Interaction of 3‐(2‐Aminophenyl)‐6‐R1‐1,2,4‐triazin‐5‐ones with Acylating Reagents: An Efficient Method for Preparation of 6‐Substituted 3‐R1‐2H‐[1,2,4]triazino[2,3‐c]quinazolin‐2‐ones

The series of 6-substituted 3-R1-2H-[1,2,4]triazino[2,3-c]quinazolin-2-one was prepared via condensation of 3-(2-aminophenyl)-6-R1-1,2,4-triazin-5-ones with acylating reagents. Particularities of 1H NMR spectra have been also discussed based on the comparison of experimental and theoretical results for 3-methyl-6-phenyl-2H-[1,2,4]triazino[2,3-c]quinazolin-2-one and its 4,3-isomer.