Example 94
To a solution of tert-butyl 3-(1′-carbamoylspiro[chromane-2,4′-piperidine]-6-yl)indole-1-carboxylate (0.072 g, 0.16 mmol) in DCM (2 mL) was added hydrogen chloride (4 mol/L) in 1,4-dioxane (2.0 mL, 8.0 mmol) dropwise. The reaction was stirred overnight, concentrated, then dried under vacuum. Silica gel chromatography on the ISCO (0 to 100% (25% 20:1:1 EtOH:NH4OH:H2O—75% EtOAc)—100 to 0% hexanes; 40 g column) yielded the desired compound as an off-white solid (0.0330 g, 59%). Analysis: LCMS m/z=362 (M+1); 1H NMR (400 MHz, DMSO-d6) δ: 11.20 (d, J=1.5 Hz, 1H), 7.81 (d, J=8.0 Hz, 1H), 7.52 (d, J=2.5 Hz, 1H), 7.41 (d, J=8.0 Hz, 1H), 7.39-7.34 (m, 2H), 7.16-7.09 (m, 1H), 7.09-7.02 (m, 1H), 6.88-6.81 (m, 1H), 5.95 (s, 2H), 3.69 (d, J=13.3 Hz, 2H), 3.20-3.09 (m, 2H), 2.81 (t, J=6.7 Hz, 2H), 1.82 (t, J=6.8 Hz, 2H), 1.69 (d, J=13.6 Hz, 2H), 1.59-1.47 (m, 2H).
