Substituted pipecolinic and acid derivatives as HIV protease inhibitors.

Disclosed herein are compounds of formula 1 wherein x is a terminal group, for example, an aryloxycarbonyl, an alkanoyl or an optionally mono or disubstituted carbamoyl, b is absent or an amino acid residue, for example, val or asn, r1 is hydrogen or a ring substituent, for example, fluoro or methyl, r2 is alkyl and y is a ring substituent for example, phenoxy, 2-pyridinylmethoxy, phenylthio or 2-pyridinylthio. The compounds inhibit the activity of human immunodeficiency virus (hiv)protease and interfere with hiv induced cytopathogenic effects in human cells. These properties render the compounds useful for combating hiv infections.