Preparation of new poly(amide–imide)s with chiral architectures via direct polyamidation reaction

N‐trimellitylimido‐L‐methionine (3) was prepared by reaction of trimellitic anhydride (1) with ‐L‐methionine (2) in acetic acid solution at refluxing temperature. This diacid was reacted with thionyl chloride, and N‐trimellitylimido‐L‐methionine diacid chloride (4) was obtained in quantitative yield. The resulting diacid chloride was reacted with p‐aminobenzoic acid in dry acetone and bis(p‐aminobenzoic acid)‐N‐trimellitylimido‐L‐methionine (5) was obtained as a novel optically active amide–imide diacid monomer in high yield. The direct polycondensation of amide–imide diacid monomer 5 with several aromatic diamines was carried out with tosyl chloride (TsCl)/pyridine (Py)/dimetheylformamide (DMF) system. The resulting thermally stable poly(amide–imide)s (PAIs) were obtained in good yields and inherent viscosities ranging between 0.24 and 0.46 dL g−1 and were characterized with FTIR, 1H NMR, CHN, and TGA techniques.