关键词: 自由基反应, 铁氰化钾, 氢氧化钾, 相转移催化, 苯偶氮化合物, 取代基效应, 反应机理

Using Galvinoxyl and potassium ferricyanide as catalyst, the oxidation of aromatic amines to symmetrical azobenzenes in a mixture of aqueous potassium hydroxide and dichloromethane is described for the first time in this paper. Close corelation between the rates and Hammett substituent constants is observed. The yields of products were also affected by substituents. The present work offers an efficient and rapid method for preparing azobenzenes. A possible mechanism is suggested as well.

Key words: FREE RADICAL REACTION, POTASSIUM FERRICYANIDE, POTASSIUM HYDROXIDE, PHASE TRANSFER CATALYSIS, BENZENE AZO COMPOUNDS, SUBSTITUENT EFFECT, REACTION MECHANISM