Micellar Catalysed Autoxidation of Iso-Butanol, Amyl Alcohol and Iso-Amyl Alcohol by N-Bromobenzamide - A Kinetic Study

Asha Radhakrishnan, Parwinder Kair, L. V. Shastry and Brijesh Pare

A micellar catalyzed oxidation of iso-butanol, amyl alcohol and iso-amyl alcohol by N-bromobenzamide in acidic medium has been found to be two stage i.e. slow first stage followed by relatively faster second stage. The log (a-x) versus t curve displays an inflection. In both the stages the reaction follows first order behaviour with respect to each substrate and the oxidant, NBB. The cause of autocatalysis has been attributed to Br- ions. The removal of first stage on initial addition of potassium bromide further substantiated autocatalysis by bromide ions. The reactions have been found to be catalyzed by sodium dodecylsulfate. The effect of variation of sulfuric acid concentration is not substantial. The variation of solvent composition and addition of benzamide have also been studied. The thermodynamic parameters were computed by studying effects of temperature. The stoichiometry for the reaction is (R)2-CHOH + C6H5CONH3Br 2 (R)2-C=O + C6H5CONH2 + HBr On the basis of the various observations and product characterization most plausible mechanisms have been envisaged.

Inflection; micellar; autocatalysis; N-bromobenzamide