Hydrochloric Acid → HCID 68502958, compound

Participants

Reaction Conditions

Reaction Steps

Cis-methyl 2-(4-chloro-3-fluorophenyl)-4-(3-ethoxy-3-oxopropanoyl)piperidine-1-carboxylate (1.731 g, 4.49 mmol) was dissolved in MeOH (20 mL) and cooled to −40° C. under nitrogen. Sodium hydroxide (1.181 mL, 4.49 mmol) dissolved in water (2 mL) was added and the reaction stirred at −40° C. for 20 min. Hydroxylamine (50% by weight in water, 0.247 mL, 4.49 mmol) was added dropwise and stirring continued for 3 h. The mixture was then transferred to a prewarmed 80° C. solution of 6 M hydrogen chloride (23.18 mL, 139.09 mmol) and stirring was continued at 80° C. for 20 min. The solvent was evaporated and DCM (200 mL) and water (200 mL) were added. The phases were shaken, separated and the organic phase dried with a phase separator and evaporated in vacuo. The compound was purified by preparative HPLC on a Kromasil C8 column (10 μm 250×50 ID mm) using a gradient of 10-60% Acetonitrile in H2O/MeCN/AcOH 95/5/0.2 buffer over 30 minutes with a flow of 100 mL/min. Cis-methyl 2-(4-chloro-3-fluorophenyl)-4-(3-oxo-2,3-dihydroisoxazol-5-yl)-piperidine-1-carboxylate (0.921 g, 57.9%) was isolated as a white solid. 1H NMR (600 MHz, cdcl3) δ 1.79-1.87 (m, 1H), 2.06-2.15 (m, 1H), 2.19-2.28 (m, 1H), 2.30-2.37 (m, 1H), 3.00-3.09 (m, 1H), 3.31-3.40 (m, 1H), 3.66 (s, 3H), 4.07-4.16 (m, 1H), 5.00-5.07 (m, 1H), 5.56 (s, 1H), 6.87-6.91 (m, 1H), 6.95 (dd, 1H), 7.29 (t, 1H). MS m/z 355 (M+H)+

Provenance & Evidence