反应详情

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