Reaction Steps
To a solution of 2-[4-(N-benzyloxycarbonylamino)-2-(5-methoxyindole-2-carboxamido)naphthalen-1-yl]ethyl acetate (0.5 g, 0.91 mmol) in methanol: tetrahydrofuran=1:1 (10 mL) was added potassium carbonate (0.13 g, 0.91 mmol) at room temperature and stirred overnight. The reaction mixture was diluted with AcOEt (100 mL) and washed with H2O (20 mL), saturated aqueous NaCl (20 mL), and then the organic layer was dried (Na2SO4) and concentrated under reduced pressure to yield as a brown foam 2-[4-(N-benzyloxycarbonylamino)-2-(5-methoxyindole-2-carboxamido)naphthalen-1-yl]ethanol (0.42 g, 94%): mp 198° C. (decomp.); 1H NMR (DMSO-d6, 500 MHz) δ 10.18 (s, 1H), 8.26 (d, 8.5, 1H), 7.97 (d, 8.5, 1H), 7.51 (t, 7.0, 1H), 7.43 (d, 8.5, 1H), 7.39 (d, 7.5, 2H), 7.33 (s, 1H), 7.31 (s, 1H), 7.28 (t, 7.5, 2H), 7.18 (t, 7.5, 1H), 7.11 (brs, 1H), 7.08 (d, 2.5, 1H), 6.91 (t, 6.0, 1H), 6.86 (dd, 9.0, 2.5, 1H), 6.81 (s, 1H), 5.35 (t, 4.5, 1H), 4.47 (d, 5.5, 2H), 3.76 (s, 3H), 3.69 (m, 2H), 3.11 (t, 6.0, 2H);); FABMS (NBA) m/z 465 (M−CO2+), IR (neat) νmax 3272, 2945, 2874, 1646, 1594, 1528, 1479, 1453, 1422, 1404, 1261, 1213, 1162, 1030, 841, 805, 758, 734, 699 cm−1.
