Sodium borohydride → tert-butyl 4-(3-amino-6-((1R,3R,4R)-3-fluoro-4-hydroxycyclohexyl)pyrazin-2-yl)-2-fluorobenzoate

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Reaction Steps

To a solution of (+/−)-tert-butyl 4-(3-amino-6-((1R,3R)-3-fluoro-4-oxocyclohexyl)pyrazin-2-yl)-2-fluorobenzoate (1.9 g, 4.71 mmol) in MeOH (47.1 mL) was added NaBH4 (0.267 g, 7.06 mmol) at 0° C. The reaction mixture was stirred for 2 h. After quenched with sat. NaHCO3 solution, the reaction mixture was extracted with EtOAc. The organic layer was washed with water and brine, dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by flash chromatography eluting with flat 35% of EtOAc in heptane to provide (+/−)-tert-butyl 4-(3-amino-6-((1S,3S,4S)-3-fluoro-4-hydroxycyclohexyl)pyrazin-2-yl)-2-fluorobenzoate (839 mg, 2.07 mmol, 43.9%) and (+/−)-tert-butyl 4-(3-amino-6-((1R,3R,4R)-3-fluoro-4-hydroxycyclohexyl)pyrazin-2-yl)-2-fluorobenzoate (900 mg, 2.22 mmol, 47%). LCMS (m/z): 406.3 (MH+), 0.85 min and 406.3 (MH+), 0.85 min respectively.

Provenance & Evidence