A General Synthesis of 3,5-Dihalo-2H-1,4-oxazin-2-ones from Cyanohydrins

Article abstract of DOI:10.1055/s-1990-27049

In a novel approach starting from O-trimethylsilyl protected or unprotected cyanohydrins and oxalyl chloride or bromide, a series of unknown 6-substituted 3,5-dihalo-2H-1,4-oxazin-2-ones were prepared.The method was shown to be efficient for various types of cyanohydrins; however cyclization was not obtained with cyanohydrins containing bulky substituents, electron-rich aryl or heteroaryl groups.A mechanism is proposed.