Reactivity of 2-Aminothiazole and 2- or 6-Aminobenzothiazole Derivatives Towards the Triphenylbismuth Diacetate/Catalytic Copper Diacetate Phenylation System

The copper diacetate catalysed reaction of triphenylbismuth diacetate with 6‐aminobenzothiazole compounds afforded selectively the 6‐phenylamino derivatives in good to high yields. A similar reaction with 2‐aminothiazole or 2‐aminobenzothiazole compounds gave mixtures of the monophenylated and diphenylated products 2‐phenylaminothiazole and 2‐(N‐phenylamino)‐3‐N′‐phenylthiazole derivatives, respectively, with the diphenyl product being predominant. Semi‐empirical calculations with the SAM1/D and CHAIN methods performed on the evolution of a 2‐aminobenzothiazole − copper(III) intermediate were in good qualitative agreement with the experimental results. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)