Peptide derivatives

Claim 1

A compound of formula Ia, Ib or Ic: ##STR5## wherein R 1 is an alkyl group containing from 1 to 5 carbon atoms; R 2 and R 5 are each selected independently from the group consisting of: (I) an alkyl group containing from 1 to 10 carbons; and (II) an alkyl group containing from 1 to 6 carbon atoms substituted by at least one member selected from the group consisting of: (a) hydroxy; (b) amino; (c) alkylamino containing from 1 to 6 carbons; (d) dialkylamino wherein each alkyl group contains from 1 to 6 carbons; (e) alkanoyl containing from 1 to 6 carbons; (f) arylcarbonyl wherein the aryl contains 6, 10 or 12 carbons; (g) aralkanoyl containing 8 to 13 carbons; (h) amido which may be attached to the alkyl group via either a nitrogen or carbon of said amido; (i) alkylcarbonylamino wherein the alkyl group contains from 1 to 6 carbons; (j) alkylaminocarbonyl wherein the alkyl group contains from 1 to 6 carbons; (k) arylcarbonylamino wherein the aryl group contains 6, 10 or 12 carbons; (l) aralkylcarbonylamino wherein the aralkyl group contains from 7 to 13 carbons; (m) arylaminocarbonyl wherein the aryl group contains 6, 10 or 12 carbons; (n) aralkylaminocarbonyl wherein the aralkyl group contains from 7 to 13 carbons; (o) carboxy; (p) aryloxycarbonyl wherein the aryl group contains 6, 10 or 12 carbons; (q) aralkoxycarbonyl wherein the aralkoxy group contains from 7 to 13 carbons; (r) alkanoyloxy containing from 1 to 6 carbons; (s) aroyloxy wherein the aryl portion contains 6, 10 or 12 carbons; (t) aralkanoyloxy containing from 8 to 14 carbons; (u) alkylsulfonamido wherein the alkyl group contains from 1 to 6 carbons; (v) aralkylsulfonamido wherein the aralkyl group contains from 7 to 13 carbons; (w) arylsulfonamido wherein the aryl group contains 6, 10 or 12 carbons; (x) acylsulfonamido (i.e. acylaminosulfonyl and sulfonylaminocarbonyl) including acylsulfonamido wherein the acyl group contains 1 to 7 carbons when it is the terminal portion of the acylsulfonamide and provided that when the acylsulfonamido contains an aryl the aryl may be further substituted by a member selected from fluoro, chloro, bromo, iodo and nitro; (y) alkoxycarbonyl wherein the alkoxy group contains from 1 to 6 carbons; (z) aralkoxycarbonylamino wherein the aralkoxy group contains from 8 to 13 carbons; (aa) aryloxycarbonylamino wherein the aryloxy group contains 6, 10 or 12 carbons; (bb) alkoxycarbonylamino wherein the alkyloxy group contains from 1 to 6 carbons; (cc) aryl containing 6, 10 or 12 carbons; (dd) aryl containing 6, 10 or 12 carbons and substituted by 1 to 3 members selected from the group consisting of chloro, bromo, iodo, fluoro, trifluoromethyl, hydroxy, alkyl (1 to 6 carbons), alkoxy (1 to 6 carbons), alkoxycarbonyl (1 to 6 carbons), carboxy, 5-tetrazolo, and acylsufonamido (i.e. acylaminosulfonyl and sulfonylaminocarbonyl) (1 to 15 carbons) and provided that when the acylsulfonamido contains an aryl the aryl may be further substituted by a member selected from fluoro, chloro, bromo, iodo and nitro; (ee) cycloalkyl containing from 3 to 15 carbons; (ff) alkylureido wherein the alkyl group contains from 1 to 6 carbons; (gg) aralkylureido wherein the aralkyl group contains from 8 to 13 carbons; (hh) arylureido wherein the aryl group contains 6, 10 or 12 carbons; R 3 is an aryl group containing 6, 10 or 12 carbons suitably substituted by acylsulfonamido (i.e. acylaminosulfonyl and sulfonylaminocarbonyl) containing from 1 to 15 carbons, and provided that when the acylsulfonamido contains an aryl the aryl may be further substituted by fluoro, chloro, bromo, iodo or nitro; R 4 and R 6 are independently hydrogen or methyl; n is 0, 1 or 2; and A is selected from the group consisting of ##STR6## and where appropriate, the acid- and base-addition salts thereof and provided that: (1) alkyls may be straight or branched chain; (2) no carbon of an alkyl may be directly bonded to two heteroatoms; and (3) no heteroatom may be directly bonded to a sulfur, nitrogen or oxygen.