Preparation of Arylmercapturic Acids by S-Arylation of N,N′-Diacetylcystine

A simple convenient method has been developed for the preparation of N-acetyl-S-arylcysteines based on the Chan-Lam-Evans arylation of N,N'-diacetylcystine dimethyl ester with arylboronic acids and used to synthesize a series of aryl-mercapturic acids. Unlike copper-mediated N-arylation, the S-arylation of neither cysteine nor cystine derivatives proceeded satisfactorily in the presence of air. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)