A convenient modified synthesis of 5-pyridinyl-1,3,4-thiadiazole-2-carboxamides

Abstract

A general one-pot procedure is developed for the synthesis of 5-pyridinyl-1,3,4-thiadiazole-2-carboxamides by the reaction of pyridine carboxaldehydes with oxamic acid thiohydrazides.

Synthesis of (2-chloroquinolin-3-yl)-1,3,4-thiadiazole-2-carboxamides

“…It should be noted that in contrast to our previous work 14 on the reactions of aromatic aldehydes with oxamic acid thiohydrazides, the autoxidation of dihydrothiadi-azoles 6a-d into the corresponding thiadiazoles does not occur. It was possible to convert compounds 6a-d into (2-chloroquinolin-3-yl)-1,3,4-thiadiazole-2-carboxamides 8a-d upon their treatment with DDQ in ethanol (Scheme 5).…”