preparation of 2-bromo-5-cyanopyridine_industrial additives

preparation background and overview of 2-bromo-5-cyanopyridine

2-bromo-5-cyanopyridine, also known as 6-bromonicotinonitrile.

preparation of 2-bromo-5-cyanopyridine

synthesis of 6-bromonicotinonitrile.

method 1:

heat 6-chloronicotinonitrile (13.8 g, 100 mmol) in phosphorus tribromide (150 ml) at 145°c for 32 hours. after cooling, the mixture was concentrated in vacuo. phosphorus tribromide (150 ml) was added to the residue and the mixture was heated at 145°c for a further 32 hours. after cooling, the mixture was concentrated in vacuo and a mixture of ice and water (500 ml) was added. sodium bicarbonate was added to neutralize the mixture and the product was extracted with ethyl acetate (3×250 ml). the organic extracts were combined, washed with brine and dried over magnesium sulfate. the solvent was removed in vacuo and the residue was chromatographed (hexane-ethyl acetate) to obtain 14.9g (81%) 6-bromonicotinonitrile as a white solid: ¹hnmr (mhz, cdcl ₃)δ7.66(d,j=11.0hz, 1h),7.80(dd,j=3.1,11.0hz,1h),8.67 (d,j=3.1hz,1h); ms (m+h)⁺ m/z=183.0,185.0.

method 2:

liskey et al. reported that 2-bromopyridine-5-boronic acid was dissolved in methanol and water, and then mixed with cu(no₃)₂, zn(cn) _{2 mica}, react with csf by heating and stirring at 80°c for 2 hours to prepare 2-bromo-5-cyanopyridine, the yield can reach 61%.