1-(3-bromo-2,4-dihydroxyphenyl)ethanone

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Stir 1-(3-bromo-2-hydroxy-4-methoxy-phenyl)-ethanone (20 g, 82 mmol) in dichloromethane (500 mL) at −30° C. under a nitrogen atmosphere. Treat with boron tribromide (30 mL, 318 mmol) and stir over night at room temperature. Pour mixture into cracked ice and stir for 1 hr. Extract twice with dichloromethane, wash organic layers with water, saturated aqueous sodium chloride solution, dry with magnesium sulfate, filter, and evaporate filtrate. Chromatograph residue on silica gel eluting with 2:1 dichloromethane/hexane to provide the title compound (13.8 g, 74% yield) as an off white powder. 1H NMR (CDCl3) δ 13.5 (s, 1H), 7.65 (d, J=8.0 Hz, 1H), 6.62 (d, J=8.0 Hz, 1H), 6.20 (s, 1H), 2.60 (s, 3H). Pour mixture into cracked ice stir for 1 hr Extract twice with dichloromethane wash organic layers with water, saturated aqueous sodium chloride solution dry with magnesium sulfate filter evaporate filtrate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Stir 1-(3-bromo-2-hydroxy-4-methoxy-phenyl)-ethanone (20 g, 82 mmol) in dichloromethane (500 mL) at −30° C. under a nitrogen atmosphere. Treat with boron tribromide (30 mL, 318 mmol) and stir over night at room temperature. Pour mixture into cracked ice and stir for 1 hr. Extract twice with dichloromethane, wash organic layers with water, saturated aqueous sodium chloride solution, dry with magnesium sulfate, filter, and evaporate filtrate. Chromatograph residue on silica gel eluting with 2:1 dichloromethane/hexane to provide the title compound (13.8 g, 74% yield) as an off white powder. 1H NMR (CDCl3) δ 13.5 (s, 1H), 7.65 (d, J=8.0 Hz, 1H), 6.62 (d, J=8.0 Hz, 1H), 6.20 (s, 1H), 2.60 (s, 3H). Pour mixture into cracked ice stir for 1 hr Extract twice with dichloromethane wash organic layers with water, saturated aqueous sodium chloride solution dry with magnesium sulfate filter evaporate filtrate