N-Substituted 2,2,2-trifluoroethanimidic acid 1-methylethylidene hydrazides as synthetic blocks for trifluoromethylated nitrogen heterocycles: syntheses and oxidative cyclizations
作者:Kenji Uneyama、Kouji Sugimoto
DOI:10.1021/jo00048a042
日期:1992.10
N-Substituted 2,2,2-trifluoroethanimidic acid 1-methylethylidene hydrazides have been prepared and allowed to react with tert-butyl hypochlorite in CH2Cl2. N-Aryl-, N-alkyl-, and N-(methoxycarbonyl)amidrazones 2-4 undergo three types of cyclizations via the initially formed N-chloro intermediates leading to 3-(trifluoromethyl)-1,2,4-benzotriazines, 5, 3-(trifluoromethyl)-5-alkyltriazoles 8 and 9, and 3-chloro-3-(trifluoromethyl)-4-N-(methoxycarbonyl)-5,5-dimethyltriazoline (11), respectively. Reaction mechanisms for the cyclizations are discussed.