Micellar effects on heteroaromatic compounds. Part I. Nucleophilic substitution of 2-chloroquinoxaline with hydroxide ion

Abstract

The reaction between 2-chloroquinoxaline and hydroxide ion in water is catalysed by cationic micelles of hexadecyltrimethylammonium bromide (HTAB) and retarded by anionic micelles of sodium dodecyl sulphate (NaDS). The binding constants between substrate and micelles are 4200 for HTAB and 6200 for NaDS at 25°. Differences in micellar catalytic effects on nitroaromatic and ‘aza’ heteroaromatic substrates are discussed in terms of a difference in polarity between respective transition states.