6.90 g (17.2 mmol) of 3-(4-methoxyphenyl)-2-oxo-2H-chromen-7-yl trifluoromethanesulfonate, 1.5 ml (25.4 mmol) of propyn-1-ol, 12.0 g (36.8 mmol) of caesium carbonate, 150 mg (0.578 mmol) of bis(acetonitrile)palladium(II) chloride and 800 mg (1.68 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl are left to stir at 60° C. for 3 h in 100 ml of dioxane, added to 400 ml of water and acidified using 2 N hydrochloric acid. The aqueous phase is extracted three times with ethyl acetate, and the combined org. phases are washed with water and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is filtered through silica gel with toluene/ethyl acetate (4:1). Crystallisation of the crude product from toluene/ethyl acetate (10:1) gives 7-(3-hydroxyprop-1-ynyl)-3-(4-methoxyphenyl)chromen-2-one as yellow crystals.
