Retroviral protease inhibitors

Compound represented by the formula:

• ##STR386## or a pharmaceutically acceptable salt, prodrug or ester thereof, wherein R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, alkanoyl, aroyl, aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, alkoxyalkanoyl, hydroxyalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkoxycarbonyl, heteroaroyl, alkyl, aralkyl, aminoalkanoyl, aminocarbonyl, alkylaminoalkanoyl, dialkylaminoalkanoyl, alkylaminocarbonyl or dialkylaminocarbonyl radicals;
• R' represents hydrogen or alkyl radicals;
• or R and R' together with the nitrogen to which they are attached form a heterocycloalkyl or heteroaryl radical;
• R.sup.1 represents hydrogen, --CH.sub.2 SO.sub.2 NH.sub.2, --CO.sub.2 CH.sub.3, --CH.sub.2 CO.sub.2 CH.sub.3, --CO.sub.2 H, --CH.sub.2 CO.sub.2 H, --CH.sub.2 CH.sub.2 CONH.sub.2, --CH.sub.2 CONH.sub.2, --CONH.sub.2, --CONHCH.sub.3, --CON(CH.sub.3).sub.2, --CH.sub.2 CONHCH.sub.3, --CH.sub.2 CON(CH.sub.3).sub.2, --CH.sub.2 SCH.sub.3, --CH.sub.2 S O!CH.sub.3, --CH.sub.2 S O!.sub.2 CH.sub.3, --C(CH.sub.3).sub.2 (SCH.sub.3), --C(CH.sub.3).sub.2 (S O!CH.sub.3), --C(CH.sub.3).sub.2 (S O!.sub.2 CH.sub.3), alkyl, aminoalkyl, hydroxyalkyl, cyanoalkyl, haloalkyl, alkenyl, alkynyl or cycloalkyl radicals;
• R.sup.1' represents hydrogen or alkyl radicals;
• R.sup.1" represents hydrogen, alkyl, CO.sub.2 CH.sub.3 or CONH.sub.2 radicals;
• or R.sup.1" together with R.sup.1 and the carbon atoms to which they are attached, represent a cycloalkyl radical;
• R.sup.2 represents alkyl, aryl, cycloalkyl, cycloalkylalkyl, or aralkyl radicals, which radicals are optionally substituted with alkyl, halogen, --NO.sub.2, OR.sup.9 or SR.sup.9 radicals, wherein R.sup.9 represents hydrogen or alkyl radicals;
• R.sup.3 represents alkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl, heterocycloalkylalkyl, aryl, aralkyl, or heteroaralkyl radicals;
• R.sup.4 represents alkyl, cycloalkyl or aralkyl radicals;
• R.sup.6 represents hydrogen and alkyl radicals;
• t represents 0 or 1;
• and
• Y and Y' independently represent O or S;
• and
• wherein alkyl, alone or in combination, is a straight-chain or branched-chain alkyl radical containing from 1 to 8 carbon atoms;
• alkenyl, alone or in combination, is a straight-chain or branched-chain hydrocarbon radial having one or more double bonds and containing from 2 to 8 carbon atoms;
• alkynyl, alone or in combination, is a straight-chain hydrocarbon radical having one or more triple bonds and containing from 2 to about 10 carbon atoms;
• cycloalkyl, alone or in combination, is a saturated or partially saturated monocyclic, bicyclic or tricyclic alkyl radical wherein each cyclic moiety contains from 3 to 8 carbon atoms;
• aryl, alone or in combination, is an unsubstituted phenyl radical, unsubstituted naphthyl radical, or phenyl or naphthyl radical substituted with one or more alkyl, alkoxy, halogen, hydroxy, amino, nitro, cyano or haloalkyl radicals;
• heterocycloalkyl, alone or in combination, is a saturated or partially unsaturated monocyclic heterocycle, having 5 to 6 ring members wherein at least one ring member is a nitrogen, oxygen or sulphur atom and which is unsubstituted or substituted on one or more substitutable carbon atoms with halogen, alkyl, alkoxy or oxo, or on a ring secondary nitrogen atom with alkyl, aralkoxycarbonyl, alkanoyl, phenyl or phenylalkyl;
• and heteroaryl, alone or in combination, is an aromatic monocyclic, bicyclic or tricyclic heterocycle, each ring having from 5 to 11 members wherein at least one ring member is a nitrogen, oxygen or sulphur atom and which is unsubstituted or substituted on one or more substitutable carbon atoms with halogen, alkyl, alkoxy or oxo, on a ring secondary nitrogen atom with alkyl, aralkoxycarbonyl, alkanoyl, phenyl or phenylalkyl, or on a ring tertiary nitrogen atom by oxido.