Reaction Steps
(R)-tert-Butyl 4-((1-(3,5-dichloro-1H-indazol-7-yl)ethoxy)methyl)-4-(4-fluorophenyl)piperidine-1-carboxylate (4.6 g, 8.80 mmol) was dissolved in trifluoroacetic acid (20% in dichloromethane, 40 mL) and stirred at room temperature for 30 min. The reaction was concentrated and loaded onto a 20 g phenomenex strata giga tube strong cation exchange cartridge. After flushing the cartridge with several volumes of methanol (which were discarded), the product was eluted with 2M ammonia in methanol to give 3.75 g (100%) as a foam solid. 1H-NMR (CDCl3, 500 MHz) δ 9.88 (bs, 1H), 7.51 (d, J=1.1 Hz, 1H), 7.26 (dd, J=8.9, 5.5 Hz, 2H), 7.06 (dd, J=8.5, 8.5 Hz, 2H), 7.01 (d, J=1.1 Hz, 1H), 4.49 (q, J=6.4 Hz, 1H), 3.41 (d, J=8.9 Hz, 1H), 3.27 (d, J=8.9 Hz, 1H), 2.91 (m, 2H), 2.73 (m, 2H), 2.20 (m, 1H), 2.05 (m, 1H), 1.87 (m, 2H), 1.42 (d, J=6.6 Hz, 3H); 13C NMR (126 MHz, CDCl3) δ ppm 161.4 (d, J=246 Hz), 139.0, 136.9, 134.1, 128.5 (d, J=7.8 Hz), 128.3, 126.8, 125.2, 121.9, 117.7, 115.5 (d, J=21 Hz), 79.0, 77.9, 42.4, 42.3, 41.2, 33.5, 33.2, 22.0. Mass spec.: 328.12 (MH)+.
