6-Bromovanillin

881-68-5

60632-40-8

The general procedure for the synthesis of 2-bromo-4-hydroxy-5-methoxybenzaldehyde from acetylvanillin is as follows: 1. 4-Formyl-2-methoxyphenyl acetate (5.00 g) and bromine (1.42 mL) were added to an aqueous solution (120 mL) of potassium bromide (10.3 g) and the mixture was stirred at room temperature for 8 hours. 2. The precipitate was collected by filtration and washed with water. 3. 6N hydrochloric acid (120 mL) was added to the resulting solid and the mixture was stirred at 90 °C for 16 hours. 4. The precipitate was collected by filtration and washed with saturated aqueous sodium bicarbonate and water. 5. The solid obtained was dissolved in ethyl acetate and the mixture was filtered through silica gel to give the title compound as a light yellow solid (yield: 4.88 g). 6. The resulting solid was recrystallized from ethyl acetate/n-heptane to give the title compound as a light yellow solid (yield: 3.98 g, 68%). 1H-NMR (DMSO-d6, 300 MHz): δ 3.83 (3H, s), 7.11 (1H, s), 7.34 (1H, s), 10.01 (1H, s), 10.86 (1H, br s).