화학공학소재연구정보센터
Journal of Electroanalytical Chemistry, Vol.423, No.1-2, 109-114, 1997
Reduction of Hydrazones of Aromatic Carbonyl-Compounds in Aprotic Media
Hydrazones of aromatic carbonyl compounds of the type ArRC=N-NR’R ", where R, R’ and R " are carbon substituents, are reduced in aprotic media to the radical anion, which may cleave to an amine anion and an imine radical; the reduction is analogous to the reduction of vinyl halides of the type ArR=CR’X. For R’ and R " equal to methyl the rate of cleavage is a linear function of the reversible reduction potential of the hydrazone. When R is hydrogen and R’ and R " are carbon substituents the base generated in the reduction (EGB) may induce an elimination of an amine with formation of a nitrile, when the leaving amine anion is a good leaving group; an analogous elimination to an acetylenic compound is found during the reduction of vinyl halides ArCH=CR’X. When R’ is hydrogen the hydrazone may be sufficiently acidic to protonate the radical anion (’father/son’ reaction); this is especially found when R " is an electron attracting group such as benzoyl. For phenylhydrazones, bases generated during the further reduction of the cleavage products may deprotonate the parent.