Heterocyclization of Cyanoacetamide Derivatives: Synthesis and Biological Activity of Novel Azoles and Azines

The intermolecular cyclization of N -benzyl-2-cyanoacetamide with carbon disulfide followed by intramolecular cyclization gave thioxothiazinone 3 . This compound was used to synthesize a series of novel fused furopyrrole, pyridine, pyrimidine and other azine and azole derivatives. The Michael-type reaction of compound 3 with maleic anhydride followed by pyrrole and furan cyclizations and aromatization yielded polycyclic compound 7 . The [3+3]-cycloaddition of benzylidene malononitrile and its derivative to compound 3 gave pyridothiazines 10–12 . The ring opening in compound 3 under the action of urea or thiourea followed by pyrimidine cyclization and subsequent air oxidation resulted in the synthesis of oxa- and thiadiazolopyrimidinones 15 and 16 , respectively. The reaction of compound 3 with H 2 O 2 in a basic medium provided pyrimidine derivative 17 . The oxidation of compound 3 with Br 2 in an acid medium led to bromo derivative 19 . The synthesized novel compounds were characterized by elemental analysis and IR and 1 H and 13 C NMR spectroscopy and tested antibacterial and anticancer activities.