Chemical synthesis of 1,4-oxazin-2-ones

摘要

The present invention relates to a process for the preparation of a compound of formula (I): wherein R1 is a C1-6alkyl or arylC1-4alkyl group; and R2 is a hydrogen atom, a halogen atom, or a group selected from C1-6alkyl, CF3or C1-6alkoxy substituted by C1-4alkoxy; which comprises reacting an anhydrous or hydrated glyoxal of formula (II) with a compound of formula (III): in the presence of an acid.