Facile synthesis of 3-aryl/alkylamino 5-aryl/alkyl 1,2,4-oxadiazoles from acylthiourea
摘要:
Facile and selective synthesis of 3-aryl/alkylamino 5-aryl/alkyl 1,2,4-oxadiazoles starting from N-acylthioureas has been demonstrated. The regio-selectivity is achieved by simply selecting an appropriate base used for the generation of hydroxyl amine from the corresponding hydrochloride salt. This method also avoids the use of toxic cyanogen bromide. The structure of the synthesized oxadiazoles has been resolved by tandem mass spectral studies. (C) 2011 Elsevier Ltd. All rights reserved.
Two new syntheses of 5-amino-1,2,4-oxadiazoles are described. The first one is based on the reaction of guanidine on benzhydroxamyl chloride. The second is more general and consists in allowing primary or secondary amines, hydrazine or guanidine to react with 5-trichloromethyloxadiazoles.
<i>N</i>-Halogen Compounds of Cyanamide Derivatives. VIII. A Convenient Method of Preparing 1,2,4-Oxadiazoles from<i>N</i>-Haloamidino Compounds
作者:Toshio Fuchigami、Keijiro Odo
DOI:10.1246/bcsj.49.3607
日期:1976.12
A new, efficient method for the preparation of 1,2,4-oxadiazoles from N-benzoylamidino compounds by treatment with t-butyl hypochlorite and sodium hydroxide has been devised. It was supposed that the ring formation proceeds via a nitrene intermediate.