a method for producing maleimides . the method comprises reacting maleic anhydride and a primary amine at 100 - 180 ° c . in an organic solvent using a solid acidic catalyst , and purifying the maleimide produced therefrom by extraction and crystallization . the molar ratio of the primary amine to maleic anhydride is about 0 . 8 - 1 . 6 . with the present invention , high production yield with high purity of maleimides can be achieved . in addition , the solid acidic catalyst can be easily separated and recycled for subsequent use . thus , the present invention provides a number of distinct advantages , including substantially improved yield , conveniently reusable catalyst , reduced waste disposal and lower costs .