反应详情

A mixture of benzyl 3-benzyloxy-1-phenyl-1H-pyrazole-5-carboxylate (50.88 g), 1N aqueous sodium hydroxide solution (200 ml), tetrahydrofuran (200 ml) and ethanol (200 ml) was refluxed at room temperature for 5 hrs. 1N Hydrochloric acid (200 ml) was added and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4) and concentrated. The obtained colorless crystals were collected by filtration to give 3-benzyloxy-1-phenyl-1H-pyrazole-5-carboxylic acid (36.91 g, yield 95%), which was then recrystallized from acetone-isopropyl ether. melting point: 163–164° C.

1. extractionthe mixture was extracted with ethyl acetate
2. washThe ethyl acetate layer was washed with saturated brine
3. dry with materialdried (MgSO4)
4. concentrationconcentrated
5. filtrationThe obtained colorless crystals were collected by filtration