Boron tribromide → 1-(4-hydroxyphenyl)-1H-pyrazole-4-carbonitrile

Participants

Reaction Steps

To a solution of 1-(4-methoxyphenyl)-1H-pyrazole-4-carbonitrile (115 mg, 0.575 mmol) in dichloromethane (5 mL) was added boron tribromide (431 mg, 1.73 mmol) at −10° C. The reaction was then warmed to room temperature and stirred for 16 hours. The reaction was quenched with methanol (0.5 mL) and water (5 mL), and extracted with ethyl acetate (3×15 mL). The combined organics were washed with brine (15 mL), dried over sodium sulfate, filtered and concentrated to give 1-(4-hydroxyphenyl)-1H-pyrazole-4-carbonitrile (46 mg, 43%) as a yellow solid. 1H NMR (400 MHz, CDCl3, δ): 9.89 (s, 1H), 9.12 (s, 1H), 8.27 (s, 1H), 7.62 (d, J=9.2 Hz, 2H), 6.90 (d, J=9.2 Hz, 2H).

Provenance & Evidence