(2S,4S)-Methyl 2-(2-fluorobenzyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate → 5-((2S,4S)-2-(2-fluorobenzyl)piperidin-4-yl)isoxazol-3(2H)-one

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Reaction Steps

(2S,4S)-Methyl 2-(2-fluorobenzyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (199 mg, 0.60 mmol) was stirred in hydrogen bromide (33% in AcOH) overnight (17 h). Evaporation of solvents and purification by preparative HPLC (Instrument: FractionLynx I, Mobilphase: gradient 5-95% MeCN in 0.2% NH3, pH 10, Column: Xbridge Prep C18 5 μm OBD 19*150 mm) yielded 5-((2S,4S)-2-(2-fluorobenzyl)piperidin-4-yl)isoxazol-3(2H)-one (115 mg, 70%). 1H NMR (600 MHz, DMSO) δ 1.47-1.56 (m, 1H), 1.67-1.81 (m, 3H), 2.57-2.64 (m, 1H), 2.72 (d, 2H), 2.81-2.87 (m, 1H), 2.87-2.95 (m, 1H), 3.12-3.18 (m, 1H), 5.70 (s, 1H), 7.09-7.18 (m, 2H), 7.22-7.33 (m, 2H). HRMS Calcd for [C15H17FN2O2+H]+: 277.1352. Found: 277.1352.

Provenance & Evidence