Hydrogenation of nitrobenzonitriles using Raney nickel catalyst

2-, 3-, 4-Nitrobenzonitriles were hydrogenated using Raney nickel catalyst in the environment of two different solvents (methanol and dioxane). The position of the nitro group relative to the nitrile group plays the dominant role in the course of hydrogenation. The nearer the substituent to the nitrile group is, the larger is its effect. 3- and 4-nitrobenzonitriles were hydrogenated to their primary amines, in contrast to 2-nitrobenzonitrile, which was transformedvia intramolecular oxidation to 2-aminobenzamide. During hydrogenation, numerous intermediates were formed. The choice of the solvent is another significant parameter affecting the course of hydrogenation.