NEW MATERIAL:A compound of formula I [R1 is H, 1-4C alkyl; R2 is a carbon ring or a heterocyclic ring which may substituted with R3; R3 is halogen, trihalomethyl, hydroxyl, 1-15C alkyl; Z is H, -COR9 (R9 is 1-4C alkyl, substituted phenyl); (A) is phenyl substituted with R13 (R13 is H, halogen) or 4-7C cycloalkyl; when m=0, n is 1 to 4, when n=0, m is 1 to 4], its salt or acid adduct.

EXAMPLE: N-(3-Mercapto-2RS-cyclohexylmethylpropionyl)-α-anilino-L-glutamic acid.

USE: Analgesic, antianxiety or anticonvulsant.

PREPARATION: In accordance with the reaction equations, an amine of formula II (t-Bu is tertiary butyl) is allowed to react with a carboxylic acid to form an amide bond. The reaction 2 is conducted using 2-mercaptoethylamine in a solvent such as methylene chloride to give the subject compound.