Synthesis and thermal rearrangement of tertiary amine oxides derived from substituted piperazine

N-Oxides are known to undergo three main thermal degradation reactions, namely deoxygenation, Cope elimination (for N-oxides containing a β-hydrogen) and Meisenheimer rearrangement. In this paper, we report a thermally induced oxygen migration from one N-oxide amine to another tert-amine group present in the same molecule through a six-membered ring transition state. The observed intramolecular oxygen migration resulted in the formation of a new isomeric N-oxide., In addition, we observed novel degradation behavior that happened after the Meisenheimer rearrangement of the newly formed N-oxide: a homolytic cleavage of the N O bond instead of elimination of an aldehyde or a ketone that usually follows the rearrangement. This communication deals with the synthesis, N, N-dioxidation and thermal rearrangement of N- para substituted phenyl N-methyl piperazine to the corresponding O-aryl hydroxylamine. Spectral data and kinetic measurements have been discussed and tabulated

Author(s): May S Saeed, Mohamed N Ibrahim, Mohamed E Elhag Ahmed

Abstract | PDF

Share This Article