Synthesis and addition reactions of 1,3-Thiazole-5(4H)-thione Oxides

Abstract

1,3-Thiazole-5(4H)-thione oxides 2 were prepared by oxidation of the corresponding 1,3-thiazole-5(4H)-thiones 1 with m-chloroperbenzoic acid (Table 1). Addition reactions of 2 with organolithium and Grignard reagents yielded 4,5-dihydro-4,4-dimethyl-1,3-thiazol-5-myelthyl sulfoxides of type 4 via thiophilic attack (Table 2). Whereas the reaction with the organolithium compounds proceeded with fair-to-excellent yields, the Grignard reagents reacted only very sluggishly.The sulfides 4 could also be prepared via oxidation of 4,5-dihydro-4,4-dimethyl-5-(methyIthio)-1,3-thiazoIes of type 3 with m-chloroperbenzoic acid, together with the corresponding sulfones 5 (Scheme I ) .