[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][CH2:9][OH:10])=[CH:4][CH:3]=1.[CH3:11][C:12]1[C:17]([CH3:18])=[CH:16][C:15]([CH3:19])=[CH:14][C:13]=1O.C(P(CCCC)CCCC)CCC>C1(C)C=CC=CC=1>[CH3:11][C:12]1[C:17]([CH3:18])=[CH:16][C:15]([CH3:19])=[CH:14][C:13]=1[O:10][CH2:9][CH2:8][C:5]1[CH:6]=[CH:7][C:2]([Br:1])=[CH:3][CH:4]=1A mixture of 2-(4-bromophenyl)ethanol (20.0 mL, 143 mmol), 2,3,5-trimethylphenol (31.1 g, 229 mmol), azodicarboxylic dipiperidide (72.1 g, 286 mmol) and tributylphosphine (88 mL; 357 mmol) in toluene (2.00 L) was heated to reflux for 2 h. The mixture was allowed to cool to rt. The mixture was filtered, washed with toluene and the solvents were partially removed under reduced pressure. The residue was diluted with Et2O and washed with aq. 1M NaOH (2×). The org. extracts were dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (petroleum ether→Et2O/petroleum ether 1:3) yielded the title compound (33.1 g, 73%). LC-MS: Rt=6.95.
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