To a solution of methyl 2-methyl-3-{5-[3-(2-pyridylamino)propoxy]indolyl}propanoate (0.015 g, 0.04 mmol), as prepared in the preceding step, in methanol (5.0 mL) was added a solution of NaOH (0.1 g, 2.5 mmol) in H2O (0.3 mL), and the reaction was stirred at ambient temperature overnight. After evaporating the solvent in vacuo, the residue is taken up in H2O (5 mL) and acidified to pH 4-5 with 10% HCl and extracted with ethyl acetate (2×15 ML). The combined organic layers were washed with brine, dried (Na2SO4), filtered and concentrated. The residue was purified by flash chromatography on silica gel (4% methanol in methylene chloride) to give the title compound as an oil (0.011 g, 80%). 1H-NMR (400 MHz, CDCl3) δ 7.86 (d, J=5.6 Hz, 1H), 7.50 (m, 1H), 7.26 (d, J=8.9 Hz, 1H), 7.07 (dd, J=13.1, 2.8 Hz, 2H), 6.84 (dd, J=8.9, 2.4 Hz, 1H), 6.56 (m, 2H), 6.32 (d, J=2.0 Hz, 1H), 4.38 (dd, J=14.3, 7.0 Hz, 1H), 4.07 (t, J=5.8 Hz, 2H), 4.01 (dd, J=14.3, 7.5 Hz, 1H), 3.44 (t, J=6.7 Hz, 2H), 2.92 (q, J=7.1 Hz, 1H), 2.08 (m, 2H), 1.12 (d, J=7.1 Hz, 3H). Mass spectrum (LCMS, ESI pos.) Calcd. for C20H23N3O3 354.3 (M+H); Found: 354.2.
