Heterocyclic systems containing bridgehead nitrogen atom: Synthesis, stereochemistry and evaluation of biological activity of thiazolo [3,2-b]-s-tetrazines and trans-dihydropyrazolo[3',4':4,5]thiazolo[3,2-b]-s-tetrazines

摘要

3,3-Diethyl-2H,4H-thiazolo[3,2-b]-s-tetrazin-6(7H)-one 2, 3,3-diethyl -2H,4H-6,7-dihydrothiazolo[3,2-b]-s-tetrazine hydrobromide 4 and 6-aryl-3, 3-diethyl-2H, 4H-thiazolo[3,2-b]-s-tetrazine hydrobromide 5 have been synthesised by the reaction of 6,6-diethyl-1, 2, 4, 5-tetrahydro-s-tetrazin-3-thione 1 with chloroacetic acid, 1,2-dibromoethane and #alpha#-haloketones, respectively. 7-Arylidene-3,3-diethyl-2H,4H-thiazolo[3,2-b]-s-tetrazin-6(7H) -ones 3 have been prepared either by the condensation of 2 with aldehyde or in a single step by the reaction of 1 with ethyl chloroacetate and aldehydes in the presence of pyridine and piperidine. Condensation of 3 with 2,4-dinitrophenylhydrazine in the presence of anhydrous sodium acetate furnishes 7,8-diaryl-2H,4H-trans-8,8a-dihydropyrazolo[3',4':4,5]thiazolo [3,2-b]-s-tetrazines 6. The antibacterial and antifungal activity of some of the compounds have also been evaluated.