Water → 5-Bromovanillin

Participants

Reaction Steps

In a 250 mL round bottom flask vanillin (Aldrich, 33.3 g, 0.22 moles) was dissolved in glacial acetic acid (100 mL) with stirring. A solution of bromine (Baker, 35.0 g, 0.43 mol, 11.2 mL) in glacial acetic acid (100 mL) was added to the solution of vanillin. After 5 min a precipitate formed but the reaction was allowed to stir for an additional 15 min. The solid was collected by filtration giving 18.2 g, 35%. The filtrate was then slowly added to water (300 mL) and allowed to stand overnight. The resulting solid was filtered and dried under vacuum giving additional product (18.4 g, 35%, total yield 36.6 g, 70%), mp 159°-163° C. (lit, 163°-164° C.), 1H NMR (CDCl3) δ3.99 (s, 3H), 6.61 (bs, 1H), 7.36 (d, J=1.3 Hz, 1H), 7.64 (d, J=1.3 Hz, 1H), 9.79 (s, 1H).

Provenance & Evidence