Reaction of N-arylmaleimides with an equimolar amount of diethylamine, piperidine, and morpholine afforded the corresponding N-aryl-2-dialkylarninosuccininiides as mixtures of stereoisomers.
Reactions of equimolar amounts of o-, m-, and p-butoxyanilines with maleic anhydride give the corresponding N-butoxyphenylmaleamic acids which undergo cyclization into N-butoxyphenylmaleimides by the action of acetic anhydride in dimethylformamide in the presence of sodium acetate.