PROCESS FOR PREPARING 1-SUBSTITUTED 5-HYDROXY-IMIDAZOLINE-2,4-DIONES AND 1-SUBSTITUTED 5-ALKOXY-IMIDAZOLINE-2,4-DIONES

摘要

A process for preparing specific 1-substituted 5-hydroxy-imidazoline-2,4- diones by reacting glyoxylic acid with N-substituted ureas is provided, where this process is carried out in a 10-80% strength aqueous solution and in the presence of an acid catalyst. The 1-substituted 5-hydroxy-imidazoline-2,4-diones can subsequentl y be converted in a further reaction step to give 1-substituted 5-alkoxy- imidazoline-2, 4-diones.