Abstract: Reaction of 1,2-dicarbonyl compounds with ureas can serve as a convenient method of imidazolidine ring construction [1, 2]. The 4,5-dihydroxyimidazolidine-2-ones obtained as a result of this reaction are multifunctional compounds and can be used as starting material for preparation of various imidazole derivatives. For example, 4,5-dihydroxyimidazolidine-2-ones react with some nucleophiles to give 4,5- disubstituted imidazolidine-2-ones [2, 3]. The latter substances are of considerable interest owing to their useful properties. Some of these compounds have been found to be sedatives and hypnotics [4], tranquilizers [5], herbicides [6], steel corrosion inhibitors [7], cotton fabric modifiers [8], high-energy constituents of explosives [9], etc. Thus investigation of the reaction of 4,5-dihydroxyimidazolidine-2-ones with some new nucleophiles is very important from synthetic and practical points of view. In the present communication we report some results of our study on this reaction using arylsulfinic acids as nucleophiles.