Role of intramolecular catalysis in the kinetics of Smiles' rearrangement of N-[2-(p-nitrophenoxy)ethyl]ethylenediamine

Abstract

Intramolecular displacement of alkoxide ion by the secondary amino group of N-[2-(p-nitrophenoxy)ethyl]ethylenediamine is not catalysed by general bases, but occurs by a specific base catalysed mechanism with a pH-insensitive rate plateau and approaches to a rate limit at high pH; the rate plateau at [OH^–]= 0·1–0·01 M is a consequence of the dominant catalytic effect of the neighbouring primary amino group in promoting rate determining deprotonation of the spiro-Meisenheimer intermediate.