04-12-2014 дата публикации
Номер: US20140357900A1
Принадлежит:
Disclosed is a preparation method of the lycopene intermediate 3-methyl-4,4-dialkoxy-1-butaldehyde. The preparation method comprises the following steps: (1) reacting 2-methyl-3,3-dialkoxy-1-halopropane with magnesium powder in the solvent of anhydrous tetrahydrofuran at a temperature of 45˜65° C. to generate a mixture of Grignard reagents under the protection of an inert gas; and (2) adding N,N-disubstituted carboxamide to the mixture of Grignard reagents and reacting at a temperature of 10° C.˜35° C. to obtain 3-methyl-4,4-dialkoxy-1-butaldehyde. The process route of the present invention is simple and direct, the operation is easy, the conditions are mild and the yield is good, and thus the invention has commercial value. 2. The preparation method according to claim 1 , wherein the alkyl is methyl or ethyl.3. The preparation method according to claim 1 , wherein the 2-methyl-3 claim 1 ,3-dialkoxy-1-halopropane is 2-methyl-3 claim 1 ,3-dimethoxy-1-chloropropane claim 1 , 2-methyl-3 claim 1 ,3-dimethoxy-1-bromopropane claim 1 , 2-methyl-3 claim 1 ,3-diethoxy-1-chloropropane claim 1 , and 2-methyl-3 claim 1 ,3-diethoxy-1-bromopropane.4. The preparation method according to claim 1 , wherein the N claim 1 ,N-disubstituted carboxamide is N claim 1 , N-dimethyl formamide or N-formyl piperidine.5. The preparation method according to claim 1 , wherein a molar ratio of 2-methyl-3 claim 1 ,3-dialkoxy-1-halopropane to the magnesium powder is 1:1.0˜1.5.6. The preparation method according to claim 1 , wherein a molar ratio of 2-methyl-3 claim 1 , 3-dialkoxy-1-halopropane to N claim 1 ,N-disubstituted carboxamide is 1:1.0˜1.5.7. The preparation method according to claim 1 , wherein claim 1 , the reactants of step (1) further comprise iodine. This application is a national phase application of PCT/CN2012/001667, filed on Dec. 10, 2012, which claims priority to Chinese Application No. 201110440217.0 filed on Dec. 26, 2011.The present invention relates to a pharmaceutical chemical ...
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