurine, meropenem, metformin, methadone, methazolamide, methenamine mandelate/hippurate, methimazole, methionine, methocarbamol, methohexital sodium, methotrexate, methoxyflurane, methylene blue, methylphenidate, methylprednisolone, metoclopramide, metoprolol, metronidaxole, mexiletine, mibolerlone, midazolam milbemycin oxime, mineral oil, minocycline, misoprostol, mitotane, mitoxantrone, morphine sulfate, moxidectin, naloxone, mandrolone decanoate, naproxen, narcotic (opiate) agonist analgesics, neomycin sulfate, neostigmine, niacinamide, nitazoxanide, nitenpyram, nitrofurantoin, nitroglycerin, nitroprusside sodium, nizatidine, novobiocin sodium, nystatin, octreotide acetate, olsalazine sodium, omeprozole, ondansetron, opiate antidiarrheals, orbifloxacin, oxacillin sodium, oxazepam, oxibutynin chloride, oxymorphone, oxytretracycline, oxytocin, pamidronate disodium, pancreplipase, pancuronium bromide, paromomycin sulfate, parozetine, pencillamine, general information penicillins, penicillin G, penicillin V potassium, pentazocine, pentobarbital sodium, pentosan polysulfate sodium, pentoxifylline, pergolide mesylate, phenobarbital, phenoxybenzamine, pheylbutazone, phenylephrine, phenypropanolamine, phenytoin sodium, pheromones, parenteral phosphate, phytonadione/vitamin K-1, pimobendan, piperazine, pirlimycin, piroxicam, polysulfated glycosaminoglycan, ponazuril, potassium chloride, pralidoxime chloride, prazosin, prednisolone/prednisone, primidone, procainamide, procarbazine, prochlorperazine, propantheline bromide, propionibacterium acnes injection, propofol, propranolol, protamine sulfate, pseudoephedrine, psyllium hydrophilic mucilloid, pyridostigmine bromide, pyrilamine maleate, pyrimethamine, quinacrine, quinidine, ranitidine, rifampin, s-adenosyl-methionine (SAMe), saline/hyperosmotic laxative, selamectin, selegiline /1-deprenyl, sertraline, sevelamer, sevoflurane, silymarin/milk thistle, sodium bicarbonate, sodium polystyrene sulfonate, sodium stibogluconate, sodium sulfate, sodum thiosulfate, somatotropin, sotalol, spectinomycin, spironolactone, stanozolol, streptokinase, streptozocin, succimer, succinylcholine chloride, sucralfate, sufentanil citrate, sulfachlorpyridazine sodium, sulfadiazine/trimethroprim, sulfamethoxazole/trimethoprim, sulfadimentoxine, sulfadimethoxine/ormetoprim, sulfasalazine, taurine, tepoxaline, terbinafline, terbutaline sulfate, testosterone, tetracycline, thiacetarsamide sodium, thiamine, thioguanine, thiopental sodium, thiotepa, thyrotropin, tiamulin, ticarcilin disodium, tiletamine /zolazepam, tilmocsin, tiopronin, tobramycin sulfate, tocainide, tolazoline, telfenamic acid, topiramate, tramadol, trimcinolone acetonide, trientine, trilostane, trimepraxine tartrate w/prednisolone, tripelennamine, tylosin, urdosiol, valproic acid, vanadium, vancomycin, vasopressin, vecuronium bromide, verapamil, vinblastine sulfate, vincristine sulfate, vitamin E/selenium, warfarin sodium, xylazine, yohimbine, zafirlukast, zidovudine (AZT), zinc acetate/zinc sulfate, zonisamide and mixtures thereof.

In one embodiment of the invention, arylpyrazole compounds such as phenylpyrazoles, known in the art may be combined with the anthelmintic compounds of the invention. Examples of such arylpyrazole compounds include but are not limited to those described in U.S. Patent Nos. 6,001,384; 6,010,710; 6,083,519; 6,096,329; 6,174,540; 6,685,954 and 6,998,131. On particularly preferred arylpyrazole compound is fipronil.

In another embodiment of the invention, one or more macrocyclic lactones or lactams, which act as an acaricide, anthelmintic agent and/or insecticide, can be added to the compositions of the invention.

