A DFT study on the effect of functional groups on the formation kinetics of 1,2,3-triazolo-1,4-benzoxazine via intramolecular 1,3-dipolar cycloaddition

A theoretical study of the kinetics and mechanism of the intramolecular cycloaddition of 1,2,3-triazolo-1,4-benzoxazine was performed using DFT methods at the B3LYP level of theory with 6-311++G(d,p) basis set at 298.15 K and 310.15 K. Equilibrium molecular geometries and harmonic vibrational frequencies of the reactant, transition state and product were calculated. The solvent effect on the kinetic and thermodynamic parameters of the reaction were investigated. The calculated rate constants and activation thermodynamic parameters showed good agreement with experimental results. These calculations indicated that the reaction proceeds through a synchronous concerted mechanism.