The Efficient Electrochemical Reduction of Aliphatic Nitro Compounds to Amines in Neutral and Basic Media at Raney Nickel and Devarda Copper Electrodes

Abstract

The electrochemical reduction of aliphatic nitro compounds has been much less extensively studied than that of aromatic nitro compounds and the investigations have been carried out mainly in protic and acidic media. The preparative electrolytic reduction of primary and secondary nitroalkanes in dilute mineral acid containing alcohol at nickel, lead amalgam, and mercury cathodes gives the corresponding N-alkylhydroxylamines with high yields and good current efficiencies in a four-electron process. This chapter reports that aliphatic nitro compounds can be converted efficiently to amines in a neutral or basic medium by electro- chemical reduction in aqueous methanol at a Raney nickel or Devarda copper electrode. The resulting dihydroxylamine could either be hydrogenolyzed directly to the hydroxylamine or eliminate water (hydroxyl ion) to give the nitroso intermediate which would be reduced to the hydroxylamine.