The copolymerization of p-chlorophenylmaleimide (1) as electrophilic monomer with 2-methyl-2-oxazoline (2) as nucleophilic monomer without initiator in solution under different experimental conditions was investigated. Copolymers were characterized by FTIR and H-NMR spectroscopy. The copolymer composition was determined from H-1-NMR spectra. Molecular weights ranged between 1700 and 5400 g/mol by vapor pressure osmometry.