Reaction Steps
A suspension of (4R)-tert-butyl 4-(6-(1-(tetrahydro-2H-pyran-2-yl)-5-(3,3,3-trifluoroprop-1-en-2-yl)-1H-indazol-3-yl)pyrazin-2-yloxy)-6-azaspiro[2.5]octane-6-carboxylate (100 mg, 0.167 mmol) and palladium on carbon (Aldrich, St. Louis, Mo.; 10% w/w; 17.75 mg, 0.017 mmol) in THF (2.0 mL) was cycled under a H2 atmosphere (1 atm; 3× evacuation/refill cycles) and stirred at 25° C. for 16 h. The mixture was filtered through Celite (washing with THF (3×5 mL) to quantitate the transfer) and the filtrate was concentrated in vacuo to provide (4R)-tert-butyl 4-(6-(1-(tetrahydro-2H-pyran-2-yl)-5-(1,1,1-trifluoropropan-2-yl)-1H-indazol-3-yl)pyrazin-2-yloxy)-6-azaspiro[2.5]octane-6-carboxylate (100 mg, 0.166 mmol, 100% yield; mixture of epimers at C1) as a white foam: 1H NMR (400 MHz, CDCl3) δ ppm 9.03 (1 H, s), 8.39 (1 H, br. s.), 8.20 (1 H, br. s.), 7.64 (1 H, t, J=4.3 Hz), 7.36 (1 H, d, J=8.4 Hz), 5.81 (1 H, d, J=7.2 Hz), 4.66 (1 H, br. s.), 4.41 (1 H, br. s.), 4.28 (1 H, br. s.), 4.03 (1 H, d, J=11.3 Hz), 3.78 (1 H, br. s.), 3.57 (1H, quin, J=8.1 Hz), 3.23 (1 H, d, J=12.5 Hz), 2.95 (1 H, br. s.), 2.57-2.71 (1 H, m), 2.49 (1 H, br. s.), 2.17-2.25 (1 H, m), 2.13 (1 H, br. d, J=12.5 Hz), 1.80 (2 H, d, J=7.4 Hz), 1.71 (1 H, br. s.), 1.58 (3 H, dd, J=7.0, 3.1 Hz), 1.12 (9 H, br. s.), 0.85 (1 H, d, J=12.7 Hz), 0.70 (1 H, br. s.), 0.56-0.62 (1 H, m), 0.54 (2 H, br. s.). 19F NMR (377 MHz, CDCl3) δ ppm −71.44 (3 F, d, J=8.0 Hz). MS (ESI, pos. ion) m/z: 602.3 (M+1).
