Reaction Steps
(±)-2-(2-Oxocyclohexyl)-5-{[4-(1H-pyrazol-1-yl)phenyl]methyl}-2,5-dihydro-3H-pyrazolo[4,3-c]quinolin-3-one (Example 720, 45 mg, 0.10 mmol) was dissolved in 1,2-dichloroethane (3 mL) and treated with acetic acid (0.029 mL, 0.51 mmol, 5 equiv) and methylamine (0.057 mL, 0.11 mmol, 1.1 equiv). After stirring for 20 minutes at ambient temperature, sodium triacetoxyborohydride (30 mg, 0.14 mmol, 1.4 equiv) was added and the mixture was vigorously stirred for 4 hours. The mixture was treated with methanol (1 mL), poured into water (15 mL) and extracted once with ethyl acetate (20 mL). The organic layer was discarded and the aqueous layer was treated with sodium bicarbonate (15 mL, aqueous saturated) and extracted with ethyl acetate (2×30 mL). The combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo, providing the titled compound: 1H-NMR (400 MHz, CDCl3) δ 8.45 (1H, s), 8.41-8.38 (1H, m), 7.89 (1H, d, J=2.5 Hz), 7.71 (1H, d, J=1.6 Hz), 7.70 (2H, d, J=8.5 Hz), 7.49-7.43 (2H, m), 7.41-7.38 (1H, m), 7.27 (2H, d, J=8.5 Hz), 6.47-6.46 (1H, m), 5.50 (1H, d, J=16.5 Hz), 5.44 (1H, d, J=16.5 Hz), 4.75 (1H, dt, J=10.5, 3.8 Hz), 3.02 (1H, m), 2.49-2.33 (1H, m), 2.37 (3H, s), 2.14-2.09 (1H, m), 1.98-1.92 (1H, m), 1.87-1.80 (1H, m), 1.70-1.59 (2H, m), 1.57-1.42 (2H, m) ppm; high resolution mass spectrometry (ES+) m/z 453.2387 [(M+H)+; calculated for C27H29N6O: 453.2397].
