Partially hydrogenated 2-amino[1,2,4]triazolo[1,5-a]pyrimidines as synthons for the preparation of polycondensed heterocycles: reaction with α-bromoketones
作者:Victor M. Chernyshev、Dmitry A. Pyatakov、Alexander V. Astakhov、Andrey N. Sokolov、Artem N. Fakhrutdinov、Victor B. Rybakov、Vladimir V. Chernyshev
DOI:10.1016/j.tet.2015.06.059
日期:2015.9
6-Ethoxycarbonyl-4,7-dihydro[1,2,4]triazolo[1,5-a]pyrimidines, which are resistant to oxidative aromatization, in analogous conditions with α-bromoketones produce bromides of 5,8-dihydro-1H-imidazo[2′,1′:3,4][1,2,4]triazolo[1,5-a]pyrimidines in one step. The unusual reaction of acid catalyzed hydrolytic cleavage of the imidazole ring of imidazo[2′,1′:3,4][1,2,4]triazolo[1,5-a]pyrimidines in the presence of hydrobromic
在α-3上用α-溴酮加热的2-氨基取代的4,5,6,7-四氢和4,7-二氢[1,2,4]三唑并[1,5- a ]嘧啶在N-3处进行选择性季铵化三唑并嘧啶核的原子,同时使二氢嘧啶环氧化芳构化。通过在乙醇溶液中加热碱,可以将季铵化的产物环化为咪唑并[2',1':3,4] [1,2,4]三唑并[1,5- a ]嘧啶。6-乙氧羰基-4,7-二氢[1,2,4]三唑并[1,5- a ]嘧啶具有抗氧化芳构化作用,在与α-溴酮类似的条件下,可生成5,8-二氢-1的溴化物。H-咪唑[2',1':3,4] [1,2,4]三唑[1,5- a一步合成嘧啶。在加热的条件下,在氢溴酸存在下,咪唑并[2',1':3,4] [1,2,4]三唑并[1,5- a ]嘧啶的酸催化水解裂解的异常反应是揭示了。通过实验和计算方法研究了部分氢化的咪唑并[2',1':3,4] [1,2,4]三唑并[1,5- a ]嘧啶的互变异构现象。