PROCESS FOR PREPARING SUBSTITUTED MALEIMIDES

The invention provides a process for the manufacture of substituted maleimides of the formula wherein R represents alkyl, aryl or heteroaryl and R represents hydrogen, alkyl, alkoxycarbonyl, aryl or heteroaryl, by reacting an activated glyoxylate of the formula wherein R has the above significance and X represents a leaving atom or group, with an imidate of the formula wherein R has the above significance, R represents alkyl, aryl or trialkylsilyl and Y represents oxygen or sulphur, in the presence of a base and, after treating a reaction product obtained in which R represents hydrogen or alkyl with a strong base, hydrolyzing and dehydrating the resulting hydroxy-pyrrolinone of the formula wherein R , R , R and Y have the above significance. The substituted maleimides of formula I are pharmacologoically active, for example as protein kinase C inhibitors useful e.g. in the treatment and prophylaxis of inflammatory, immunological, bronchopulmonary and cardiovascular disorders, or as antiproliferative agents useful e.g. in the treatment of immune diseases and allergic disorders.