Synthesis of 5-(5-amino-1H-pyrazol-1-yl)-1,2,3-thiadiazole-4-carboxylic acid ethyl esters and their cyclization into pyrazolo[1,5-a][1,2,3]thiadiazolo[4,5-e]pyrimidin-4(5H)-ones

Abstract

A method for the synthesis of novel 1H-pyrazol-1-yl-1,2,3-thiadiazole derivatives has been proposed and their intramolecular cyclization to pyrazolo[1,5-a][1,2,3]thiadiazolo[4,5-e]pyrimidin-4(5H)-ones, previously unknown fused tricyclic heterocycles, has been studied.