Synthesis and reactions of pyrazolo[5,1-c][1,2,4]triazine-3-carbothioamides

Abstract

Cyanothioacetamide reacts with pyrazole-3(5)-diazonium chlorides under mild conditions to afford pyrazolo[5,1-c][1,2,4]triazine-3-carbothioamides. The latter can be oxidized with H 2 O 2 to give either pyrazolo[5,1-c][1,2,4]triazine-3-carboxamides or 1,2,4-thiadiazole derivatives, depending on the reaction conditions. The Hantzsch-type reaction of thioamides 5 with α-bromo ketones leads to 3-(thiazol-2-yl)pyrazolo [5,1-c][1,2,4]triazines.