Efficient, one-pot synthesis of triazolothiadiazinyl-pyrazolone and pyrazolyl-triazolothiadiazine derivatives via multicomponent reaction

Abstract

A one-pot, multicomponent reaction of 3-(2-bromo acetyl)coumarins, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and different derivatives of ethyl 2-(2-(aryl)hydra-zono)-3-oxobutanoates provide an efficient and direct method for the synthesis of4-(arylydrazono)-3-methyl-1-(6-(coumarin-3-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadia-zin-3-yl)-1H-pyrazol-5(4H)-ones (4a–h). A similar methodology was also developed for thesynthesis of pyrazolyl-triazolothiadiazines (9a–f) using acetyl acetone, 4-amino-5-hydra-zino-4H-[1,2,4]triazole-3-thiol, and different derivatives of phenacylbromide. The resultingproducts were characterized by analytical and spectral data.