Thyroxine analogues: synthesis and nuclear magnetic resonance spectral studies of diphenylamines

Abstract

A series of N-benzoyl-2,6-di-iododiphenylamines have been prepared by the rearrangement of the benzimidates (Ia—b); the latter are easily obtained by the condensation of the 2,6-di-iodophenols with N-p-methoxyphenyl-benzimidoyl chloride. Preferential hydrolysis of the N-benzoyl group by potassium hydroxide helped in the synthesis of the compounds (IIIa—i). The method, however, failed with compounds (IVa—b) although the O-methyl group underwent hydrolysis with hydriodic acid.

N.m.r. analysis of the benzimidates and diphenylamines was performed. The phenomenon of the existence of pseudo cis- and trans-isomers about the C–N amide bond in N-benzoyl compounds is also discussed.