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

Participants

Reaction Steps

(2S,4R)-Methyl 4-(3-oxo-2,3-dihydroisoxazol-5-yl)-2-(4-(trifluoromethyl)phenyl)piperidine-1-carboxylate (591 mg, 1.60 mmol) (from example 33, step 3) was dissolved in hydrogen bromide (33% in acetic acid, 12 mL, 68.52 mmol) and the mixture stirred at room temperature. After 24 h more hydrogen bromide (33% in acetic acid, 5 mL, 28.55 mmol) was added and the reaction continued at room temperature for a total of 1.5 days. The solvent was evaporated and the residue purified by preparative HPLC (Instrument: FractionLynx III, Mobilphase: gradient 5-95% MeCN in 0.2% NH3, pH10, Column: Xbridge Prep C18 5 μm OBD 19*150 mm) to yield 5-((2S,4R)-2-(4-(trifluoromethyl)phenyl)piperidin-4-yl)isoxazol-3(2H)-one (337 mg, 67%). 1H NMR (600 MHz, cd3od) δ 1.69-1.78 (m, 2H), 2.09 (d, 1H), 2.21 (d, 1H), 2.99-3.09 (m, 2H), 3.32-3.38 (m, 1H), 4.01-4.04 (m, 1H), 5.63 (s, 1H), 7.59 (d, 2H), 7.66 (d, 2H). HRMS Calculated for [C15H15F3N2O2+H]+: 313.1164. Found: 313.1156

Provenance & Evidence