| 摘要 |
PURPOSE:To prepare the titled compound useful as a radiation sensitizer for the radiotherapy of cancer, etc., with simple operation, without corrosion of the apparatus, suppressing the production of by-products, by reacting a specific uracil nucleoside with bromine in a wealky acidic solvent in the presence of basic ions. CONSTITUTION:5-Bromouracil nucleoside of formula III or formula IV can be prepared by (1) reacting uracil nucleoside of formulaI(R is H or OH) or formula II with bromine in a weakly acidic solvent (e.g. acetic acid) or a mixture of a weakly acidic solvent and other solvents in the presence of basic ions (e.g. sodium acetate) at room temp -60 deg.C, (2) after the completion of the reaction, distilling out the solvent from the reaction mixture under reduced pressure, (3) adding water to the residue, and separating the precipitated crystals, and (4) purifying the product by recrystallization. |
