反应详情

A prepared solution of trifluoromethyl ethane-magnesium bromide (made by refluxing Mg with 1-bromo, 2-trifluoromethyl ethane in THF for 2 hours; 4.6 g=25.82 mmol) in THF was added slowly to a cold (0° C.) solution of 3-bromo-N-methoxy-N-methylbenzamide (3.5 g, 14.3 mmol) in THF. The stirring continued at room temperature for 1 hour, quenched with cold saturated aqueous NH4Cl, acidified with 1 N HCl and extracted with ethyl ether. The organic extracts were combined, dried over MgSO4 and concentrated in vacuo. The crude product was purified on silica gel (ISCO) using hexanes/EtOAc (10/1) as the eluting solvent to give 1-(3-Bromo-phenyl)-4,4,4-trifluoro-butan-1-one as a colorless oil (3.1 g, 77% yield). m/e (M−H)− 279, 1H NMR (400 MHz, DMSO-d6) δ ppm, 2.5-2.6 (m, 2 H), 3.3-3.4 (m, 2 H), 7.5 (t, J=7.9 Hz, 1 H), 7.8-7.8 (m, 1 H), 7.9-8.0 (m, 1 H), 8.1 (t, J=1.7 Hz, 1 H).

1. customquenched with cold saturated aqueous NH4Cl
2. extractionextracted with ethyl ether
3. dry with materialdried over MgSO4
4. concentrationconcentrated in vacuo
5. customThe crude product was purified on silica gel (ISCO)