Abstract An efficient and simple synthesis of N-substituted 1, 3-oxazinan-2-ones was developed that involves a three-component, one-pot reaction of readily available tetraethylammonium bicarbonate, 1, 3-dibromopropane, and a primary amine in methanol at room temperature. l-Alanine can be used as the amino component to give the chiral product (2S)-2-(2-oxo-1, 3-oxazinan-3-yl) propanoic acid.