Chemical kinetics:cyclisation reaction of hydrazinecarbothioamide,thioacetamide,and thiobenzamide with ethyl 2-bromoacetate

摘要

Substituted thiazolidine is formed from the cyclization reaction of hydrazine carbothioamide,thioacetamide,and thiobenzamide(thioamide)with ethyl 2-bromoacetate,and second-order reaction kinetics for both reactants are exhibited by the reaction,as determined by the Van't Hoff differential method.Thermodynamic parameter Energy of activation(Ea =65.1079 kJ/mol/K,54.54 kJ/mol/K,36.87 kJ/mol/K),enthalpy(ΔH#=60.1195 kJ/mol/K,49.56 kJ/mol/K,31.95 kJ/mol/K),entropy(ΔS# =-65.862 J/mol),Gibbs’free energy(ΔG# = 79.87k J/mol,76.72 k J/mol,76.56 k J/mol)and frequency factor(A = 2.77× 10~(+09),1.51×10~(+08),1.12× 10~(+05))was obtained by pH metric study of the reaction.According to the double-sphere mechanism,the distance between two atoms in solution with ethanol and isopropyl alcohol was calculated.