ONE-POT SYNTHESIS OF N-ALKYLATED 2-PYRIDONE DERIVATIVES UNDER MICROWAVE IRRADIATION

The pyridone derivatives are heterocyclic compounds with vital substructures of many naturally compounds [1] and medicines having a wide range of biological applications, such as antimalarial, antiasthma, vasodilatory, antiepilepsy, antimicrobial, antidiabetic, antiviral, and antioxidant activity, etc. [2]. Over the past decades, much attention has been focused on the synthesis of N-substituted pyridines [3]. The synthesis of N-alkyl-2(1H)-pyridones is feasible by the alkylation of 2-pyridones. In this case, selectively witching the reaction course is required to induce the N- or O-alkylation. In general, N-alkylation is performed via the sodium salt and O-alkylation via the silver salt, but a mixture of N- and O-alkylation was obtained in almost all cases [4-6]. However, there is still a need for more efficient approaches allowing the selective N-alkylation of 2-pyridones, as known procedures generally suffer from competition between N- and O-alkylation and/or low yields [7].

This work describes the synthesis of a series of N-alkylated 2-pyridone derivatives obtained from alkylation with different alkylating agents (Figure 1). The methodology developed is elaborated into the one-pot synthesis under the microwave, the compounds will be presented and discussed.