THERMOLYSIS OF 4-HETEROARYL SUBSTITUTED 5-AZIDO-1H-1,2,3-TRIAZOLES - COMPETITION BETWEEN REARRANGEMENT AND DECOMPOSITION

5-Azidotriazoles bearing a thiazole, benzothiazole or pyridine ring at the 4-position were synthesized and thermolyzed at 60-degrees-C. Wher eas the 5-azido-4-(thiazol-2-yl)triazole 4 decomposed with extrusion o f nitrogen and formation of the triazene 5 as the sole reaction produc t, the 5-azido-4-(benzothiazol-2-yl)triazoles 11a,b furnished mixtures of the triazenes 12a,b and tetrazoles 14a,b. In the case of the 5-azi do-4-(2-pyridyl)triazoles 17a-d, the product distribution was found to depend strongly on the N-1 aryl substituent, favouring the tetrazole 20 by increasing the electron-withdrawing capacity of this group.