Three N-(4’-aminobenzoyl)lactams were prepared by condensation of 4-(sulfinylamino)benzoyl chloride with N-(trimethylsilyl)-3-dimethylazetidinone-2, N-(trimethylsilyl)pyrrolidone-2, and N-(trimethylsilyl)azepinone-2. The polycondensation of the N-(4-aminobenzoyl)lactams was studied in various reaction media, such as N-phenylpyrrolidone, diphenyl sulfone, m-terphenyl, or Marlotherm-S, at temperatures ranging from 180 to 400 degrees C. With regard to molecular weights, the best results were obtained in Marlotherm-S at 300 or 350 degrees C (eta(inh) similar to 1.5 dL/g). The ratio of polycondensation versus polyaddition (by ring opening) was determined by H-1 NMR spectroscopy. Up to 90% polycondensation was found for the beta-lactam derivative, along with side reactions limiting the molecular weight. The pyrrolidone- and epsilon-caprolactam-based monomers yielded copolyamides containing 80-95% 4-aminobenzoyl units. The WAXD powder patterns exhibit the typical reflections of semicrystalline poly(4-aminobenzamide) with little influence of the reaction conditions. The morphology of the polyamides was examined by SEM and TEM. Aggregates of crystallites looking like shavings were obtained at reaction temperatures greater than or equal to 275 degrees C.