synthesis of inhibitors 34-40, has already been described.'The basecatalyzed ester hydrolysis was modified by using aqueous DMSO in place of aqueous MeOH. In this medium the reaction was essentially complete in 1 hr at 80-85", with yields of up to 79% being obtained. N-Arylamides (Method A). Conversion of the nitro-substituted acid to the acid chloride and condensation with the arylamine in toluene at reflux was performed as ...