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 arylmercapturic acids. Unlike copper‐mediated N ‐arylation, the S ‐arylation of neither cysteine nor cystine derivatives proceeded satisfactorily in the presence of air.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)