Dibromomethane → 1,3-Benzodioxole-4-carboxaldehyde

Participants

Reaction Steps

(a) A mixture of 2,3-dihydroxybenzaldehyde (6.4 g, 50 mmol) and sodium hydroxide (5 g in 25 ml of water) was added over 110 mins to a refluxing mixture of methylene bromide (17.3 g, 100 mmol), N,N,N-[tri-(C8 to C10 alkyl)]-N-methylammonium chloride (0.5 g; supplied by Aldrich Chemicals under the Trade Name "Adogen" 464) and water (10 ml). The mixture was heated at reflux for a further 5 hr under nitrogen and then steam distilled. The distillate was extracted with dichloromethane. Evaporation of the dried (MgSO4) organic extract gave 2,3-methylenedioxybenzaldehyde (3.2 g, 46%) as a yellow oil. Pmr spectrum (CDCl3 ; δ in ppm): 6.03 (2H,s); 6.66-6.99 (2H,m); 7.02-7.25 (1H,m); 9.97 (1H,s).

Provenance & Evidence