Oxidation of Borneol and Isoborneol by Pyridinium Chlorochromate and 4,4'-(N,N-Dimethylamino)pyridinium Chlorochromate-A Kinetic Study

Abstract

Oxidation of alcohols by a variety of oxidizing agents has attracted the attention of numerous workers owing to the commercial value of products. Extensive kinetic studies have been made on the oxidation of several organic substrates by oxidants like pyridinium chlorochromate, imidazolium dichromate, quinolinium chlorochromate and quinolinium fluorochromate by earlier workers. However, there are no reports so far on the kinetics of oxidation of bicyclic secondary alcohols with pyridinium chlorochromate and 4,4'-(N,N-dimethylamino)pyridinium chlorochromate (DMAPCC) which are mild efficient and practical reagents for oxidation reactions. In this present work pyridinium chlorochromate and DMAPCC were synthesized and purified. The results of the kinetics of the oxidation of borneol and isoborneol with pyridinium chlorochromate and DMAPCC in aqueous DMF (50 % v/v) medium in the presence of perchloric acid is reported. This current research work proposes the mechanism based on kinetics of oxidation of borneol and isoborneol. The kinetics of oxidation of borneol and isoborneol by pyridinium chlorochromate and 4-(N,N-dimethylamino) pyridinium chlorochromate in 50 % dimethylformamide solution was investigated. The influence of substrate, temperature, acid strength on the kinetics of the reaction and substrate in order of reaction was studied. The activation parameters such as DG^±, DH^± and DS^± were also determined.