Kinetics of formation of 4-thiazolidinones by cyclocondensation reaction of Schiff bases and thioglycolic acid

Kinetics of formation of 4-thiazolidinone by cyclocondensation of Schiff ba ses (SB) and thioglycolic acid (TGA) have been studied. The reaction shows first order dependence both on SB and TGA concentrations; it follows an ove rall second order kinetics. The reaction is catalyzed by toluene-4-sulfonic acid (TSA). The influence of a neutral salt, namely, sodium perchlorate, d ielectric constant and temperature on the rate of reaction has been studied . Thermodynamic and kinetic parameters are evaluated. The order of reactivi ty of substituted SB is explained. A suitable mechanism is proposed. The ac tivation parameters are consistent with the proposed mechanism.