Benzyl Bromide → 4-Benzyloxy-3-hydroxybenzaldehyde

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Reaction Steps

Benzyl bromide (9 mL, 0.073 mol, 1.05 eq) was added to a stirred solution of 3,4-dihydroxybenzaldehyde (10 g, 0.07 mol, 1 eq), tetra-n-butylammonium iodide (29.4 g, 0.077 mol, 1.1 eq) and cesium carbonate (24.8 g, 0.073 mol, 1.05 eq) in N,N-dimethylformamide (200 mL). The reaction mixture was stirred overnight, and then concentrated in vacuo. The residual solution was diluted with ethyl acetate (200 mL) and washed with water (2×200 mL). The organic solution was then extracted with 0.5M aqueous sodium hydroxide (5×200 mL), and the basic extracts combined and washed with ethyl acetate (400 mL), then acidified to pH 1 with concentrated HCl and back extracted with ethyl acetate (2×300 mL). The organic extracts were combined, washed with brine (200 mL), dried over sodium sulfate and evaporated in vacuo. This gave a gummy solid, which was recrystallized from ethyl acetate and petroleum ether to give the product as a brown powder (8.4 g, 51%). 1H NMR (CDCl3) δ 9.84 (s, 1H, O═C—H), 5.84 (s, 1H, OH), 5.21 (s, 2H, CH2Ph).

Provenance & Evidence