N-甲基哌嗪 、 4-Chloro-2-methyl-6-(4-phenyl-1-piperazinyl)-5-nitropyridine-3-carboxylic acid ethyl ester 以7-methyl-5-(4-phenyl-1piperazinyl)pyrido[3,4-b]pyrazine-8-carboxylic acid ethyl ester is formed的产率得到7-methyl-5-(4-phenyl-piperazin-1-yl)-pyrido[3,4-
b]pyrazine-8-carboxylic acid ethyl ester