Studies of tertiary amine oxides. Part 13. Solvent effects on the rate of thermal rearrangement of N-(2,4-dinitrophenyl)piperidine N-oxide

Abstract

The rearrangement of N-(2,4-dinitrophenyl)piperidine N-oxide was studied in ten aprotic solvents. Different correlations of the first-order rate coefficients (k_obs.) with several solvent parameters were examined for the ten solvents with a range of 45 units in dielectric constant; the multiparameter equations of Krygowski and Fawcett, Koppel and Palm, and Kamlet and Taft were all examined. The k_obs. values were correlated reasonable well with the Lewis basicity of the solvent. Gutmann's donor number, and Dimroth's E_T(30) parameter when hydrogen-bond-donor solvents were excluded.