3-Amino-2(1H)-pyridinones from 1,3-Oxazolon-5-ones by a Multicomponent Reaction

Significance

Reported is the trans-selective, Lewis acid catalyzed synthesis of 3-amino-2(1H)-pyridinones via a three-component reaction of 2-phenyl-1,3-oxazolon-5-one, α,β-unsaturated ketones and primary amines. In order to increase the reactivity of the Ce(III) catalyst sodium iodide was added, which had the advantage of significantly increasing the diastereoselectivity. A plausible mechanism has been proposed as shown. Strong evidence for this mechanism is provided by the isolation of the Michael-addition adduct (A) in up to 76% yield when no amine is included in the reaction, and its conversion into the previously observed products on reaction with the relevant primary amine.