A facile method for the synthesis of pyridazino[4,5-b][1,4]thiazine-diones via Smiles rearrangement

An efficient one-pot tandem method for the synthesis of pyridazino[4,5-b][1,4]thiazine-diones via Smiles rearrangement was developed. A number of ideal products were obtained with high yields without any byproducts. More specifically, this transition metal-free process is an environmentally friendly, economical, and efficient method for preparation of mixture-based heterocyclic libraries.