The efficient electrochemical reduction of nitrobenzene and azoxybenzene to aniline in neutral and basic aqueous methanolic solutions at devarda copper and raney nickel electrodes: electrocatalytic hydrogenolysis of NO and NN bonds

✍ Scribed by André Cyr; Pierre Huot; Gérard Belot; Jean Lessard

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 594 KB
• Volume: 35
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(90)85052-o

✦ Synopsis

The preparative electrochemical reduction of mtrobenzene, phenylhydroxylamme, azoxybenzene, azobenzene, and hydrazobenzene was studled under controlled potential con&ions at Devarda copper and Raney nickel electrodes m neutral (E= -0 6 V us see) and basic (E= -10 V us see) aqueous methanohc solutions The reduction of NB at Devarda copper electrodes was carried out also at constant current (-2 2 A dme2) m basic aqueous methanol The hfetlme of the Devarda copper electrode was about 21 days under these conditions In all cases, amhne was obtained m lugh chenucal (SS-100%) and current (SU-100%) yields, thus showing that hydrogenolysls of the N-O bond of phenylhydroxylatnme and of the N-N bond of hydrazobenzene 1s an efficient electrochenucal process at these electrodes An electrocatalytlc hydrogenation (ECH) mechanism IS most probably operatmg m this hydrogenolysis process For the reduction of mtrobenzene to phenylhydroxylamme and of azoxybenzene to hydrazobenzene, an ECH mechamsm and/or an electronatlon-protonatlon (EP) mechamsm can be mvolved