A mixture of (1-bromo-naphthalen-2-yloxy)-acetic acid tert-butyl ester (Intermediate 217, 125 mg; 0.37 mmol), 3-hydroxyphenylacetylene (53 mg; 0.44 mmol), palladium(II) chloride (3.3 mg; 0.02 mmol), triphenylphosphine (10 mg; 0.04 mmol) and piperidine (73 μl; 0.74 mmol) in distilled water (1.1 ml) and Acetone (1.4 ml) was stirred overnight at 60° C. The reaction mixture was extracted by EtOAc and the organic phases was dried over MgSO4, concentrated to dryness and purified by preparative HPLC. The intermediate obtained was diluted in DCM (1 ml) and treated with a 4 M solution of HCl in dioxane (930 μl). After stirring overnight, the reaction mixture was concentrated to dryness and purified by preparative HPLC to afford the title compound as a beige solid.
