4-Nitrobezoyl chloride (2) was reacted with isoeugenol in chloroform in the presence of triethyl amine and ester (4) was obtained in high yield. Ester (4) was reacted with SnCl2. 2H(2)O to give amine-ester (5), and subsequently was reacted with trimellitic anhydride (6) and novel isoeugenol ester-imide derivative (7), as a new monomer was obtained in quantitative yield. Compound (7) was characterized by high-field H-1-NMR, IR, and elemental analysis and then was used for the preparation of model compound (9) and polymerization reactions. 4-Phenyl-1,2,4-triazoline-3,5-dione (PhTD) (8) was allowed to react with compound (7). The reaction is very fast and gives only one double adduct (9) via Diels-Alder and ene pathways in excellent yield. The polymerization reactions of novel monomer (7) with bistriazolinediones [bis(p-3,5-dioxo-1,2,4-triazolin-4-ylphenyl)methane (10) and 1,6-bis(3,5-dioxo-1,2,4-triazolin-4-yl)hexane (11)] were carried out in N,N-dimethylacetamide (DMAc) at room temperature. The reactions are exothermic, fast, and gave novel heterocyclic polyimides (12) and (13) via repetitive Diels-Alder-ene polyaddition reactions. Some structural characterization and physical properties of these novel heterocyclic polyimides are reported.