Elimination reactions of (E)-2,4-dinitrobenzaldehyde O-aryloximes 1-3 promoted by EtO-, PhC(CH3)=NO-/PhC(CH3)=NOH, and CF3CH2O-/CF3CH3OH buffers in ethanol have been studied kinetically. The reactions produced 2,4-dinitrobenzonitrile and aryloxides as the only products. The observed second-order kinetics, Brønsted β= 0.55-0.75, |β1g| = 0.39-0.48 are consistent with the E2 mechanism. The Brønsted β decreased as the leaving group was made more nucleofugic and the |β1g| increased with a weaker base. The result can be described by a positive interaction coefficient, pxy = ∂β/∂pK1g = ∂β1g/∂pKBH > 0, which provides additional support for the E2 mechanism.
ASJC Scopus subject areas
- Organic Chemistry