AMIDINES .8. A KINETIC-STUDY OF ALCOHOLYSIS OF N1-ARENESULFONYL-N1,N2-DIARYLACETAMIDINES

Alcoholysis of N1-arenesulfonyl-N1,N2-diarylacetamidines (1-30) was studied kinetically. The rate of the reaction between the substrates and ethoxide ion depended on the electron-withdrawing resonance effect of the substituents on both the N1-aryl and N2-aryl groups to a similar extent. The rate of the neutral alcoholysis depended on the resonance effect of the N1-aryl substituent to a larger extent than in the former reaction, and depended hardly at all on the electron-releasing resonance effect of the N2-aryl substituent, showing that the reaction does not proceed by the solvolysis mechanism. A reaction mechanism is proposed in which the rate-determining attack of the nucleophile is accompanied by the concerted departure of the N-arylarenesulfonamide group.