Reaction Steps
To a suspension of 425 (78 mg, 0.12 mmol) in MeOH (3 mL) was added 1N NaOH (0.6 mL, 0.6 mmol). The reaction mixture was stirred at RT for 20 h. The reaction mixture was then concentrated, diluted with water and the pH was adjusted to 6-7 by addition of 1N HCl. To the resulting suspension was added MeOH to dissolve the mixture clearly, and purified via Biotage [KP-C18-HS 30 g, gradient 20-95% (methanol/water)]. Title compound 426 was obtained as a white solid (79.5 mg, 60% yield). 1H NMR (400 MHz, DMSO-d6) δ (ppm): one H of carboxylic acid is missing, 10.17 (brs, 1H), 8.53 (d, J=1.6 Hz, 1H), 8.51 (d, J=5.2 Hz, 1H), 8.29 (s, 1H), 8.20 (d, J=8.0 Hz, 1H), 8.02 (brs, 1H), 7.81 (dd, J=8.0, 2.0 Hz, 1H), 7.76 (dd, J=14.0, 2.4 Hz, 1H), 7.33 (t, J=9.0 Hz, 1H), 7.28 (dd, J=9.2, 2.0 Hz, 1H), 6.65 (d, J=4.4 Hz, 1H), 6.25 (d, J=7.6 Hz, 1H), 5.59 (t, J=3.6 Hz, 1H), 4.15-4.09 (m, 1H), 3.51 (s, 2H), 3.28 (d, J=4.4 Hz, 2H), 2.72-2.65 (m, 2H), 2.58-2.51 (m, 1H), 2.11-2.02 (m, 2H), 1.76-1.66 (m, 2H), 1.38-1.25 (m, 2H), 0.63-0.56 (m, 2H), 0.44-0.38 (m, 2H). MS (m/z): 634.5 (M+H).
