反应详情

A mixture of methyl 3-benzyloxy-1-phenyl-1H-pyrazole-5-carboxylate (15.00 g), 5% palladium on carbon (10.92 g) and tetrahydrofuran (200 mL) was stirred under a hydrogen atmosphere at room temperature for 1 hr. After removing palladium on carbon by filtration, the mother liquid was concentrated. The residue was subjected to silica gel column chromatography to give methyl 3-hydroxy-1-phenyl-1H-pyrazole-5-carboxylate (10.30 g, yield 97%) as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:2, v/v). The crystals were recrystallized from tetrahydrofuran-isopropyl ether. melting point: 227-228° C.

1. customAfter removing palladium on carbon
2. filtrationby filtration
3. concentrationthe mother liquid was concentrated