反应详情

温度

-40 °C

Cis-methyl 4-(3-ethoxy-3-oxopropanoyl)-2-(3,4,5-trifluorophenyl)piperidine-1-carboxylate (810 mg, 2.09 mmol) was dissolved in MeOH (8 mL) and cooled to −40° C. under nitrogen. Sodium hydroxide (0.615 mL, 2.09 mmol) was added during 10 min and the yellow solution continued to stir at −40° C. for 20 min. Hydroxylamine (50% by weight in water, 0.128 mL, 2.09 mmol) was added during 8 min. The resulting solution was stirred at −40° C. for 3 h. The mixture was then rapidly poured into a prewarmed (80° C.) solution of 6 M hydrogen chloride (10.77 mL, 64.62 mmol) and the mixture continued to stir at 80° C. for 20 min. The solvent was evaporated and DCM/water added. The phases were separated and the organic phase passed through a phase separator and evaporated to yield a white solid. 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 4-(3-oxo-2,3-dihydroisoxazol-5-yl)-2-(3,4,5-trifluoro-phenyl)piperidine-1-carboxylate (355 mg, 48%) was isolated. MS m/z 357 (M+H)+

1. stirringThe resulting solution was stirred at −40° C. for 3 h
2. stirringto stir at 80° C. for 20 min
3. customThe solvent was evaporated
4. additionDCM/water added
5. customThe phases were separated
6. customevaporated
7. customto yield a white solid
8. customThe compound was purified by preparative HPLC on a Kromasil C8 column (10 μm 250×50 ID mm)
9. custombuffer over 30 minutes