To tert-butyl 3-{2-[(3,5-bis-trifluoromethyl-benzyl)-(5′-isopropyl-4,5,2′-trimethoxy-biphenyl-2-ylmethyl)-amino]-pyrimidin-5-yloxy}-propionate (41 mg) is added a 4N-hydrochloric acid/dioxane (4 ml) and the mixture is stirred at room temperature for 9 hours. The reaction mixture is neutralized with a saturated aqueous sodium bicarbonate solution and the mixture is made weakly acidic with a 10% aqueous citric acid solution, and extracted with ethyl acetate. The organic layer is washed with a saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting residue is purified by silica gel column chromatography (hexane:ethyl acetate=4:1→1:3) and the resulting purified product is dissolved in ethanol (0.5 ml) and thereto is added 1M-aqueous sodium hydroxide solution (24 μl) and the mixture is concentrated under reduced pressure to give 3-{2-[(3,5-bis-trifluoromethyl-benzyl)-(5′-isopropyl-4,5,2′-trimethoxy-biphenyl-2-ylmethyl)-amino]-pyrimidin-5-yloxy}-propionic acid sodium salt (18 mg). MS (m/z): 706 [M−Na]−
