Zinc cyanide mediated direct α-cyanation of isonicotinic acid N-oxide. Application to the synthesis of FYX-051, a xanthine oxidoreductase inhibitor

Reaction of isonicotinic acid N-oxide 1a with dimethylcarbamoyl chloride and zinc cyanide in CH3CN at 120 °C gave the corresponding 2-cyanoisonicotinamide 2a in a good yield. This strategy was applied to the synthesis of FYX-051·TsOH 8, a xanthine oxidoreductase inhibitor.