A series of N-arylmaleimides (N-aryl-MI) and N-aryl-2,3-dimethylmaleimides (N-aryl-DiMeMI) were prepared by condensation of primary amines with maleic anhydride (MAn) and 2,3-dimethylmaleic anhydride (DiMeMAn), respectively. Preparation of N-aryl-MI proceeded through the formation of N-arylmaleamic acid, which subsequently cyclized to N-aryl-MI. In the reaction of N-arylamines with DiMeMAn, cyclic condensation products were formed in one step. By means of one- and two-dimensional 1H and 13C NMR spectroscopy it was proven that Naryl- DiMeMI and not isomaleimides were formed by a one step reaction
