Nucleophilic Acyl Substitution of Acyl Diimides

(Figure Presented) The nucleophilic acyl substitution of the acyl diimide intermediate formed by the oxidation of isoniazid was found to involve two methanol molecules in a six-membered cyclic transition state. Calculations were performed in the gas phase at the B3LYP/6-311 + G(d,p)//B3LYP/6-31G(d) level of theory and solvation effects were included both explicitly and implicitly by using CPCM. The effect of electron withdrawing and donating groups on the aryl ring was also explored. The results obtained are in good agreement with experimental observations for the oxidation of isoniazid. © 2009 American Chemical Society.