DFT Study of the Reaction Mechanism of N-(Carbomylcarbamothioyl) Benzamide.

The reaction mechanism for the formation of N-(carbomylcarbamothioyl)benzamide has been successfully computed with the B3LYP/6-31g(d) functional and basis set and compared with 1H NMR monitoring of the progress of the reaction with time. The reaction is proposed to proceed through two transition states: Ts1 (the rate-determining step) with highly unstable species (with a requisite orientation for the reaction to proceed), and Ts2 with a lower energy leading to the product. Computation of the reaction pathway was also carried out using the B3PW91/6-31G(d), M06/6-31G(d) and Wb97XD/6- 31G(d) functionals and basis set. These results do not present a clear reaction pathway compared to that given by the B3LYP/6-31G(d).