Phosphorus tribromide → 6-Bromopyridine-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

6-Chloronicotinonitrile (13.8 g, 100 mmol) was heated at 145° C. in phosphorus tribromide (150 mL) for 32 h. After cooling, the mixture was concentrated in vacuo. To the residue was added phosphorus tribromide (150 mL), and the mixture was heated at 145° C. for another 32 h. After cooling, the mixture was concentrated in vacuo, and an ice-water mixture (500 mL) was added. Sodium bicarbonate was added to neutralize the mixture, and the product was extracted with ethyl acetate (3×250 mL). The combined organic extracts were washed with brine and dried over magnesium sulfate. The solvent was removed in vacuo, and the residue was chromatographed (hexanes-ethyl acetate) to give 14.9 g (81 %) of 6-bromonicotinonitrile as a white solid: 1H NMR (400 MHz, CDCl3) δ 7.66 (d, J=11.0 Hz, 1H), 7.80 (dd, J=3.1, 11.0 Hz, 1H), 8.67 (d, J=3.1 Hz, 1H); MS (M+H)+ m/z=183.0, 185.0.

Provenance & Evidence