Mechanistic and Catalytic Behavior of Os(VIII) for the Chlorpheniramine Maleate and Bromamine-B Redox System: A Kinetics Based Approach

Authors

  • Nirmala Vaz Department of Chemistry, Jyoti Nivas College Autonomous, Bangalore-560095, India
  • N. Divya Department of Chemistry, Jyoti Nivas College Autonomous, Bangalore-560095, India
  • P. Nagaraja Department of Chemistry, University of Mysore, Manasagangothri, Mysore-570 006, India
  • A. S. Manjunatha Department of Chemistry, Bangalore University, Central College Campus, Bangalore-560001, India
  • Putta swamy Department of Chemistry, Bangalore University, Central College Campus, Bangalore-560001, India

Abstract

Chlorpheniramine maleate (CPM) is an important antihistamine agent. To the best of our knowledge there is no report in the literature about the oxidation of CPM with halogen + 1 oxidant from the stand point of its kinetics and mechanistic chemistry. Hence, a systematic kinetics and mechanistic study on the oxidation of CPM with bromamine-B (BAB) in the presence of NaOH and Os(VIII) catalyst has been carried out at 303 K. The reaction exhibits a first-order dependence of rate on [BAB]o and [Os(VIII)]. The order with respect to [CPM]o is zero, whereas it is fractional on [NaOH]. Activation parameters were evaluated. The stoichiometry of the reaction is 1:1 and the oxidation products were identified as (4-chlorophenyl)(pyridine-2-yl)methanol and 2-(dimethylamino)acetaldehyde from GC-MS analysis. The Os(VIII) catalyzed reaction is about four-fold faster than the uncatalyzed reaction. Based on the experimental results, possible reaction mechanism and kinetic model have been proposed.

 

Keywords: Chlorpheniramine maleate, Bromamine-B, Oxidation-kinetics, Os(VIII)
catalysis, mechanism

Published

2019-04-15

Issue

Section

Articles