Macrocyclic aramides (2n-aza[2n]paracyclophane-2n-ones): new intermediates for the synthesis of p-aramids

Abstract

An easy route to a new class of 2n-aza[2 n ]paracyclophane-2n-ones,N-substituted para-oriented cyclic aromatic amide (cycloaramid) oligomers, is described. The bulky diamine N,N'-di-sec-butyl-p-phenylenediamine is condensed with terephthaloyl chloride at elevated temperature in o-dichlorobenzene to provide a high yield of N,N'-di-sec-butyl-p-phenyleneterephalamide cyclic oligomers (from dimer to tridecamer). Ring opening polymerization of these new cycloaramides to high molecular weight linear polymers can be effected in the melt phase with highly nucleophilic catalysts.