The macrocyclic lactones include, but are not limited to, avermectins such as abamectin, dimadectin, doramectin, emamectin, eprinomectin, ivermectin, latidectin, lepimectin, selamectin and ML-1,694,554, and milbemycins such as milbemectin, milbemycin D, moxidectin and nemadectin. Also included are the 5-oxo and 5-oxime derivatives of said avermectins and milbemycins. Examples of combinations of arylpyrazole compounds with macrocyclic lactones include but are not limited to those described in U.S. Patent Nos. 6,426,333; 6,482,425; 6,962,713 and 6,998,131.

The macrocyclic lactone compounds are known in the art and can easily be obtained commercially or through synthesis techniques known in the art. Reference is made to the widely available technical and commercial literature. For avermectins, ivermectin and abamectin, reference may be made, for example, to the work "Ivermectin and Abamectin", 1989, by M.H. Fischer and H. Mrozik, William C. Campbell, published by Springer Verlag., or Albers-Schönberg et al. (1981), "Avermectins Structure Determination", J. Am. Chem. Soc., 103, 4216-4221. For doramectin, "Veterinary Parasitology", vol. 49, No. 1, July 1993, 5-15 may be consulted. For milbemycins, reference may be made, inter alia, to Davies H.G. et al., 1986, "Avermectins and Milbemycins", Nat. Prod. Rep., 3, 87-121, Mrozik H. et al., 1983, Synthesis of Milbemycins from Avermectins, Tetrahedron Lett., 24, 5333-5336, U.S. Patent No. 4,134,973 and EP 0 677 054.

Macrocyclic lactones are either natural products or are semi-synthetic derivatives thereof. The structure of the avermectins and milbemycins are closely related, e.g., by sharing a complex 16-membered macrocyclic lactone ring. The natural product avermectins are disclosed in U.S. Patent No. 4,310,519 and the 22,23-dihydro avermectin compounds are disclosed in U.S. Patent No. 4,199,569. Mention is also made of U.S. Patent Nos. 4,468,390, 5,824,653, EP 0 007 812 A1, U.K. Patent Specification 1 390 336, EP 0 002 916, and New Zealand Patent No. 237 086, inter alia. Naturally occurring milbemycins are described in U.S. Patent No. 3,950,360 as well as in the various references cited in "The Merck Index" 12th ed., S. Budavari, Ed., Merck & Co., Inc. Whitehouse Station, New Jersey (1996). Latidectin is described in the "International Nonproprietary Names for Pharmaceutical Substances (INN)", WHO Drug Information, vol. 17, no. 4, pp. 263- 286, (2003). Semisynthetic derivatives of these classes of compounds are well known in the art and are described, for example, in U.S. Patent Nos. 5,077,308, 4,859,657, 4,963,582, 4,855,317, 4,871,719, 4,874,749, 4,427,663, 4,310,519, 4,199,569, 5,055,596, 4,973,711, 4,978,677, 4,920,148 and EP 0 667 054.

In another embodiment of the invention, the compositions may include a class of acaricides or insecticides known as insect growth regulators (IGRs). Compounds belonging to this group are well known to the practitioner and represent a wide range of different chemical classes. These compounds all act by interfering with the development or growth of the insect pests. Insect growth regulators are described, for example, in U.S. Patent Nos. 3,748,356, 3,818,047, 4,225,598, 4,798,837, 4,751,225, EP 0 179 022 or U.K. 2 140 010 as well as U.S. Patent Nos. 6,096,329 and 6,685,954.

In one embodiment the IGR that may be included in the composition is a compound that mimics juvenile hormone. Examples of juvenile hormone mimics include azadirachtin, diofenolan, fenoxycarb, hydroprene, kinoprene, methoprene, pyriproxyfen, tetrahydroazadirachtin and 4-chloro-2(2-chloro-2-methyl-propyl)-5-(6-iodo-3-pyridylmethoxy)pyridazine-3(2H)-one. In a particularly preferred embodiment, the compositions of the invention comprise methoprene or pyriproxyfen.

