Abstract: The invention relates to compounds of the formula I, in which R1 and R2 are, independently of each other, lower alkyl or lower alkoxy-lower alkyl; R3 and R4 are, independently of each other, sec-lower alkyl or tert-lower alkyl; R5 is phenyl or cyclohexyl; and R6 and R7 are, independently of each other, lower alkyl, or, together with the linking nitrogen atom, pyrrolidino, piperidino, 4-lower alkylpiperidino, 1,2,4-triazol-1-yl or 1,2,4-triazol-4-yl; or a salt thereof, provided that at least one salt-forming group is present. These compounds are inhibitors of HIV protease and are therefore suitable, for example, for treating AIDS or its preliminary stages.

Abstract: There are described compounds of formula I*, wherein R1 is lower alkoxycarbonyl, R2 is secondary or tertiary lower alkyl or lower alkylthio-lower alkyl, R3 is phenyl that is unsubstituted or substituted by one or more lower alkoxy radicals, or C4-C8cycloalkyl, R4 is phenyl or cyclohexyl each substituted in the 4-position by unsaturated heterocyclyl that is bonded by way of a ring carbon atom, has from 5 to 8 ring atoms, contains from 1 to 4 hetero atoms selected from nitrogen, oxygen, sulfur, suffinyl (—SO—) and sulfonyl (—SO2—) and is unsubstituted or substituted by lower alkyl or by phenyl-lower alkyl, R5, independently of R2, has one of the meanings mentioned for R2, and R6, independently of R1, is lower alkoxycarbonyl, or salts thereof, provided that at least one salt-forming group is present. The compounds are inhibitors of retroviral aspartate protease and can be used, for example, in the treatment of AIDS.

Abstract: The invention relates to compounds of formula (I): wherein R1 and R10 are each independently of the other lower alkoxycarbonyl; either R2, R3 and R4 are each independently of the other C1-C4alkyl and R7, R8 and R9 are each selected from hydrogen and C1-C4alkyl, with not more than 2 of the radicals being hydrogen; or R7, R8 and R9 are each independently of the other C1-C4alkyl and R2, R3 and R4 are each selected from hydrogen and C1-C4alkyl, with 1 or 2 of the radicals being hydrogen; R5 is phenyl or cyclohexyl; and R6 is phenyl or cyanophenyl; or salts thereof; those compounds are inhibitors of retroviral aspartate proteases and are effective, for example, against HIV.