Selective functionalisation. Part 6. The chlorination of phenol in micellar solution

Abstract

The regioselectivity of chlorination of phenol by t-butyl hypochlorite in aqueous and methanolic sodium dodecyl sulphate (SDS) solution is shown to be related to the average orientation of the phenol molecule indicated by n.m.r. Studies. Thus ortho-chlorination is promoted in micellar solution but in reduced yield. When chlorination is mediated by a functionalised detergent containing a tertiary alcohol close to the head group, reaction occurs exclusively at the ortho-position. In contrast, a tertiary alcohol located remote from the head group mediates chlorination with a small increase in ortho-substitution. The results are discussed with respect to the design of selective functionalisation systems and the structure of micelles.