A new route to semirigid poly(amide‐ester)s with ordered structure

Four novel semirigid poly(amide‐ester)s having the same ordered amide‐amide‐ester‐ester (‐AAEE‐) and the same or the different phenyl structure were synthesized from the various combination of active acylamide of benzotriazole (HBT) such as 1,1′‐(isophthaloyl)bisbenzotriazole (IPBBT) and 1,1′‐(terephthaloyl)bisbenzotriazole (PBBT) with diols such as N,N'‐bis(2‐hydroxyethyl)isophthamide (HEIPA) and N,N'‐bis(2‐hydroxyethyl)terephthamide (HEPTA) which prepared from the selective N‐acylation of IPBBT or PBBT with aminoethanol in excellent yield at room temperature. Before the preparation of diol monomers, a model reaction of selective N‐acylation was also completed from active monoacylamide of benzotriazole, 1‐benzoylbenzotriazole with aminoethanol. The ordered structure of poly(amideester)s were characterized by infrared (IR) and NMR spectra. On the bases of different reactivity between selective N‐acylation and O‐acylation of active acylamide of benzotriazole, poly(amide‐ester)s having the ordered AAEE and the same phenyl structure were also readily synthesized from the IPBBT or PBBT with aminoethanol under mild conditions by one‐bath process.