7-chloro-3-ethyl-5-methyl-3H-imidazo[4,5-b]pyridine-6-carboxylic acid ethyl ester 、
7-chloro-3,5-dimethyl-3H-imidazo[4,5-b]pyridine-6-carboxylic acid ethyl ester 以3,5-dimethyl-7-ethoxy-3H-imidazo[4,5-b]pyridine -6-carboxylic acid, ethyl ester is obtained的产率得到7-ethoxy-3,5-dimethyl-3
H-imidazo[4,5-
b]pyridine-6-carboxylic acid ethyl ester