Nitrogen and sulfur containing heterocycles. 50. Synthesis and reactions of 6-oxopyrimido[4,5-b][1,4]thiazine-7-carboxylic acid derivatives

Article abstract of DOI:10.1007/BF02251635

Reaction of 5-amino-6 mercaptopyrimidines with diethyl bromomalonate gave ethyl 6-oxopyrimido-[4,5-b][1,4]thiazine-7-carboxylates, from which there was synthesized a series of derivatives at the carboxyl group (amides, hydrazides, and, from the latter, urethanes). Desulfurization of the 6-oxo-pyrimidothiazine-7-carboxylic acid esters gave N-(pyrimidin-5-yl)monoamides of ethyl malonate. 1999 KluwerAcademic/Plenum Publishers.