Hydrochloric Acid → 3-Phenyl-3-{5-[2-(5,6,7,8-tetrahydro-[1,8]naphthyridin-2-yl)-ethoxy]-indol-1-yl}-propionic acid

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Reaction Steps

A solution of 3-phenyl-3-{5-[2-(5,6,7,8-tetrahydro-[1,8]naphthyridin-2-yl)-ethoxy]-indol-1-yl}-propionic acid ethyl ester (2.14 g, 4.49 mmol) in a 2:1:0.2 THF/MeOH/H2O (67 mL) was treated with lithium hydroxide monohydrate (0.38 g, 9.00 mmol) at room temperature. The reaction was stirred for 20 h. The mixture was diluted with ethyl acetate, acidified to pH 4 (0.5 N HCl), washed with water and brine, dried and concentrated to afford a crude mixture (2.02 g), which was purified by column chromatography with silica gel (39:1 to 29:1 dichloromethane/MeOH) to give the title compound (1.31 g, 66% yield). 1H NMR (CDCl3) 6 10.5 (s, 1H), 7.44 (d, 1H, J=3.1 Hz), 7.20–7.00 (m, 7H), 6.76 (m, 1H), 6.53 (dd, 1H, J=2.3, 6.6 Hz), 6.41 (s, 1H), 6.19 (d, 1H, J=7.3 Hz), 6.07 (dd, 1H, J=4.3, 7.1 Hz), 3.68 (m, 1H), 3.52 (m, 1H), 3.33 (m, 3H), 3.25–3.09 (m, 2H), 2.58 (m, 3H), 1.77 (m, 3H). Mass Spectrum (LCMS, ESI) calculated for C27H28N3O3 442.2 (M+H); found 442.3.

Provenance & Evidence