An amine-ester derivative of isoeugenol was prepared in three steps. This amine-ester was converted to diazonium salt and subsequently was reacted with 2-naphthol and a novel isoeugenol ester-azo derivative as a new monomer was obtained in quantitative yield. This monomer was characterized by high-field H-1-NMR, IR, and elemental analysis and then was used for the preparation of model compound and polymerization reactions. 4-Phenyl-1,2,4-triazoline-3,5-dione was allowed to react with this new monomer. The reaction was very fast and gave only one double adduct by Diels-Alder and ene pathways in excellent yield. The polymerization reactions of novel monomer with bistriazolmediones [bis(p-3,5-dioxo-1,2,4-triazolin-4-ylphenyl)methane and 1,6-bis(3,5-dioxo-1,2,4-triazolin-4-yl)hexane] were carried out in N,N-dimethylacetamide at room temperature. The reactions were exothermic, fast, and gave novel heterocyclic polyimides by repetitive Diels-Alder-ene polyaddition reactions. Some structural characterization and physical properties of these novel heterocyclic polyimides are reported. (C) 2003 Wiley Periodicals, Inc.