Coumarin derivatives as protease inhibitors and antiviral agents

A compound or a pharmaceutically acceptable salt thereof of formula ##STR12## wherein X is OR.sub.1 or SH wherein R.sub.1 is hydrogen or COR.sub.2 wherein R.sub.2 is a straight or branched alkyl chain containing 1 to 5 carbon atoms, a cyclic alkyl containing 3 to 6 carbon atoms, or a hydrogen atom;

• Z is oxygen or sulfur;
• Y is oxygen;
• W is oxygen, NR.sub.3, C(R.sub.3).sub.2, NCOV.sub.n4 R.sub.3, NR.sub.3 COV.sub.n4, CO, CH.dbd.CH, S(O).sub.n3, C.tbd.C, CNOR4, or CR.sub.3 OR.sub.3 wherein V is oxygen, sulfur, NR.sub.3, or CHR.sub.3 ;
• R.sub.3 is (CH.sub.2).sub.n3 Ar wherein Ar is phenyl, naphthyl, or a substituted derivative thereof wherein the substituents are one or more of F, Cl, Br, OR.sub.4, N(R.sub.4).sub.2, NO.sub.2, CO.sub.2 R.sub.4, CON(R.sub.4).sub.2, COR.sub.4, R.sub.4, OCH.sub.2 O, OCH.sub.2 CH.sub.2 O, or CN;
• R.sub.4 is hydrogen, a straight or branched alkyl group consisting of 1 to 5 carbon atoms, a cycloalkyl consisting of 3 to 6 carbon atoms, or a substituted derivative thereof wherein the substituents are one or more of CO.sub.2 R.sub.2, CON(R.sub.2).sub.2, F, OR.sub.2, phenyl, naphthyl, or CF.sub.3 ;
• n1, n2, n3, and n4 are integers of from 0 to 4, 0 to 4, 0 to 2, and 0 to 1, respectively, with the proviso that n2 is zero when intra-chain n4 is zero, and with the further proviso that n2 is of from two to four when two intra-chain groups W are heteroatoms;
• and
• A and B are independently F, Cl, Br, OR.sub.4, N(R.sub.4).sub.2, NO.sub.2, CO.sub.2 R.sub.4, CON(R.sub.4).sub.2, COR.sub.4, R.sub.4, OCH.sub.2 O, OCH.sub.2 CH.sub.2 O, or CN.