Hydrogen Bromide → 2-Bromo-1-(4-tert-butylphenyl)ethan-1-one

Reaction equation

[CH3:1][C:2]([C:4]1[CH:9]=[CH:8][C:7]([C:10]([CH3:13])([CH3:12])[CH3:11])=[CH:6][CH:5]=1)=[O:3].[Br:14]Br.Br>C(O)(=O)C>[Br:14][CH2:1][C:2]([C:4]1[CH:9]=[CH:8][C:7]([C:10]([CH3:13])([CH3:12])[CH3:11])=[CH:6][CH:5]=1)=[O:3]

Participants

Procedure

A solution of 4-tert-butylacetophenone (5 g, 28.4 mmol) in acetic acid (2 mL) was carefully (the reaction was exothermic) treated with Br2 (1.46 mL, 28.5 mmol), followed by 48% aq. HBr (0.015 mL, 0.132 mmol). The reaction was stirred at room temperature for 4 hours, then was poured onto ice and was extracted with diethyl ether. The organic phase was concentrated and was then chromatographed on silica gel, eluting with 5% ethyl acetate-hexane, followed by 10% ethyl acetate-hexane, to afford the title compound as a pale brown oil, 1.305 g (18%). 1H NMR (DMSO-d6) δ 7.94 (d, 2H, J=8.5 Hz), 7.58 (d, 2H, J=8.5 Hz), 4.90 (s, 2H), 1.31 (s, 9H); MS (ESI+) m/z 255 (M+H).