Method for preparation of 2-imino 4-oxo-5-phenyloxazolidine
AssigneeSKW Trostberg Aktiengesellschaft
InventorsStefan Weiss, Martina Lobensommer
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Abstract
A process for the preparation of 2-imino-4-oxo-5-phenyloxazolidine, which is used in medical applications under the name of pemolin, is described. The preparation proceeds by reacting at 10.degree. to 150.degree. C., optionally in the presence of a base catalyst, an aliphatic or an aromatic mandelic acid ester with an alkali or alkaline earth metal hydrogencyanamide, which can be prepared in situ; followed by treating the obtained reaction mixture or the metal salt isolated therefrom with a protonic acid, at temperatures from -30.degree. to 150.degree. C. until a pH value from 2 to 10 is reached.
Claims19
Process for the preparation of 2-imino-4-oxo-5-phenyloxazolidine of the formula:
- ##STR3## and/or its tautomeric forms, characterized in that a mandelic acid ester is treated with an alkali or alkaline earth metal hydrogencyanamide in a molar ratio of 1:2 to 1:0.5, at temperatures in the range of 10.degree. to 150.degree. C.;
- and in that thereafter the obtained reaction mixture metal salt is acidified to a PH value of 2 to 10, at temperatures from -30.degree. to 150.degree. C.
Dependencies are inferred from the claim text.