Hydrochloric Acid → (+/-)-tert-butyl 4-(3-amino-6-((1R,3R)-3-fluoro-4-oxocyclohexyl)pyrazin-2-yl)-2-fluorobenzoate

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Reaction Steps

To a solution of Imidodicarbonic acid, 4-(3-((tert-butoxycarbonyl)amino)-6-(3-fluoro-4-oxocyclohexyl)pyrazin-2-yl)-2-fluorobenzoate, 1,3-bis(1,1-dimethylethyl) ester (10.44 g, 17.29 mmol) in THF (57.6 mL) was added 4 M HCl in dioxane (130 mL, 519 mmol) at room temperature. The reaction mixture was stirred for 3-4 h, which was monitored by LCMS to prevent more of the t-butyl ester from hydrolyzing to carboxylic acid. The reaction was cooled in water bath, and neutralized with saturated sodium carbonate. The resulting mixture was extracted with EtOAc three times. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated. The residue was purified by flash chromatography eluting with 0-100% of EtOAc/heptane to provide (+/−)-tert-butyl 4-(3-amino-6-((1R,3R)-3-fluoro-4-oxocyclohexyl)pyrazin-2-yl)-2-fluorobenzoate (1.9 g, 4.71 mmol, 27.2%) and (+/−)-tert-butyl 4-(3-amino-6-((1S,3S)-3-fluoro-4-oxocyclohexyl)pyrazin-2-yl)-2-fluorobenzoate (926 mg, 2.295 mmol, 13.3%). LCMS (m/z): 404.3 (MH+), 0.84 min and 404.3 (MH+), 0.84 min respectively.

Provenance & Evidence