Simple Synthesis of Fused Thiazolo[4,5-b]pyridines through Successive SNAr Processes

Abstract

AbstractA convenient process is described for the synthesis of novel thiazolo[4,5-b]pyridines fused with triazole or pyrimidine rings. The base-promoted reactions of 2-chloro-3-nitropyridines with 1,3-(S,N)-binucleophiles (triazole-5-thiols, 4-oxopyrimidine-2-thiones) resulted in nucleophilic substitution of the chlorine atom and subsequent S–N-type Smiles rearrangement followed by nucleophilic substitution of the nitro group. Reactions with pyrimidine-2-thiones were carried out as one-pot processes while, in the case of triazole-5-thiols, isolation of intermediate substitution products was found to be preferable.