Reactions of the (E)-O-arylbenzaldehyde oximes (1; Ar = 2,4-dinitrophenyl), (2; Ar =p-nitrophenyl), and (3; Ar = phenyl) with OH− in 60% aq. DMSO have been investigated. The eliminations are quantitative, producing only benzonitriles and aryloxides. The observation of second-order kinetics, k2OD-/k2OH-= 1.15-1.84, and βlg =-0.59 is consistent with an E2 mechanism. The Hammett ρ and k2OD-/k2OH- values increased with poorer leaving groups. For a given substrate the k2OD-/k2OH- value remained (within experimental error) roughly constant, in spite of changes in the β-aryl substituents. These changes in transition state parameters can be interpreted in terms of the differing nitrite-forming transition states involved.
|Number of pages||4|
|Journal||Journal of the Chemical Society. Perkin Transactions 2|
|Publication status||Published - 1989|
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