4-arylisoindole analgesics

A compound having analgesic activity of the general formula:

• ##STR112## including the purified stereoisomers and pharmaceutically acceptable salts thereof, wherein:
• ##STR113## R.sup.a1 is selected from the group consisting of hydroxy, halogen, C.sub.1-4 alkyl, substituted C.sub.1-4 alkyl (wherein the substituent is C.sub.1-4 alkoxy, hydroxy or perhalo), C.sub.1-4 alkoxy, substituted C.sub.1-4 alkoxy (wherein the substituent is perfluoro), C.sub.1-4 alkylthio, cyano, nitro, amino, C.sub.1-4 alkylamino, diC.sub.1-4 alkylamino, C.sub.1-4 alkylsulfonyl, C.sub.1-4 alkylsulfinyl, phenyl, phenylthio, C.sub.1-4 acylamino, carboxy, C.sub.1-4 acyl and benzoyl;
• R.sup.a2 is selected from the group consisting of halogen or C.sub.1-4 alkyl;
• R.sup.b is 5-, 6-, or 7-position substituted and selected from the group consisting of hydrogen and C.sub.1-4 alkyl;
• and
• R.sup.c is selected from the group consisting of hydrogen, C.sub.1-4 alkyl, substituted C.sub.1-4 alkyl (wherein the substituent is one or two phenyl groups or diC.sub.1-4 alkylamino), C.sub.1-4 alkenyl, benzyl, C.sub.1-6 cycloalkylmethyl and C.sub.1-6 cycloalkyl;
• with the proviso that there is 0 or 1 unsaturated bond in the isoindole ring and with the proviso that where the stereoisomer is:
• a) the 3a.beta., 4.beta., 7a.alpha. diastereomer, then a double bond joins the 5- and 6-position carbons or the 6- and 7-position carbons;
• b) the 3a.beta., 4.alpha., 7a.alpha. or the 3a.beta., 4.alpha., 7a.beta. diastereomers, then the double bond joins the 5- and 6-position carbons;
• and
• c) the 3a.beta., 4.alpha., 7a.beta.diastereomer, then the double bond joins the 6- and 7-position carbons.