Mercaptoacyl derivatives of 4-disubstituted prolines and 4-substituted dehydroprolines

A composition useful for treating hypertension comprising a pharmaceutically acceptable carrier and one or more hypotensive agents of the formula ##STR35## and pharmaceutically acceptable salts thereof wherein R is hydrogen or lower alkyl;

• R.sub.1 is lower alkenyl, lower alkynyl, ##STR36## --(CH.sub.2).sub.m --cycloalkyl wherein said cycloalkyl ring is of 3 to 7 carbon atoms, .alpha.-naphthyl, .beta.-naphthyl, ##STR37## wherein said --(CH.sub.2).sub.m -- bridge is attached to an available carbon atom, or ##STR38## wherein said --(CH.sub.2).sub.m -- bridge is attached to an available carbon atom;
• R.sub.2 and R.sub.3 are independently selected from the group consisting of hydrogen, lower alky, lower alkylthio, and halo substituted lower alkyl;
• n is zero, one or two;
• R.sub.5 is hydrogen, ##STR39## R.sub.7 is lower alkyl of 1 to 6 carbons, lower alkyl substituted with one or more chloro, bromo or fluoro groups, --(CH.sub.2).sub.m cycloalkyl wherein said cycloalkyl ring is of 3 to 7 carbons ##STR40## wherein said --(CH.sub.2).sub.m -- bridge is attached to an available carbon atom, and ##STR41## wherein said --(CH.sub.2).sub.m -- bridge is attached to an available carbon atom;
• R.sub.6 is hydrogen, lower alkyl of 1 to 4 carbons, lower alkoxy of 1 to 4 carbons, lower alkylthio of 1 to 4 carbons, chloro, fluoro, bromo, trifluoromethyl, or hydroxy;
• m is zero, one, two or three;
• and
• X is O or S.