According to von Braun1 the hydrogenation of a nitrile is expressed by the following series of reactions RCN + H, -> RCH=NH(1)RCH=NH + H, -»-RCHjNHj(2)RCH=NH + RCHjNH, -> RCH( NH,) NHCHjR ( 3) RCH( NH,) NHCH,R + H, ->-RCH,NHCH,R + NH, (4) Numerous procedures have been described in the literature to minimize the formation of secondary amines according to equations 3 and 4. Thus, Carothers8 hydrogenated benzonitrile to benzylamine with platinum oxide in good yields using acetic anhydride as solvent, and attributed the high yield to the fact that the primary amine is quickly acetylated and therefore protected against interaction with the intermediate imine. Hartung* used alcohol containing one mole of hydrochloric acid and palladized charcoal in the hydrogenation of aromatic nitriles, and Kindler4 used glacial acetic acid containing one mole of concentrated sulfuric acid and palladium sponge to hydrogenate nitriles to the corresponding ßarylethylamines. The high yield of primary amines in these reactions is attributed to the removal of the base from the reaction equilibrium by salt formation, thus preventing the possible interaction with the intermediary imine according to equation 3.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.