Hydrazine hydrate (1:1) → Ethyl 5-(4-benzyloxyphenyl)-2H-pyrazole-3-carboxylate

Participants

Reaction Steps

A suspension of ethyl 4-benzyloxyphenyl-2,4-dioxobutanoate (35.86 g) in ethanol (300 mL) is treated with hydrazine hydrate (6 mL) and the mixture is heated at reflux for 2 hours. The reaction mixture is cooled to room temperature, filtered, and the solid washed with ethanol to give ethyl 5-(4-benzyloxyphenyl)-2H-pyrazole-3-carboxylate (25 g), m.p. 160-170° C.

Provenance & Evidence