Sodium hydroxide (0.2 mL of 1 N, 0.2 mmol) was added to a solution of the Methyl 13-cyclohexyl-6,7-dihydro-6-oxo -5H-indolo[2,1-a][2]benzazepine-10-carboxylate (20 mg, 0.052 mmol) in methanol (0.5 mL) and tetrahydrofuran (0.5 mL) in a microwave vial. The vial was sealed and the contents heated at 90° C. for 5 min in a microwave apparatus. The solution was acidified with dilute hydrochloric acid to precipitate the crude acid. The solid was collected and purified on the Shimadzu preparative liquid chromatograph. The product containing fraction was concentrated on a Speed Vac® to leave the titled compound as a white solid (18 mg, 92%). ESI-MS m/z 374 (MH+); 1H NMR (500 MHz, ACETONE-D6) δ 1.22–1.35 (m, 1 H) 1.41–1.58 (m, 2 H) 1.59–1.70 (m, 1 H) 1.73–1.85 (m, 2 H) 1.92–2.00 (m, 1 H) 2.11–2.26 (m, 3 H) 3.04 (m, 1 H) 3.60 (d, J=14.04 Hz, 1 H) 3.97 (d, J=13.73 Hz, 1 H) 4.56 (d, J=18.31 Hz, 1 H) 5.19 (d, J=18.31 Hz, 1 H) 7.51 (m, 2 H) 7.57 (t, J=7.32 Hz, 1 H) 7.66 (d, J=7.63 Hz, 1 H) 7.81 (dd, J=8.39, 1.37 Hz, 1 H) 8.03 (d, J=8.24 Hz, 1 H) 8.23 (s, 3 H).
