Heterocyclic Systems Containing Bridgehead Nitrogen Atom: Synthesis and Evaluation of Biological Activity of Imidazo[2,1-b]-1,3,4-thiadiazolo [2,3-c] -s-triazoles, s-Triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b]quinoxaline and bis-(s-Triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b][imidazo[4,5-b]-cyclohexane]-5a,6a-diene)

Condensation of 4-amino-5-mercapto-3-(alpha-naphthyl)-s-tnazole (1) with cyanogen bromide gives 6-amino-3-(alpha-naphthyl)-s-tnazolo[3,4-b]-1,3,4-thiadiazole (2) which on condensation with chloranil yields 3,9-di-(alpha-naphthyl)-6, 14-dioxo-bis-(s-triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b] imidazo[4,5-b]cyclohexane]-5a,6a-diene) (3) 3-(alpha-naphthyl)-s-tnazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b]quinoxaline (4) is obtained by a similar condensation of (2) with 2,3-dichloroquinoxaline The reaction of (2) with alpha-haloketones followed by bromination affords 7-aryl-3-(alpha-naphthyl)-imidazo[2,1-b]-1,3,4-thiadiazolo[2,3-c]-s-triazoles (5) and their 6-bromo analogues 6 respectively The structures of all newly synthesized compounds were established on the basis of elemental analyses, IR H-1-NMR The antibacterial and antifungal activities of all newly synthesized compounds have also been evaluated