Reaction Steps
To a solution of 4-(3-amino-6-((1S,3S,4S)-3-fluoro-4-hydroxycyclohexyl)pyrazin-2-yl)-2-fluorobenzoic acid (3927 mg, 9.3 mmol) in NMP (Volume: 60 mL) was added (S)-2-amino-2-(3-fluoro-5-iodophenyl)ethyl di-tert-butyl phosphate (4740 mg, 9.30 mmol), DIEA (9.75 mL, 55.8 mmol), and then HATU (5304 mg, 13.95 mmol). The reaction mixture was stirred at room temperature for 2 hours followed by LCMS. To the crude reaction was added 850 ml of ethyl acetate washed with saturated bicarbonate (2×), water (3×), saturated salt solution, dried sodium sulfate, filtered and dried to residue. The crude product was purified by silica gel chromatograph 330 g column eluting with 0-70% (EtOAc with 10% MeOH)/heptane. The desired peak was concentrated to constant mass to give 5.75 grams of crude product. The material was re-purified by silica gel chromatograph 330 g column eluting with 0-60% (EtOAc with 10% MeOH)/heptane to give 5.03 grams of crude product. The material was further purified by adding 1200 ml of ethyl acetate to dissolve and 200 ml of heptane, washed with 200 ml of 0.5 N HCl (5×), water, saturated sodium bicarbonate, water (3×), saturated salt solution, dried sodium sulfate, filtered and concentrated to constant mass to give 4.70 grams of desired product, yield used as is. (61% yield over two steps). LCMS (m/z): 805.4 (MH+), 0.99 min. 1H NMR (<cd3od>) d: 7.90 (s, 1H), 7.77-7.86 (m, 1H), 7.68-7.73 (m, 2H), 7.63 (dd, J=11.8, 1.2 Hz, 1H), 7.42-7.52 (m, 1H), 7.26 (d, J=9.5 Hz, 1H), 5.43 (t, J=5.7 Hz, 1H), 4.30-4.49 (m, 1H), 4.28 (t, J=6.3 Hz, 2H), 3.58-3.72 (m, 1H), 2.83 (t, J=11.6 Hz, 1H), 2.27 (dt, J=6.2, 3.1 Hz, 1H), 2.02-2.13 (m, 1H), 1.77-1.94 (m, 2H), 1.58-1.74 (m, 1H), 1.48-1.55 (m, 1H), 1.45 (d, J=5.8 Hz, 18H).
