3-Hydroxybenzaldehyde → 2-Bromo-3-hydroxybenzaldehyde

Participants

Reaction Steps

The suspension of 3-hydroxybenzaldehyde (5 g, 0.04 mol), iron powder (172 mg, 3 mmol) and sodium acetate (6.72 g, 0.08 mol) in acetic acid (40 mL) was warmed until a clear solution was obtained and then cooled to room temperature. To this mixture was dropwise added a solution of bromine in glacial acetic acid (10 mL) over 15 min. After the addition, the reaction mixture was stirred for 2 h and then poured into ice-water. The resulting mixture was extracted with dichloromethane (3×50 mL). The combined extracts were dried over anhydrous Na2SO4 and concentrated. The residue was re-crystallized from dichloromethane to afford the product (2.3 g, yield 28%). 1H NMR (400 MHz, DMSO-d6 δ 10.30 (s, 1H), 7.54-7.51 (m, 1H), 7.39-7.35 (m, 1H), 7.31-7.27 (m, 1H), 5.90 (s, 1H).

Provenance & Evidence