PROCESS FOR PREPARING MEPHENOXALON

Mephenoxalone, i.e. 5-/(2-methoxyphenoxy)methyl/2-oxazolidon of formula I, is prepared by melting urea of formula II in a mixture with 3-(2-methoxyohenoxy)-1,2-propanediol of formula III in a quantity of 2.2 to 6 molar equivalents of urea of formula II to one molar equivalent of 3-(2-methoxyphenoxy)-1,2-propanediol of formula III, first at 170 to 210 degrees C and then at 240 to 260 degrees C, which leads to the thermal decomposition of the side reaction of the occurring N1, N3 - di/2-hydroxy3-(2-methoxyphenoxy)-propyl/biuret of formula IV and the subsequent share of the required 5-/(2-methoxyphenoxy)methyl/-2-oxazolidon of formula I. Further described is the method of extraction, purification and crystallisation of the raw product after the thermal reaction. Mephenoxalone is marked by its significant myorelaxation action and acts as a tranquilizer. It is used as an active substance in the production of pharmaceuticals.