FREMGANGSMAADE TIL FREMSTILLING AF OXAZOLIDIN-2,4-DIONER

1. A process for the preparation of oxazolidine-2,4-diones or the formula see diagramm : EP0056966,P6,F4 where R**1 is naphthyl, or phenyl which is unsubstituted or substituted by one or more halogen atoms, methyl or methoxy, R**2 is hydrogen, alkyl of 1 to 4 carbon atoms, halogen, vinyl, methoxymethyl or carboethoxy, and R**3 has the same meanings as R**2, R**2 and R**3 being identical or different, or R**2 and R**3 are bonded to one another and each is methylene, by reacting a hydroxycarboxylic acid amide with a diorganyl carbonate, wherein an amide of the formula see diagramm : EP0056966,P7,F1 where R**1, R**2 and R**3 have the above meanings, is reacted with a carbonic acid ester of the formula see diagramm : EP0056966,P7,F2 where R**4 is phenyl which is unsubstituted or substituted by methyl or halogen and R**5 has the same meaning as R**4, or R**4 and R**5 together are 1,2-phenylene, at from 50 to 250 degrees C, and the phenols R**4 OH and R**5 OH formed during the reaction are isolated, preferably by distillation.