In another embodiment, the compositions of the invention may include an IGR compound that is a chitin synthesis inhibitor. Chitin synthesis inhibitors include chlorofluazuron, cyromazine, diflubenzuron, fluazuron, flucycloxuron, flufenoxuron, hexaflumoron, lufenuron, tebufenozide, teflubenzuron, triflumoron, novaluron, 1-(2,6-difluorobenzoyl)-3-(2-fluoro-4-(trifluoromethyl)phenylurea, 1-(2,6-difluoro-benzoyl)-3-(2-fluoro-4-(1,1,2,2-tetrafluoroethoxy)-phenylurea and 1-(2,6-difluorobenzoyl)-3-(2-fluoro-4-trifluoromethyl)phenylurea.

In yet another embodiment of the invention, adulticide insecticides and acaricides can also be added to the composition of the invention. These include pyrethrins (which include cinerin I, cinerin II, jasmolin I, jasmolin II, pyrethrin I, pyrethrin II and mixtures thereof) and pyrethroids, and carbamates including, but are not limited to, benomyl, carbanolate, carbaryl, carbofuran, meththiocarb, metolcarb, promacyl, propoxur, aldicarb, butocarboxim, oxamyl, thiocarboxime and thiofanox.

In some embodiments, the compositions of the invention may include one or more antinematodal agents including, but not limited to, active agents in the benzimidazoles, imidazothiazoles, tetrahydropyrimidines, and organophosphate class of compounds. In some embodiments, benzimidazoles including, but not limited to, thiabendazole, cambendazole, parbendazole, oxibendazole, mebendazole, flubendazole, fenbendazole, oxfendazole, albendazole, cyclobendazole, febantel, thiophanate and its o,o-dimethyl analogue may be included in the compositions.

In other embodiments, the compositions may include an imidazothiazole compounds including, but not limited to, tetramisole, levamisole and butamisole. In still other embodiments, the compositions of the invention may include tetrahydropyrimidine active agents including, but not limited to, pyrantel, oxantel, and morantel. Suitable organophosphate active agents include, but are not limited to, coumaphos, trichlorfon, haloxon, naftalofos and dichlorvos, heptenophos, mevinphos, monocrotophos, TEPP, and tetrachlorvinphos.

In other embodiments, the compositions may include the antinematodal compounds phenothiazine and piperazine as the neutral compound or in various salt forms, diethylcarbamazine, phenols such as disophenol, arsenicals such as arsenamide, ethanolamines such as bephenium, thenium closylate, and methyridine; cyanine dyes including pyrvinium chloride, pyrvinium pamoate and dithiazanine iodide; isothiocyanates including bitoscanate, suramin sodium, phthalofyne, and various natural products including, but not limited to, hygromycin B, α-santonin and kainic acid.

In other embodiments, the compositions of the invention may include antitrematodal agents. Suitable antitrematodal agents include, but are not limited to, the miracils such as miracil D and mirasan; praziquantel, clonazepam and its 3-methyl derivative, oltipraz, lucanthone, hycanthone, oxamniquine, amoscanate, niridazole, nitroxynil, various bisphenol compounds known in the art including hexachlorophene, bithionol, bithionol sulfoxide and menichlopholan; various salicylanilide compounds including tribromsalan, oxyclozanide, clioxanide, rafoxanide, brotianide, bromoxanide and closantel; triclabendazole, diamfenetide, clorsulon, hetolin and emetine.

Anticestodal compounds may also be advantageously used in the compositions of the invention including, but not limited to, arecoline in various salt forms, bunamidine, niclosamide, nitroscanate, paromomycin and paromomycin II.

