HOBT (572 mg, 4.2 mmol), NMM (1.55 ml, 14.1 mmol) and EDAC.HCl (820 mg, 4.3 mmol) were added at 0° C. consecutively to a solution of 5-(5-ethyl-2,4-dihydroxy-phenyl)-4-(4-methoxyphenyl)-2H-pyrazole-3-carboxylic acid (500 mg, 1.4 mmol) in 40 ml of dry DCM. The resulting mixture was stirred at 0° C. for 15 minutes. Then a solution of N—BOC-1,3-diaminopropane (740 mg, 4.3 mmol) in 5 ml of dry DCM was added. The resulting mixture was stirred at 0° C. for one our and at room temperature for 2.5 hours. The reaction mixture was washed with 50 ml of 10% w/v aqueous citric acid solution, 50 ml 20% aqueous KHCO3 solution and 50 ml of distilled water. The organic extracts were dried over MgSO4 and evaporated under reduced pressure. The crude material was purified by automated column chromatography on a 40 g RediSep™ normal phase silica cartridge using an ISCO Companion™ eluting with a mixture of 5% methanol in DCM was used. The fractions containing the desired product were combined and evaporated under reduced pressure go give the title compound as a white solid (450 mg, 63%); 1H NMR Spectrum: δH (400 MHz, DMSO-d6) 0.90 (3H t, J=7.5 Hz), 1.38 (9H, s), 1.56 (2H t, J=6.9 Hz), 2.28 (2H q, J=7.4 Hz), 2.95 (2H d, J=6.1 Hz), 3.15-3.20 (2H, m), 3.72 (3H, s), 6.41 (1H, s), 6.57 (2H, s), 6.72 (1H, s br), 6.78 (2H d, J=7.3 Hz), 7.12-7.14 (2H, m), 7.92-8.02 (1H, m br), 9.28-9.35 (2H, m), 12.89 (1H, s, br);
