Boron tribromide → 3-Chloro-5-(4-hydroxyphenyl)isonicotinonitrile

Participants

Reaction Steps

A 1 M dichloromethane solution of boron tribromide (13.39 mL, 13.39 mmol) was added to a solution of 3-(4-(benzyloxy)phenyl)-5-chloroisonicotinonitrile (2.147 g, 6.69 mmol) in dichloromethane (20 mL) in a room temperature water bath. The orange suspension was stirred at room temperature for 40 min, poured to a stirred solution of saturated sodium bicarbonate (300 mL), diluted with dichloromethane (150 mL) and the mixture stirred overnight. The two phases were separated. The aqueous phase was extracted with dichloromethane (2×100 mL). The combined extracts were washed with saturated sodium bicarbonate (50 mL), water (2×50 mL), brine (50 mL), dried (MgSO4) and concentrated. The residue was diluted with methanol (10 mL), toluene (10 mL) and hexanes (30 mL), stirred for 1 h and filtered. The solid was rinsed with 1:3 mixture of toluene/hexanes to give 3-chloro-5-(4-hydroxyphenyl)isonicotinonitrile as tan solid (1.03 g, 65% yield). 1H NMR (400 MHz, methanol-d4) δ ppm 8.75 (1H, s), 8.71 (1H, s), 7.42-7.61 (2H, m), 6.87-7.05 (2H, m); MS (ES+) m/z: 231 (M+H); LC retention time: 3.223 min (analytical HPLC Method A).

Provenance & Evidence