反应详情

4-Fluorophenylhydrazine (15.5 g) and ethyl 2-ethoxymethyleneacetoacetate (22.9 g) synthesized according to the method described in J. Chem. Soc. Perkin trans. I, p. 1875, 1988 were stirred in ethanol (200 ml) at a refluxing temperature for 2 h. After the evaporation of the solvent, the residue was recrystallized from a mixed solvent of ethyl acetate-n-hexane to give ethyl 1-(4-fluorophenyl)-5-methylpyrazole-4-carboxylate (17.7 g), melting point: 48–49° C.

1. customAfter the evaporation of the solvent
2. customthe residue was recrystallized from a mixed solvent of ethyl acetate-n-hexane