KINETICS OF OXIDATION OF SOME SUBSTITUTED N,ALPHA-DIPHENYLNITRONES BYBROMAMINE-B IN ACID-MEDIUM

Kinetics of oxidation of N,alpha-diphenylnitrones by sodium N-bromobez enesulphonamide (BAB) in aqueous acetic acid containing perchloric aci d have been studied. The main products are benzaldehyde and nitrosoben zene. While each oxidation is first order each in [oxidant] and [subst rate], the rate is almost independent of [HClO4]. Variation of ionic s trength of the medium or addition of reduced product of the oxidant [B SA] has no or negligible effect on the rate of reaction. The solvent i sotope effect has been studied by using heavy water. The reaction has been studied for some meta- and para-substituted N,alpha-diphenylnitro nes at four temperatures, viz. 30, 35, 40 and 45 degrees and thermodyn amic parameters calculated. The validity of Hammett equation for the r eaction is tested. A probable mechanism has been proposed.