REDUCTIVE HYDROLYSIS OF NITRILES TO ALDEHYDES BY PRECIPITATED NICKEL ON IRON OR ALUMINUM

The reductive hydrolysis of nitriles to the corresponding aldehydes has been studied under the conditions of dissolving metal reduction. A dissolving metal (Al or Fe) covered with a promoter metal (Ni) by cementation has been applied as a reducing agent. The dissolution of Al or Fe supplies electrons for the nitrile hydrogenation, which takes place on the Ni surface. The presence of Ni increases the aldehyde yield by a factor of 4-40. The bimetallic systems have unusually high stability, remaining active even in hot, aqueous acidic medium. The variables of cementation have been found to greatly influence the particle size and morphology of the bimetallic system and the yield of aldehyde formation in the reductive hydrolysis of benzonitrile. After optimising the reaction variables, both aromatic and aliphatic nitriles were reduced to aldehydes with 69-95% yield.