2,5-Dichloro-3-nitropyridine → 3-Amino-2,5-dichloropyridine

Participants

Reaction Steps

26.0 g of Raney nickel catalyst are washed with ethanol and then added to a solution of 129.2 g (0.69 mol) of 2,5-dichloro-3-nitropyridine in 1300 ml of dioxane. This mixture is hydrogenated with hydrogen under normal pressure and at a temperature in the range from 20° to 35° C. After reaction of 20% of the required amount of hydrogen, a further 30.0 g of Raney nickel catalyst are added to the reaction mixture. After a hydrogenation period of 22 hours, the catalyst is removed, the solvent is evaporated off and the residue is crystallised from ethyl acetate/hexane, affording 84.9 g (78% of theory) of 3-amino-2,5-dichloropyridine, m.p. 129°-132° C.

Provenance & Evidence