5-(4-Chloro-phenyl)-4-ethyl-1H-pyrazole-3-carboxylic acid ethyl ester 、
碘甲烷 、
氢氧化钾 以to to give 5-(4-chloro-phenyl)-4-ethyl-2-methyl-2H-pyrazole-3-carboxylic acid ethyl ester as yellow crystals and 5-(4-chloro-phenyl)-4-ethyl-1-methyl-1H-pyrazole-3-carboxylic acid ethyl ester as yellow oil的产率得到5-(4-chloro-phenyl)-4-ethyl-2-methyl-2H-pyrazole-3-carboxylic acid ethyl ester