The mechanisms of the anodic oxidation of a series of alkylbenzenes and alkoxybenzenes in dry acetonitrile are discussed. Electrochemical techniquen, assisted by analysis of the products, were used to determine the mechanisms. Modulated Specular Reflectance Spectroscopy was used to identify the major intermediates formed during the oxidation of the aromatic compounds. An ECE type of mechanism is proposed for the oxidation of both, the alkylbenzenes and the alkoxybenzenes, ltexaethylbenzene and 1,4Dimethoxybenzene are taken as examples to explain the mechanisms for the oxidation of alkyl and alkoxybenzenes, respectively. Reversible oxidation waves were observed in dry acetonitrile for either hexaethyl benzene and 1,4-dimethoxybenzene. All the other compounds oxidized irreversibly under the same conditions. Decay of the cation radical of the alkylbenzenes occurs due to a side chain proton loss, whilst radical cation from the alkoxybenzenes are attacked on the aromatic ring by the acetonitrile. In all cases, the formation of a nitrilium ion is suggested. For many of the compounds it was found that preparative electrolyses at constant potential were unsuccesful due to electrode fouling and very poor yields of products. A method of pulsed electrolysis was developed which, in conjunction with the presence of a cationic exchange resin, enabled a high yield of product to be obtained in a relatively clean reaction. This technique greatly extends the utility of the electrochemical method for the functionalization of aromatic compounds.