Abstract
Novel polyheterocyclic nitrogen systems such as 2-amino-1H-pyrazolo[5',1':3,4][1,2,4]-thazino[5,6-b]indole-3-carbonitrile 2, which has been synthesized for the first time in the present work, is considered as starting material for the synthesis of more novel polyheterocyclic systems with five fused rings and sometimes eight fused rings via heterocyclization with alpha,beta-bifunctional reagents under different conditions. The formed structures of the products were established from their correct elemental analysis and spectral data. Some of the compounds were evaluated for their antimicrobial activity using the Agar Well Diffusion method. Compounds 2, 4, 5, 6, 8 were found to be biologically active (Supplementary information).