m-Chloroperbenzoic acid → 5-Bromo-2-methoxyphenol

Participants

Reaction Steps

5-Bromo-2-methoxy-phenol was synthesized by dissolving 5-bromo-2-methoxy-benzaldehyde (50 g, 233 mmol), in CH2Cl2 (150 mL) was cooled with an ice bath to 0° C., and subsequently, 3-chloroperoxybenzoic acid (70-75% purity) (68.1 g, 276 mmol) in CH2Cl2 (500 mL) was added. The reaction mixture was allowed to warm slowly to room temperature and stirred for 72 h. The colorless solid was filtered off, and the filtrate was stirred for 2 h with a 2 N Na2SO3 solution (200 mL). The organic layer was evaporated and the remainder dissolved in diethyl ether and washed with 1 N Na2SO3 and a half saturated NaHCO3 solution. The organic phase was extracted with a 2 N aqueous NaOH solution. The combined basic extract was acidified (pH ˜3-4) with concentrated HCl and then extracted with diethyl ether. The combined organic extracts were dried over MgSO4, filtered, and the solvent evaporated to afford intermediate 5-bromo-2-methoxy-phenol (43.5 g, 90%). 1H NMR (CDCl3) 7.06 (d, J=2.3, 1H), 6.96 (dd, J=8.6, 2.3, 1H), 6.70 (d, J=8.6, 1H), 5.67 (s, 1H), 3.86 (s, 3H).

Provenance & Evidence