139585-70-9

33252-28-7

139585-70-9

The general procedure for the synthesis of 2-bromo-5-cyanopyridine from 2-chloro-5-cyanopyridine is as follows: Example 29 Synthesis of 6-bromonicotinonitrile. 6-Chloronicotinonitrile (13.8 g, 100 mmol) was mixed with phosphorus tribromide (150 mL) and the reaction was heated at 145°C for 32 hours. After completion of the reaction, the mixture was cooled and concentrated in vacuum. To the concentrated residue, phosphorus tribromide (150 mL) was added again and the reaction was heated at 145°C for 32 hours. At the end of the reaction, the mixture was cooled and concentrated under vacuum. The concentrated residue was slowly added to an ice-water mixture (500 mL) and the reaction mixture was neutralized with sodium bicarbonate. Subsequently, the product was extracted with ethyl acetate (3 x 250 mL). The organic phases were combined, washed with saturated brine and dried with anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure and the residue was purified by column chromatography (eluent: hexane-ethyl acetate) to afford 14.9 g (81% yield) of 6-bromonicotinonitrile as a white solid. The product was characterized as follows: 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); mass spectra (M + H)+ m/z = 183.0, 185.0.