5-Bromo-2-hydroxybenzophenone → 4-Bromo-2-(hydroxy-phenyl-methyl)-phenol

Beteiligte Stoffe

Reaktionsschritte

1.02 g (27 mmol, 3.9 eqv) NaBH4 was added cautiously at rt to a solution of 1.92 g (6.9 mmol) (5-Bromo-2-hydroxy-phenyl)-phenyl-methanone (18) in 70 ml dry MeOH. After stirring this solution for 2 h at rt the solvent was evaporated and the residue was taken up in 70 ml water and 70 ml Et2O. The aq. layer was extracted with Et2O and the comb. org. fractions were washed twice with water, dried over Na2SO4 and evaporated. Column chromatography (Hexanes/EtOAc (1+1)) yielded 1.88 g (6.7 mmol, 98%) 19 as a white solid: Rf (Hexanes/EtOAc (1+1)) 0.57; mp 96-97° C.; 1H NMR (500 MHz, CDCl3) δ 2.76 (d, 1H, J=3.15 Hz), 5.98 (d, 1H, J=3.00 Hz), 6.79 (d, 1H, J=8.67 Hz), 6.98 (dd, 1H, J1=2.21 Hz, J2=0.47 Hz), 7.28 (dd, 1H, J1=8.67 Hz, J2=2.36 Hz), 7.33-7.41 (m, 5H), 7.92 (s, 1H); LRMS (EI) m/z 278 (5), 276 (4), 262 (56), 261 (100), 260 (46), 259 (95), 181 (21), 180 (12), 153 (12), 152 (33), 77 (16), 76 (16), 63 (10); HRMS (EI) Calcd. for C13H11BrO2: 277.994241. Found: 277.993366.

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