2-(4-Fluoro-phenoxy)-nicotinic acid (see reference Patent application WO 98/45268) (6.20 g, 26 mmol), 1-hydroxybenzotriazole (5.39 g, 40 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (6.62 g, 34 mmol) were disolved in N,N-dimethylformamide (50 ml) at room temperature and (4-aminomethyl-benzyl)-carbamic acid tert-butyl ester (6.28 g, 26 mmol) (see Preparation 1) added followed by addition of N-methyl morpholine (4.4 ml, 40 mmol). The reaction mixture was stirred under an atmosphere of nitrogen at room temperature for 18 hours, and then partitioned between ethyl acetate (100 ml) and water (100 ml) and the organic layer separated. The organic phase was then washed with a saturated aqueous solution of sodium chloride (100 ml), dried over anhydrous magnesium sulphate and the solvent removed in vacuo. The residue was triturated with diethylether (15 ml) giving [4-({[2-(4-fluoro-phenoxy)-pyridine-3-carbonyl]-amino}-methyl)-benzyl]-carbamic acid tert-butyl ester (9.52 g) as an off-white solid.
