Catalytic hydration of cyanopyridines using nickel(0)

The homogeneous catalytic hydration of 2-, 3- and 4-cyanopyridines using 0.5 mol% of [(dippe)Ni(μ-H)]₂ as catalyst precursor was achieved under heating. In the case of 4-cyanopyridine, production of isonicotinamide was observed at temperatures in the range of 80-120 °C. Heating to 180 °C resulted in formation of isonicotinic acid. In the case of 2- and 3-cyanopyridines the quantitative formation of their corresponding amides was achieved at 100 °C. The catalytic hydration of 2,6-dicyanopyridine was also undertaken in this work, in its case resulting in the synthesis of the mixed cyano/amide product, 2-cyanopyridine-6-carboxamide, at short reaction times.