The amino substituted triazine ring was annelated to aminoazoles using a new effective synthetic procedure. The method of preparation involved initial formation of azolylformamidines in the reaction of aminoazoles with N,N-dimethylformamide dimethyl acetal followed by the triazine ring closure with cyanamide affording therefore fused aminotriazines.
Kalinin, D. V., Kalinina, S. A., & Dolzhenko, A. V. (2013). A new synthesis of amino substituted azolo[1,3,5]triazines via reaction of N1,N1-dimethyl-N2-azolylformamidines with cyanamide. Heterocycles, 87(1), 147 - 154. https://doi.org/10.3987/COM-12-12601