Synthesis of Substituted imidazo [1, 5-a] pyrimidine-2-(1H)-one Core Structure

Background and Objective: The objective of our work was to establish a facile and scalable synthesis of imidazopyridone for further use in medicinal chemistry applications. An easy synthesis of a core scaffold will enable the medicinal chemistry community to use imidazopyridone as a privileged scaffold in new chemical entity (NCE) synthesis. Materials and Methods: The synthesis was achieved from commercially available and cheap raw materials like amino acetonitrile hydrochloride or commercially available guanidine. Results: Simple transformation starting from amino acetonitrile hydrochloride leads to the synthesis of a versatile imidazo [1, 5-a] pyrimidine-2-(1H)-one core structure. Using suitable functionalized starting materials, a set of NCEs were synthesized to demonstrate the application of the developed synthetic scheme. Similarly, guanidine was also used to synthesize a regioisomer of imidazopyridone in moderate to good yields. Conclusion: We demonstrate the synthesis of two different regio-isomers of imidazopyrimidinone using simple chemical transformations. Its application in synthesizing NCEs has also been exhibited in the present work.