In yet other embodiments, the compositions of the invention may include other active agents that are effective against arthropod parasites. Suitable active agents include, but are not limited to, bromocyclen, chlordane, DDT, endosulfan, lindane, methoxychlor, toxaphene, bromophos, bromophos-ethyl, carbophenothion, chlorfenvinphos, chlorpyrifos, crotoxyphos, cythioate, diazinon, dichlorenthion,, diemthoate, dioxathion, ethion, famphur, fenitrothion, fenthion, fospirate, iodofenphos, malathion, naled, phosalone, phosmet, phoxim, propetamphos, ronnel, stirofos, allethrin, cyhalothrin, cypermethrin, deltamethrin, fenvalerate, flucythrinate, permethrin, phenothrin, pyrethrins, resmethrin, benzyl benzoate, carbon disulfide, crotamiton, diflubenzuron, diphenylamine, disulfiram, isobornyl thiocyanato acetate, methoprene, monosulfiram, pirenonylbutoxide, rotenone, triphenyltin acetate, triphenyltin hydroxide, deet, dimethyl phthalate, and the compounds 1,5a,6,9,9a,9b-hexahydro-4a(4H)-dibenzofurancarboxaldehyde (MGK-11), 2-(2-ethylhexyl)-3a,4,7,7a-tetrahydro-4,7-methano-1H-isoindole-1,3(2H)dione (MGK-264), dipropyl-2,5-pyridinedicarboxylate (MGK-326) and 2-(octylthio)ethanol (MGK-874). In a particularly preferred embodiment, the compositions of the invention will include permethrin in combination with the anthelmintic compounds of the invention.

An antiparasitic agent that can be combined with the compound of the invention to form a composition can be a biologically active peptide or protein including, but not limited to, depsipeptides, which act at the neuromuscular junction by stimulating presynaptic receptors belonging to the secretin receptor family resulting in the paralysis and death of parasites. In one embodiment of the depsipeptide, the depsipeptide is emodepside (see Willson et al., Parasitology, Jan. 2003, 126(Pt 1):79-86).

In another embodiment, the compositions of the invention may comprise an active agent from the neonicotinoid class of pesticides. The neonicotinoids bind and inhibit insect specific nicotinic acetylcholine receptors. In one embodiment, the neonicotinoid insecticidal agent that may be included in a composition of the invention is imidacloprid. Imidacloprid is a well-known neonicotinoid active agent and is the key active ingredient in the topical parasiticide products Advantage®, Advantage® II, K9 Advantix®, and K9 Advantix® II sold by Bayer Animal Health. Agents of this class are described, for example, in U.S. Patent No. 4,742,060 or in EP 0 892 060.

In another embodiment, the compositions of the invention may comprise nitenpyram, another active agent of the neonicotinoid class of pesticides. Nitenpyram has the following chemical structure and is the active ingredient in the oral product CAPSTAR™ Tablets sold by Novartis Animal Health.

In certain embodiments, an insecticidal agent that can be combined with the compositions of the invention is a semicarbazone, such as metaflumizone.

In another embodiment of the invention, nodulisporic acid and its derivatives (a class of known acaricidal, anthelmintic, anti-parasitic and insecticidal agents) may be added to the compositions of the invention. These compounds are used to treat or prevent infections in humans and animals and are described, for example, in U.S. Patent No. 5,399,582, 5,962,499, 6,221,894 and 6,399,786. The compositions may include one or more of the known nodulisporic acid derivatives in the art, including all stereoisomers, such as those described in the patents cited above.

In another embodiment, anthelmintic compounds of the amino acetonitrile class (AAD) of compounds such as monepantel (ZOLVIX), and the like, may be added to the compositions of the invention. These compounds are described, for example, in WO 2004/024704 and U.S. Patent No. 7,084,280; Sager et al., Veterinary Parasitology, 2009, 159, 49-54; Kaminsky et al., Nature vol. 452, 13 March 2008, 176-181. The compositions of the invention may also include aryloazol-2-yl cyanoethylamino compounds such as those described in US Patent No. 8,088,801 to Soll et al., and thioamide derivatives of these compounds, as described in U.S. Patent No. 7,964,621.

The compositions of the invention may also be combined with paraherquamide compounds and derivatives of these compounds, including derquantel (see Ostlind et al., Research in Veterinary Science, 1990, 48, 260-61; and Ostlind et al., Medical and Veterinary Entomology, 1997, 11, 407-408). The paraherquamide family of compounds is a known class of compounds that include a spirodioxepino indole core with activity against certain parasites (see Tet. Lett. 1981, 22, 135; J. Antibiotics 1990, 43, 1380, and J. Antibiotics 1991, 44, 492). In addition, the structurally related marcfortine family of compounds, such as marcfortines A-C, are also known and may be combined with the formulations of the invention (see J. Chem. Soc.- Chem. Comm. 1980, 601 and Tet. Lett. 1981, 22, 1977). Further references to the paraherquamide derivatives can be found, for example, in WO 91/09961, WO 92/22555, WO 97/03988, WO 01/076370, WO 09/004432, U.S. Patent 5,703,078 and U.S. Patent 5,750,695.

