Boron tribromide → 2-Fluoro-4-[5-(methylsulfonyl)-2-pyridinyl]phenol

Participants

Reaction Steps

A solution of 2-{3-fluoro-4-[(phenylmethyl)oxy]phenyl}-5-(methylsulfonyl)pyridine (0.166 g, 0.46 mmol) in CH2Cl2 (20 mL) was cooled to −78° C. BBr3 (0.18 mL, 1.86 mmol) was added dropwise. The reaction mixture was stirred at −78° C. to 0° C. for 2 h, poured into ice and aqueous NaHCO3 and extracted with EtOAc (60 mL×2). The combined organic extract was washed with brine, dried over Na2SO4, filtered, and the filtrate was concentrated to give a solid, which was triturated with hot hexanes containing 1% of CH2Cl2 and 1% of MeOH to give 0.115 g (93%) of 2-fluoro-4-[5-(methylsulfonyl)-2-pyridinyl]phenol as a yellow solid. 1H NMR (400 MHz, CD3OD): δ 9.05 (d, 1H, J=2.4 Hz), 8.29 (dd, 1H, Ja=8.4 Hz, Jb=2.4 Hz), 8.03 (d, 1H, J=8.3 Hz), 7.92 (dd, 1H, Ja=12.6 Hz, Jb=2.2 Hz), 7.85-7.75 (m, 1H), 7.03 (t, 1H, J=8.6 Hz), 3.21 (s, 3H); LRMS (ESI), m/z 268 (M+H).

Provenance & Evidence