Patent ID: 7235666
Filing Date: 2007-06-26
Classification: C07F

Abstract:
1. A process for the preparation of phosphoric acid diester 2,5-dioxo-4,4-diphenylimidazolidin-1-ylmethyl esters, wherein 3-(hydroxymethyl)-5,5-diphenylimidazolidine-2,4-dione is converted to an alkylsulfonate or arylsulfonate and this is reacted with a phosphoric acid diester whose ester groups can be selectively cleaved from the reaction product, wherein the alkylsulfonation or arylsulfonation of said 3-hydroxymethyl-5,5-diphenyl-imidazolidine-2,4-dione and the reaction of said alkylsulfonylation or arylsulfonylation product with said phosphoric acid diester is carried out in the presence of trisubstituted aliphatic amine base, at a temperature of −10° C. to +30° C. and in the presence of polar aprotic solvent, said solvent being selected from the group consisting of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethylimidazolidin-2-one, 1-methylpyrrolidin-2-one and dichloromethane.