Synthesis and antibacterial studies of 6-aryl-2,2a-dihydro-naphtho-[2′,1′-5,6]pyrano[4,3-e][1,2,4]triazolo[3,4-b][1,3,4]thiadiazine and its derivatives

Synthesis and Antimicrobial Evaluation of Chiral 3, 5-Diaryl-5, 6-dihydrothiazolo[ 2, 3-c][1, 2, 4]triazoles

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Disclosed herein is a general approach for the synthesis of chiral thiazolo triazoles 5a-e. An efficient 3-step synthetic strategy has been developed to obtain the fused heterocycles in good yields. The key step involves formation of a secondary carbocation under acidic condition and intramolecular attack of the nitrogen of the 1,2,4-triazolo part leads to the formation of fused bicyclic compound in a regioselective manner. A new chiral center was created during the reaction and Chiral HPLC analyses confirmed the presence of the same and the racemic nature of the synthesized compounds. Their antimicrobial activities were evaluated by broth micro-dilution method and expressed as the minimum inhibitory concentration. The preliminary bioassay results demonstrate that most of the target compounds exhibit a significantly wide spectrum activity against S. aureus and E. coli comparable to ampicillin. The efficacies of compounds against C. albicans are either more or similar compared to Griseofulvin.