Hydrazine hydrate (1:1) → methyl 3-phenyl-1H-pyrazole-5-carboxylate

Participants

Reaction Steps

To a solution of 2-hydroxy-4-oxo-4-phenyl-but-2-enoic acid methyl ester (12.0 g, 58.2 mmol) in EtOH (30 ml) was added hydrazine monohydrate (2.84 mL, 58.2 mmol) and the mixture was heated at reflux for 5 h. The reaction mixture was cooled to room temperature and filtered in vacuo. The precipitate was washed with EtOH to give the desired product (6.02 g, 51.5% yield): MS (EI) for C11H10N2O2: 203.08 (MH+).

Provenance & Evidence