Multicomponent Synthesis of Highly Substituted 2-Pyridones

A novel synthesis of polyfunctionalised pyridones, structurally related to cardiotonic agent milrinone is described. The procedure consists of an Ugi four-component reaction of 3-formyl-chromones, followed by a base-promoted ring-opening/ring-closing process. Variation of three of the four components in the Ugi reaction allows access to the final products with a combinatorial distribution of substituents.