3-Hydroxybenzaldehyde → 2-Bromo-5-hydroxybenzaldehyde

Participants

Reaction Conditions

Reaction Steps

3-hydroxybenzaldehyde (10 g, 81.9 mmol) was dissolved in glacial acetic acid (50 mL) and cooled at 15° C. To the stirred solution, bromine (15.7 g, 98.2 mmol) was added dropwise while keeping the temperature below 22° C. After overnight stirring at room temperature, the volatiles were removed under vacuum without heating; the residue was co-evaporated three times with hexane (15 mL) and taken up in warm chloroform. Upon cooling, 9.05 g of 2-bromo-5-hydroxybenzaldehyde 3 were obtained as a white solid in two crops. Yield 55%. 1H NMR (300 MHz, CD3COCD3) δ ppm: 10.24 (s, 1H), 9.05 (s, 1H), 7.58 (d, J=8.7 Hz, 1H), 7.34 (d, J=3.1 Hz, 1H), 7.10 (dd, J1=8.7 Hz, J2=3.1 Hz, 1H); 13C NMR (75 MHz, CD3COCD3) δ ppm: 192.8, 159.3, 136.7, 136.2, 125.1, 117.3, 117.2; HRMS (EI) m/z: calcd for C7H5BrO2: 199.9472. found: 199.9463; mp: 132-134° C.

Provenance & Evidence