2-Bromo-3',4'-(methylenedioxy)propiophenone

Pale Yellow Solid

1-(benzo[d][1,3]dioxol-5-yl)-2-bromopropan-1-one (2-Bromo-3',4'-(methylenedioxy)propiophenone) can be used in the preparation of antifungal agents and MDMA analogs.

Bromine (10.0 mmol) was added to a solution of the ketone (10.0 mmol) in Et2O (25 mL). The solution was stirred for 30 min (until the color of the solution changed from red to light-yellow). Then, the reaction was quenched with water (10 mL), and the mixture was diluted with Et2O (25 mL). The organic layer was washed with a saturated solution of aqueous NaHCO3 (30 mL), a saturated solution of aqueous Na2S2O3 (30 mL), and brine (30 mL), and then it was dried over MgSO4, filtered, and concentrated. The α-bromoketone was purified by flash chromatography on silica gel. 2-Bromo-3',4'-(methylenedioxy)propiophenone [52190-28-0]. This compound was prepared according to the General Procedure from 3,4-methylenedioxypropiophenone (1.78 g, 10.0 mmol). The product was obtained as a white solid (eluted with 50% CH2Cl2 in hexanes; 2.13 g, 82% yield). 1H NMR (CDCl3, 500 MHz) δ 7.64 (d, J= 8.0 Hz, 1H), 7.49 (s, 1H), 6.87 (d, J= 8.0 Hz, 1H), 6.07 (s, 2H), 5.21 (q, J= 7.0 Hz, 1H), 1.88 (d, J= 7.0 Hz, 3H).