Novel Method for the Synthesis of [1,2,4]Triazino[4,3‐c]quinazoline System

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

“…According to [4], we attempted to obtain 6-substituted 3-R 1 -2H- [1,2,4]triazino [2,3-c]quinazolin-2-one via condensation of 2-substituted-4-hydrazinoquinazolines with α-ketocarboxilic acid esters. Unfortunately, LC-MS data showed that refluxing of the mentioned compounds in acetic acid did not lead to the formation of the expected products.…”

“…Authors have found that the formation of the aforementioned substances proceeds through [4,3-с] systems intermediate resulted from specific Dimroth's type rearrangement. However, they obtained only 3-substituted 2H- [1,2,4]triazino [2,3-c]quinazolin-2-ones, despite the possibility of compound formation with substitutions in other positions that greatly expand their potential particularly as biologically active agents. Nevertheless, we synthesized an unexpected series of the 6-substituted compounds.…”

“…Nevertheless, we synthesized an unexpected series of the 6-substituted compounds. The main purpose of the presented investigation is the elaboration of preparative methods for 6-substituted 3-R 1 -2H- [1,2,4] triazino [2,3-c]quinazolin-2-ones.…”

“…The most common among the extensively discussed literature methods, which lead to the formation of such type of heterocyclic systems, is [4 + 2]-cyclocondensation [1][2][3]. Especial attention should be given to the series of publications [4,5] describing the formation of 3-R 1 -2H- [1,2,4] triazino [2,3-c]quinazolin-2-ones via condensation of 4-hydrazinoquinazoline with α-ketocarboxylic acid esters. Authors have found that the formation of the aforementioned substances proceeds through [4,3-с] systems intermediate resulted from specific Dimroth's type rearrangement.…”

“…Interaction of 3-(2-Aminophenyl)-6-R 1 -1,2,4-triazin-5-ones with Acylating Reagents: An Efficient Method for Preparation of 6-Substituted 3-R 1 -2H- [1,2,4]triazino [2,3-c] …”