反应详情

A mixture of ethyl 1-(4-phenoxybenzyl)-3-(4-phenoxybenzyloxy)-1H-pyrazole-4-carboxylate (21.50 g), 5% palladium-carbon (10.43 g) and tetrahydrofuran (300 ml) was stirred overnight under a hydrogen atmosphere. After the palladium-carbon was removed by filtration, the filtrate was concentrated to obtain ethyl 3-hydroxy-1-(4-phenoxybenzyl)-1H-pyrazole-4-carboxylate (13.35 g, yield 96%) as colorless crystals. This was recrystallized from acetone-hexane. Melting point: 117–118° C.

1. customAfter the palladium-carbon was removed by filtration
2. concentrationthe filtrate was concentrated