Azo-coupling of pyrazole-3(5)-diazonium chlorides with cyanothioacetamide: a convenient synthesis of pyrazolo[5,1-c][1,2,4]triazine-3-carbothioamides
作者:Irina V. Ledenyova、Vitaly V. Didenko、Victor V. Dotsenko、Khidmet S. Shikhaliev
DOI:10.1016/j.tetlet.2014.01.010
日期:2014.2
Cyanothioacetamide reacts with pyrazole-3(5)-diazonium chlorides to afford pyrazolo[5,1-c][1,2,4]triazine-3-carbothioamides 5. The latter can be oxidized with H2O2 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 alpha-bromo ketones leads to 3-(thiazol-2-yl)pyrazolo[5,1-c][1,2,4]triazines. (C) 2014 Elsevier Ltd. All rights reserved.