An efficient method has been developed for the preparation of three novel heterocyclic compounds: Bridgehead-fused-5-methyl-6-methylketone-1,2,3-triazolo[5,1-c]-1,2,4-triazine(12), Bridgehead-fused-5-methoxyl -6- methylester-1,2,3-triazolo-[5,1-c]-1,2,4-triazine (14) and Bridgehead - fused - 5-methyl- 6-methylester-1,2,3-triazolo-[5,1-c] -1,2,4-triazine (16). The new heterocyclic systems were obtained utilizing 1H -1,2,3 – triazolo -5- diazonium salt (10) which was produced via thiourea sulphanilic acid(7). A mixture of this compound(7) with hydrazine in anhydrous acetonitrile, followed by continuous stirring afforded a solid compound: hydrazine carboximidamide (8). Addition of this hydrazine derivative to trimethyl orthoformate in a sealed vessel gave 5- amino – 1H- 1, 2,3 – triazole (9). Diazotization of this aminotriazole compound while maintaining the pH at 2, yielded the 1H – 1,2,3 – triazole -5- diazonium salt (10) in excellent yield.