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