Synthesis of some heterocycles of pharmaceutical interest

The condensation of 2-aminobenzimidazole (2), 3-amino-1,2,4-triazole (3), 5-aminotetrazole (4), 1-phenyl-3-aminopyrazolone (5), 2-aminobenzothiazole (6) and 2-amino-5-ethylthiadiazole (7) with 3-aryl-2,4-dicarboethoxy-5-hydroxy-5-methylcyclohexanones (1) has been investigated. Oxazepines 19 and 21 has been obtained from 1 and o-aminophenol. Cyclization of the carboxanilides 22 with polyphosphoric acid (PPA) gave the phenanthridinecarboxylates 23, while the cyclization of the arylhydrazones 26 gave the cinnoline carboxylate 27. The structures of the hitherto unknown ring systems have been confirmed by analytical and spectral methods. Some of the synthesized compounds were screened to test their antimicrobial and antifungal properties.