Dimethylformamide → 5-Bromo-2-hydroxybenzophenone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

10.07 ml (138.8 mmol, 2.2 eqv) SOCl2 was added to a solution of 14.77 g (63.9 mmol) 5-Bromo-2-methoxy-benzoic acid (17) in 140 ml dry toluene, followed by 0.5 ml (6.5 mmol, 0.1 eqv) DMF. After stirring this solution for 1.5 h at 70° C. the solvent was evaporated and the the crude acyl chloride was dissolved in 75 ml of dry benzene. This solution was then added cautiously under stirring to a suspension of 10.30 g (77.3 mmol, 1.2 eqv) AlCl3 in 80 ml dry benzene at 10° C. After complete addition the resulting mixture was refluxed for 5 h and then quenched by adding H2O and conc. hydrochloric acid. The aq. layer was extracted with EtOAc and the comb. org. fractions were dried over NaSO4 and evaporated. Column chromatography (CH2Cl2) yielded 16.03 g (57.9 mmol, 90%) 18 as a yellow solid: Rf (CH2Cl2) 0.67; 1H NMR (500 MHz, CDCl3) δ 6.99 (d, 1H, J=8.99 Hz), 7.52-7.68 (m, 6H), 7.70 (d, 1H, J=2.36 Hz), 11.91 (s, 1H); LRMS (EI) m/z 278 (80), 277 (100), 276 (86), 275 (92), 201 (31), 200 (22), 199 (30), 198 (20), 105 (63), 77 (57), 63 (19); HRMS (EI) Calcd. for C13H9BrO2: 275.978591. Found: 275.977717.

Herkunft & Nachweise