Synthesis of triazolo[4,3-b][1,2,4,5]tetrazines and triazolo[3,4-b][1,3,4]thiadiazines using chitosan as ecofriendly catalyst under microwave irradiation

A novel approach to the synthesis of triazolo[4,3-b][1,2,4,5] tetrazines 5a-f and triazolo[3,4b][1,3,4]thiadiazines 10a-g has been developed via reactions of 4-amino-5-methyl-1,2,4-triazole-3(2H)-thione 1 with hydrazonoyl halides 2a-f and 8a-g, respectively using chitosan as a basic catalyst under microwave irradiation. The structure of the products was established based on elemental and spectral analyses. Further evidence for the assigned structure of the products is based on alternative synthesis. Also the mechanism of the studied reactions was discussed.