Synthesis of Five-Membered Heterocyles from Maleimides New heterocycles containing maleimide building blocks were prepared via 2-chloro-3-cyanomaleimide or 2,3-dichloromaleimides as key intermediates. Of the heterocyclic amines thus prepared, the following systems are useful as diazo components for preparing disperse dyes: 5-aminopyrazole-3,4-dicarboximides 5, 4-amino-5-alkoxycarbonylthiophene-2,3-dicarboximides 7, 5-aminoisothiazole-3,4-dicarboximides 9, 5-aminoisothiazole-3,4-dicarboxamide (10), 5-amino-3,4-dicyanoisothiazole (12), 5-amino-4-cyanothiophene-2,3-dicarboximides 15, and 2-aminothiazole-4, 5-dicarboximides 17.