A Practical Synthesis of N-aryl/N-alkyl 4-Pyridones under Continuous Flow Technology

In this report, a practical synthetic approach to access N-aryl/N-alkyl 4-pyridones via a two-step continuous flow process has been developed. In comparison to batch conditions, this [3+2+1] cycloaddition involving a three-components cascade reaction of aniline, dialkyl ethoxymethyl enemalonate and dialkyl acetylenedicarboxylate under mild conditions, which can provide N-aryl/N-alkyl 4-pyridone derivatives with a wider substrate scope and good to excellent yields.