A 50% aqueous solution of glyoxalate (67 mL, 0.61 mol) and tetrahydrofuran (130 mL) were added to a 250 mL round bottom flask and heated to reflux. A solution of N-benzylethanolamine (41.5 g, 0.27 mol) in tetrahydrofuran (20 mL) was slowly added dropwise under reflux conditions. After completion of the reaction, the tetrahydrofuran solvent was removed by rotary evaporator. Water (170 mL) was added to the residue, stirred and cooled to room temperature, followed by continued stirring in an ice water bath for 30 min to promote crystallization. The precipitated solid was collected by filtration and washed with ice water. The resulting pale yellow solid was dried to afford the target product 4-benzyl-2-hydroxy-morpholin-3-one (compound of formula VII, 51.8 g, 91% yield) with a melting point of 132-136 °C.
