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