Nitrite → 2-Chloropyridine-3,5-dicarbonitrile

Participants

Reaction Conditions

Reaction Steps

Acetic acid (37 mL) was added over 10 min to sodium nitrite (13.4 g, 0.194 mol) with stirring. Concentrated sulfuric acid (12.3 mL) was added over 5 min to the resulting thick slurry which was then cooled to 0° C. In a separate flask, pyridinium hydrochloride (14.4 g, 0.125 mol) was added to a stirred mixture of 2-amino-3,5-dicyanopyridine (4.0 g, 27.75 mmol) in acetic acid (55 mL) and the resulting mixture was cooled to 0° C. to give a thick slurry. The nitrite slurry was added to the aminopyridine slurry over 5 min with stirring at 0° C. Acetic acid (50 mL) was added and the thick slurry was warmed to rt. After 1 h at rt the mixture was warmed to 50° C. and after a further 1 h, it was poured into an ice/water mixture (500 mL). The aqueous mixture was extracted with methylene chloride (4 times) and the combined extracts were dried (Na2SO4) and evaporated to a yellow solid. The crude product was purified by chromatography on silica (chloroform/methanol gradient, 1-3% methanol) to give the title compound as a solid:

Provenance & Evidence