Hydrogen Bromide → 5-((2R,4S)-2-(4-fluorobenzyl)piperidin-4-yl)isoxazol-3(2H)-one

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Reaction Steps

(2R,4S)-Methyl 2-(4-fluorobenzyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (647 mg, 1.94 mmol) was dissolved in hydrogen bromide (33% in acetic acid, 15 mL, 85.65 mmol) and the mixture stirred at room temperature overnight. The solvent was evaporated and the residue purified by preparative HPLC (Instrument: FractionLynx II, Mobilphase: gradient 5-95% MeCN in 0.2% NH3, pH 10, Column: Xbridge Prep C18 5 μm OBD 19*150 mm) to yield 5-((2R,4S)-2-(4-fluorobenzyl)piperidin-4-yl)isoxazol-3(2H)-one (360 mg, 67%). 1H NMR (600 MHz, DMSO) δ 1.08 (q, 1H), 1.37 (dq, 1H), 1.73-1.81 (m, 2H), 2.44-2.73 (m, 5H), 2.96-3.03 (m, 1H), 5.70 (s, 1H), 7.07-7.14 (m, 2H), 7.21-7.27 (m, 2H). HRMS Calculated for [C15H17FN2O2+H]+: 277.1352. Found: 277.1333

Provenance & Evidence