2-Fluorophenol → 5-(2-Fluoro-phenoxy)-2-(4-methoxy-3,5-dimethyl-phenyl)-oxazolo[5,4-d]pyrimidine

149 mg of sodium hydride were added under an argon atmosphere to a solution of 418 mg of 2-fluoro-phenol in 15 ml dimethylacetamide. After stirring for 30 min at room temperature a solution of 900 mg of 5-chloro-2-(4-methoxy-3,5-dimethyl-phenyl)-oxazolo[5,4-d]pyrimidine in 20 ml dimethylacetamide was added slowly. The mixture was allowed to stir for 1.5 h at room temperature. Upon consumption of the starting oxazolo[5,4-d]pyrimidine an aqueous solution of citric acid (100 g/l) was added until the pH was neutral. The aqueous layer was extracted twice with 15 ml of ethyl acetate. The combined organic layers were dried over sodium sulfate, filtered and the solvents were removed in vacuo. The title compound was isolated by silica gel chromatography (heptane/ethyl acetate gradient) as a white solid. Yield: 820 mg.