In another particularly preferred embodiment, the compositions of the invention may advantageously include one or more compounds of the isoxazoline class of compounds. These active agents are described in WO 2007/079162, WO 2007/075459 and US 2009/0133319, WO 2007/070606 and US 2009/0143410, WO 2009/003075, WO 2009/002809, WO 2009/024541, US 7,662,972, WO 2008/122375, WO 2010/003877, WO 2010/003923, WO 2009/025983, WO 2008/150393, WO 2008/154528, WO 2009/045999, WO 2009/051956, WO 2009/126668, WO 2009/0259832, WO 2008/109760, US 2009/0156643, US 2010/0144797, US 2010/0137612, US 2011/009438 and WO 2011/075591.

Where appropriate the anthelmintic, parasiticidal and insecticial agent may also be selected from the group of compounds described above as suitable for agrochemical use.

In general, the additional active agent is included in a dose of between about 0.1 µg and about 500 mg. In some embodiments, the additional active agent may be present in a dose of about 1 mg to about 500 mg, about 1 mg to about 300 mg, or about 1 mg to about 100 mg. In other embodiments, the additional active agent may be present in a dose of about 1 mg to about 50 mg or about 1 mg to about 20 mg. In other embodiment of the invention, the additional active agent is included in a dose of about 1 µg to about 10 mg.

In another embodiment of the invention, the additional active agent is included in a dose of about 5µg/kg to about 50 mg/kg. In other embodiments, the additional active agent may be included in a dose of about 5µg/kg to about 30 mg/kg, about 5µg/kg to about 20 mg/kg or about 5µg/kg to about 10 mg/kg. In still other embodiments, the additional active agent may be included in a dose of about 10 µg/kg to about 1 mg/kg or about 50 µg/kg to about 500 µg/kg of weight of the animal. In yet another embodiment of the invention, the additional active agent is included in a dose between about 0.1 mg/kg to about 10 mg/kg of weight of animal. In still another embodiment of the invention, the additional active agent is included in a dose between about 0.5 mg/kg to 50 mg/kg.

The proportions, by weight, of the aryloazol-2-yl-cyanoethylamino compound and the additional active agent are for example between about 5/1 and about 10,000/1. However, one of ordinary skill in the art would be able to select the appropriate ratio of aryloazol-2-yl-cyanoethylamino compound and the additional active agent for the intended host and use thereof.

Also described is the process of making the novel anthelmintic compounds of the invention and of reference examples. The compounds of the invention and the reference examples may be prepared according to the processes described herein or by the application or adaptation of known methods (i.e. methods heretofore used or described in the chemical literature). For example, in some embodiments, the compounds of the invention and the reference examples may be prepared by methods described in WO 2009/077527 A1, WO 2010/115688 A1, WO 2010/146083 A1 and EP 2 468 096 A1, or by adaptation of methods described in these publications.

AIBN

azobisisobutyronitrile

BINAP

2,2'-bis(diphenylphosphino)-1,1'-binaphthyl

BSA

bovine serum albumin

BOC

tert-butoxycarbonyl

dba

dibenzylidineacetone

CDI

1,1'-carbonyldiimidazole

CI

chemical ionization

DEGMME

diethylene glycol monomethyl ether

DIAD

diisopropylazodicarboxylate

DIEA

diisopropylethylamine

DMF

N,N-dimethylformamide

DMSO

dimethylsulfoxide

DPPA

diphenylphosphoryl azide

EDAC·HCl

1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride

ES

electrospray

EtOAc

ethyl acetate

HATU

1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5 b]pyridinium 3-oxide hexafluorophosphate

HBSS

Hank's Balanced Salt Solution

HOBt

1-hydroxybenzotriazole

NBS

N-bromosuccinimde

NMM

N-methylmorpholine

POM

polyoxymethylene (formaldehyde polymer)

