Mechanistic chemistry of oxidation of balsalazide with acidic chloramine-​T and bromamine-​T: A comparative spectrophotometric kinetic study

Balsalazide (BSZ) belongs to a class of non-​steroidal anti-​inflammatory drugs. Kinetics and mechanism of oxidn. of BSZ with sodium N-​halo-​p-​toluenesulfonamides viz., chloramine-​T (CAT) and bromamine-​T (BAT) in HClO4 medium have been spectrophotometrically investigated (λmax = 357 nm) at 303 K. Under comparable exptl. conditions, reactions with both the oxidants follow a first-​order dependence of rate on [BSZ] and fractional-​order dependence on each [oxidant] and [HClO4]​. Activation parameters and reaction consts. have been computed. 2-​hydroxy-​5-​nitrosobenzoic acid and 3-​(4-​nitroso-​benzoylamino)​propionic acid are identified as the oxidn. products of BSZ with both CAT and BAT. The rate of oxidn. of BSZ is about five-​fold faster with BAT than with CAT. Plausible mechanism and related rate law have been deduced for the obsd. kinetics