Ring opening in a non-basic medium of 2-methyl-6-nitrobenzothiazole and H–D exchange at the 2-methyl promoted by silver(I)

Abstract

Silver(I) promotes H–D exchange at the 2-methyl group of 2-methyl-6-nitrobenzothiazole (mnbt) in the presence of CD₃OD in dimethyl sulphoxide (dmso). Moreover, the alcohol in dmso causes nucleophilic attack at the C² of mnbt with subsequent cleavage of the C–S bond and opening of the thiazole ring to afford (2-amino-5-nitrobenzenethiolato-S)silver(I). In a similar reaction, the unsubstituted benzothiazole ring is opened to afford the silver(I) salt of 2-aminobenzenethiol. The role of the electronic structure of silver(I) in the ring-opening reaction is discussed and compared with the behaviour of analogous complexes of iron(II) and rhodium(I) with MeOH.