反应详情

In analogy to the procedure described for example 4 b], (Z)-4-(4-fluoro-3-trifluoromethyl-phenyl)-2-hydroxy-4-oxo-but-2-enoic acid ethyl ester was reacted with methylhydrazine in ethanol under reflux conditions to give 5-(4-fluoro-3-trifluoromethyl-phenyl)-2-methyl-2H-pyrazole-3-carboxylic acid ethyl ester as colorless crystals and 5-(4-fluoro-3-trifluoromethyl-phenyl)-1-methyl-1H-pyrazole-3-carboxylic acid ethyl ester as colorless crystals.