Imido, amido and amino derivatives of mercaptoacyl prolines and pipecolic acids

A compound having the formula ##STR7## wherein R.sub.1 and R.sub.2 together with the nitrogen atom to which they are attached are 1-imidazolyl, 1-pyrrolidinyl-2,5-dione, 3-alkyl-1-pyrrolidinyl-2,5-dione, 3-aryl-1-pyrrolidinyl-2,5-dione, 1-piperidinyl-2,6-dione, 3-alkyl-1-piperidinyl-2,6-dione, 3-aryl-1-piperidinyl-2,6-dione, or 2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl;

• R.sub.3 is hydrogen, alkyl, aryl, arylalkyl, alkanoyl or arylcarbonyl;
• R.sub.4 is hydrogen, alkyl, alkylthio, or trifluoromethyl;
• R.sub.5 is hydrogen, alkyl or arylalkyl;
• n is 0, 1 or 2;
• and
• p is 1 or 2;
• or a non-toxic, physiologically acceptable salt thereof, or symmetrical dimer thereof;
• wherein the term "aryl" refers to phenyl, 1-naphthyl, 2-naphthyl, or phenyl substituted with halogen, alkyl, alkoxy, alkylthio, hydroxy, alkanoyl, nitro, amino, dialkylamino, phenyl or trifluoromethyl groups;
• the term "alkanoyl" refers to groups having up to 9 carbon atoms;
• and the terms "alkyl" and "alkoxy" refer to groups having 1 to 8 carbon atoms.