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：Ledenyova Irina V^*; Didenko Vitaly V; Dotsenko Victor V; Shikhaliev Khidmet S

来源：Tetrahedron Letters, 2014, 55(6): 1239-1242.

DOI：10.1016/j.tetlet.2014.01.010

• Azo-coupling
• Cyanothioacetamide
• Hantzsch thiazole synthesis
• Pyrazole-3(5)-diazonium salts
• Pyrazolo[5,1-c][1,2,4]triazines
• Oxidation of thioamides

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.

• 出版日期2014-2-5