Hydrochloric Acid → HCID 66732417, compound

Participants

Reaction Conditions

Reaction Steps

Methyl 4-(3-ethoxy-3-oxopropanoyl)-2-(3-fluoro-4-(trifluoromethyl)phenyl)piperidine-1-carboxylate (2.19 g, 5.22 mmol) was dissolved in MeOH (20 mL) and cooled to −40° C. under nitrogen. Sodium hydroxide (0.219 g, 5.48 mmol) dissolved in water (2.000 mL) was added and the mixture was stirred at −40° C. for 15 min. Hydroxylamine (50% by weight in water, 0.336 mL, 5.48 mmol) was added. The resulting solution was stirred at −40° C. for 1 h. The mixture was then transferred into a prewarmed (80° C.) solution of 6 M hydrogen chloride (27.0 mL, 161.89 mmol) and the mixture was stirred at 80° C. for 20 min. Water and DCM were added and the phases separated. The aqueous phase was extracted with DCM and the combined organic layers were filtered through a phase separator and evaporated. The compound was purified by preparative HPLC on a Kromasil C8 column (10 μm 250×50 ID mm) using a gradient of 15-55% Acetonitrile in H2O/MeCN/FA 95/5/0.2 buffer over 25 minutes with a flow of 100 mL/min. Methyl 2-(3-fluoro-4-(trifluoromethyl)phenyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)piperidine-1-carboxylate (0.670 g, 33.0%) was yielded as a colorless solid. 1H NMR (400 MHz, cdcl3) δ 1.82-1.93 (m, 1H), 2.12-2.44 (m, 3H), 3.04-3.16 (m, 1H), 3.35-3.46 (m, 1H), 3.69 (s, 3H), 4.11-4.21 (m, 1H), 5.09-5.18 (m, 1H), 5.56 (s, 1H), 6.97-7.09 (m, 2H), 7.52 (t, 1H). MS m/z 387 (M−H)−

Provenance & Evidence