New optically active poly(ester‐imide)s derived from N,N′‐(4,4′‐carbonyldiphthaloyl)‐bis‐ L ‐phenylalanine diacid chloride

New optically active poly(ester‐imide)s containing benzophenone tetracarboxylic and L‐phenylalanine moieties were synthesized from N,N′(4,4′‐carbonyldiphthaloyl)‐Bis‐L‐phenylalanine diacid chloride (1) with several aromatic diols such as phenolphthalein (2a), hydroquinone (2b), 2,4‐dihydroxyacetophenone (2c), 1,8‐dihydroxyanthraquinone (2d), bisphenol‐A (2e), 1,5‐dihydroxynaphthalene (2f), 1,4‐dihydroxyanthraquinone (2g) and 4,4′‐dihydroxybiphenyl (2h) by low‐temperature solution polycondensation in CHCl3/Et3N solution. The polymerization reactions were started at 0°C and proceeded at room temperature, producing a series of optically active poly (ester‐imide)s with inherent viscosities of about 0.12–0.31 dL g−1. All of the above polymers are optically active and have been fully characterized by IR spectroscopy, elemental analyses, and specific rotation. Thermal properties of the poly(ester‐imide)s have been investigated using thermal gravimetric analysis.