Isolation of the Intermediates and Improved Synthesis of Pyrido[1',2':1,2]imidazo[4,5-b]pyrazines and -quinoxalines
作者:Akira Katoh、Shuhei Ueda、Junko Ohkanda、Mutsumi Hirota、Hiroshi Komine、Keiryo Mitsuhashi
DOI:10.3987/com-92-6136
日期:——
2-(Pyrid-2'-yl)amino-3-chloro-5,6-dicyanopyrazines (IIa, IId, and IIe) and 2-(pyrid-2'-yl)amino-3-chloro-6-nitroquinoxalines (Va-c) were isolated for the first time in the course of the reaction of 2,3-dichloro-5,6-dicyanopyrazine (1) and 2,3-dichloro-6-nitroquinoxaline (IVa), respectively, with 2-aminopyridines. Furthermore, the yield of pyrido[1',2':1,2]imidazo[4,5-b]quinoxalines was remarkably improved due to the modification of the reaction conditions.