A novel, efficient and mild KHSO4 mediatedsynthesis for 2-amino-1,3,4-oxadiazoles has been established via the cyclodesulfurization of benzoylhydrazine and isothiocyanate derivatives in one pot. The reactions proceeded smoothly at room temperature and produced corresponding products in moderate to good yields. This protocol also showed good functional group tolerance.
Synthesis of 2-amino-1,3,4-oxadiazoles from isoselenocyanates via cyclodeselenization
作者:Yuanyuan Xie、Junli Liu、Ping Yang、Xiangjun Shi、Jianjun Li
DOI:10.1016/j.tet.2011.05.100
日期:2011.7
An efficient one-pot method to access 2-amino-1,3,4-oxadiazoles from isoselenocyanates and hydrazides or dihydrazides was developed via cyclodeselenization. Without any harsh reagents, various 2-amino-1,3,4-oxadiazoles were obtained in considerably high yields (82%-97%) and purities (>99%) directly with simple crystallization in ethanol. And the formed precipitated Se powder during the reaction could be recycled for preparation of isoselenocyanates efficiently. A plausible mechanism is proposed for the formation of the target products. (C) 2011 Elsevier Ltd. All rights reserved.
Sharma, Laxmi Kant; Singh, Sushma; Siddiqui, Journal of the Indian Chemical Society, 2011, vol. 88, # 1, p. 155 - 161