To a solution of methyl 3-(5-{2-[6-(methylamino)-2-pyridyl]ethoxy}indolyl)propanoate (0.023 g, 0.65 mmol), as prepared in the preceding step, in methanol (3 mL) was added sodium hydroxide (0.15 g, 3.8 mmol) in H2O (0.5 mL) and the reaction was stirred for 6 hours at ambient temperature. After evaporating the solvent in vacuo, the residue is taken up in H2O (5 mL) and acidified to pH 4-5 with 10% HCl, extracted with a mixture of ethyl acetate and butanol (2×50 mL) and the combined organic layers were washed with brine, dried (Na2SO4), filtered and concentrated to give the title compound as a solid (0.018 g, 82%). 1H-NMR (400 M Hz, CDCl3+CD3OD) δ 7.52 (t, J=7.3 Hz, 1H), 7.25 (d, J=8.9 Hz, 1H), 7.14 (d, J=3.1 Hz, 1H), 7.06 (d, J=2.3 Hz, 1H), 6.81 (dd, J=8.9, 2.4 Hz, 1H), 6.60 (d, J=7.3 Hz, 1H), 6.38 (d, J=8.6 Hz, 1H), 6.33 (d, J=3.2 Hz, 1H), 4.38 (t, J=7.0 Hz, 2H), 4.24 (t, J=6.6 Hz, 2H), 3.06 (t, J=6.6 Hz, 2H), 2.89 (s, 3H), 2.77 (t, J=6.9 Hz, 2H). Mass spectrum (LCMS, ESI pos.) Calcd. for C19H21N3O3 340.3 (M+H); Found: 340.9.
