Synthesis of polyamide containing optically active thymine derivative as a grafted pendant

Abstract
A new route to polyamides containing optically active thymine groups as pendants has been established. The method is based on the grafting of (–) and (±)‐2‐(thymin‐1‐yl)propionic acid [(–) and (±) TPA] onto a polyamide containing hydroxyl groups. The hydroxy polyamide was prepared by selective N‐acylation of an active diester of N‐hydroxy‐5‐norborene‐2,3‐dicarboxamide (HONB), N,N'‐(isophthaloyl‐dioxy)‐bis(5‐norbornene‐2,3‐dicarboximide) (IPBONB), with 1,3‐diamino‐2‐hydroxypropane (AHP). Model compounds (−) and (±)‐(1,3‐dibenzoylamino‐2‐propyl)2‐(thymin‐1‐yl)propionate[(−) and (±) (BAPTP)] were prepared by direct, low‐temperature esterification before synthesizing the polymer.