Novel Synthesis of 2,4-Dihydro-5-amino[1,2,4]triazol-3-ones from 1,3-Disubstituted Thioureas

作者：Jin Can; Liu Chuangwei; Su Weike^*

来源：Synlett, 2009, 2009(4): 607-610.

DOI：10.1055/s-0028-1087563

• cyclizations
• thiourea
• regioselectivity
• 1,2,4-triazol-3-ones
• heterocycles

A facile two-step synthesis of 2,4-dihydro-5-amino-[1,2,4]triazol-3-ones is described. Firstly, 1,3-disubstituted thioureas reacted with bis(trichloromethyl) carbonate (BTC) in the presence of a base such as NaHCO(3) to form the intermediate 4-(arylimino)-1,3-thiazetidin-2-ones almost quantitatively. Then the intermediates were treated with hydrazine monohydrate to give 2,4-dihydro-5-amino[1,2,4]triazol-3-ones in high yields. In the case of highly sterically hindered thioureas, carbodiimides were unexpectedly obtained in high yields under the same conditions.

• 出版日期2009-3-3
• 单位浙江工业大学