A solution of Example 171b (0.110 g, 0.16 mmol) in 18 mL tetrahydrofuran/methanol (2:1) was treated with 1N lithium hydroxide (0.048 g, 2.00 mmol) in 2 mL water at room temperature for 4 hours. The material was diluted with ethyl acetate, washed with brine, dried over MgSO4, filtered, and concentrated. The residue was purified by trituration with diethyl ether/ethyl acetate and filtration to afford 15 mg of the title compound. 1H NMR (400 MHz, DMSO-d6) ppm 1.17-1.44 (m, 5H) 1.56-1.66 (m, 1H) 1.69-1.80 (m, 2H) 1.92-2.01 (m, 2H) 3.66-3.78 (m, 1H) 6.39 (d, J=7.63 Hz, 1H) 6.83 (d, J=6.71 Hz, 2H) 7.95 (s, 1H) 7.95-8.16 (m, 2H) 8.33 (s, 1H) 8.52 (s, 1H) 11.79 (s, 1H) 12.73 (s, 1H). MS (ESI+) m/z 393.7 (M+H)+.
