Dimethylformamide → 7-Bromo-5-fluoro-3,4-dihydronaphthalen-1(2H)-one

Participants

Reaction Steps

To a solution of 4-(4-bromo-2-fluoro-phenyl)-butyric acid (0.625 g, 2.154 mmol) and DMF (0.0084 g, 0.108 mmol) in dichloromethane (10 mL) is added oxalyl chloride (0.558 g, 4.309 mmol). The mixture is stirred for 30 min and concentrated in vacuo at room temperature to give a yellow oil, which is re-dissolved in dichloromethane (20 mL) and added dropwise to aluminum chloride (0.402 g, 3.016 mmol) in dichloromethane (20 mL). The mixture is refluxed for 3.5 hours, and then poured into ice-water. The resulting mixture is extracted twice with diethyl ether. The organic phases are combined, washed with saturated aqueous NaHCO3, dried over MgSO4, filtered through a cotton plug, and concentrated. The resulting residue is purified by silica gel flash chromatography (hexanes-ethyl acetate, 19:1 to 9:1) to afford 7-bromo-5-fluoro-3,4-dihydro-2H-naphthalen-1-one; 1H NMR (400 MHz, CDCl3) δ ppm 2.13-2.19 (m, 2 H), 2.67 (t, J=6.6 Hz, 2 H), 2.90 (t, J=6.2 Hz, 2 H), 7.40 (dd, J=8.5, 1.9 Hz, 1 H), 7.98 (s, 1 H).

Provenance & Evidence