TBAF

tert-butyl ammonium fluoride

TBHP

tert-butyl hydrogen peroxide

TFA

trifluoroacetic acid

TFAA

trifluoroacetic acid anhydride

THF

tetrahydrofuran

The aryl fluoride (2 g, 10.6 mmol) was placed in a 100 ml round-bottomed flask and stirred in 20 ml acetonitrile at room temperature. Potassium carbonate (3.3 g, 23.9 mmol, 2.2 eq) and 1,4-trans-amino-cyclohexanol (1.34 g, 11.6 mmol, 1.1 eq) were added and the mixture was then heated at 90 °C overnight. The mixture was cooled to room temperature and then concentrated under vacuum. The crude material was purified by silica gel chromatography using 20 - 40 % ethyl acetate in petroleum ether to elute. The product-containing fractions were combined and concentrated under vacuum to provide 1 g (33 %) of the desired aniline as a yellow oil. (ES, m/z): [M+H]⁺ 285.0;¹H NMR (300 MHz, DMSO): δ 8.04 (d, J = 9.3 Hz, 1H), 7.42 (d, J = 7.8 Hz, 1H), 7.06 (d, J = 1.8 Hz, 1H), 6.82 - 6.86 (m, 1H), 4.59 (d, J = 4.2 Hz, 1H), 3.39 - 3.49 (m, 2H), 1.78 - 1.94 (m, 4H), 1.18 - 1.32 (m, 4H).

In a 250 ml round-bottomed flask under nitrogen, a solution of 4-(4-nitro-3-trifluoromethyl-phenylamino)-cyclohexanol (1 g, 3.5 mmol) in 20 ml of THF was cooled using an external ice bath. Sodium hydride (254 mg, 10.6 mmol, 3 eq) was then added and the mixture was stirred at ∼ 0-5 °C for 20 minutes before adding the tert-butyl-2-bromoacetate (700 mg, 3.6 mmol, 1 eq). The solution was allowed to warm to room temperature while stirring for 2 hours. The reaction was then diluted using 50 ml of water. The mixture was then extracted with 3 x 50 ml of ethyl acetate. The organic layers were combined, dried over sodium sulfate, filtered, and concentrated under vacuum. The crude material was purified by silica gel chromatography using 10 - 20 % ethyl acetate in petroleum ether to elute. The product-containing fractions were combined and concentrated under vacuum to provide 0.5 g (36 %) of the desired ester as an off-white powder. (ES, m/z): [M+H]⁺ 399.0.¹H NMR (300 MHz, CDCl₃): δ 7.53 (d, J = 8.7 Hz, 1H), 6.83 (s, 1H), 6.65 - 6.83 (t, J = 6.9 Hz, 1H), 4.01 (s, 2H), 3.36 - 3.42 (m, 2H), 2.12 - 2.15 (m, 4H), 1.49 (s, 9H), 1.24 - 1.32 (m, 4H).

To a solution of tert-butyl 2-(4-(4-nitro-3-(trifluoromethyl)phenylamino)cyclohexyloxy)acetate (150 mg, 0.38 mmol) in dichloromethane (20 ml) was added trifluoroacetic acid (500 mg, 4.4 mmol, 2.6 eq). The resulting solution was stirred for 2 hours at room temperature and then concentrated under vacuum. The residue was dissolved in water (10 ml) and then extracted with n-butanol (2 x 50 ml). The organic layers were combined, dried over sodium sulfate, filtered, and concentrated under vacuum. The crude material was purified by silica gel chromatography using 3% methanol in dichloromethane to elute. The product-containing fractions were combined and concentrated under vacuum to afford 41.7 mg (32 %) of 2-(4-(4-cyano-3-(trifluoromethyl)phenylamino)cyclohexyloxy)acetic acid as a light yellow oil. (ES, m/z): [M+H]⁺ 343.1;¹H NMR (300 MHz, CD₃OD): δ 7.58 (d, J = 8.7 Hz, 1H), 6.94 (d, J = 2.1 Hz, 1H), 6.79 - 6.83 (dd, J = 2.1 Hz, 8.7 Hz, 1H), 4.12 (s, 2H), 3.35 - 3.51 (m, 2H), 2.04 - 2.20 (m, 4H), 1.24 - 1.53 (m, 4H).