Hydrochloric Acid → 1-(7-Bromo-3,3-dimethyl-2,3-dihydro-benzofuran-5-yl)-2-methyl-propan-1-one

Participants

Reaction Steps

To a solution of AlCl3 (1.5 g, 11.32 mmol) in dry dichloromethane (30 mL) was added dropwise at room temperature 1-(3,3-dimethyl-2,3-dihydro-benzofuran-5-yl)-2-methyl-propan-1-one (989 mg, 4.52 mmol) in dichloromethane (15 mL) followed by bromine (0.28 mL, 5.43 mmol) and the reaction stirred for 6 hours. 1N HCl was added slowly and the layers separated. The aqueous layer was extracted twice with dichloromethane. The combined organic layers were washed successively with aq. K2CO3, water and brine, dried over anhydrous magnesium sulfate, filtered and evaporated to give 1.44 g of 1-(7-bromo-3,3-dimethyl-2,3-dihydro-benzofuran-5-yl)-2-methyl-propan-1-one (91%). 1H NMR (300 MHz; CDCl3): δ 1.21 (d, J=6.9 Hz, 6H), 1.39 (s, 6H), 3.47 (m, 1H), 4.43 (s, 2H), 7.70 (s, 1H), 7.95 (s, 1H). e. 1-(3,3-dimethyl-2,3-dihydro-benzofuran-5-yl)-2-methyl-propan-1-one.

Provenance & Evidence