Hydrochloric Acid → (2R,4S)-Methyl 4-(3-oxo-2,3-dihydroisoxazol-5-yl)-2-(4-(trifluoromethyl)phenyl)piperidine-1-carboxylate

HRID 1963382Notes

Reaction equation

HRID 1963382 reaction equation
C([O:3][C:4](=O)[CH2:5][C:6]([C@H:8]1[CH2:13][CH2:12][N:11]([C:14]([O:16][CH3:17])=[O:15])[C@@H:10]([C:18]2[CH:23]=[CH:22][C:21]([C:24]([F:27])([F:26])[F:25])=[CH:20][CH:19]=2)[CH2:9]1)=[O:7])C.[OH-].[Na+].[NH2:31]O.Cl>CO.O>[O:3]=[C:4]1[CH:5]=[C:6]([C@H:8]2[CH2:13][CH2:12][N:11]([C:14]([O:16][CH3:17])=[O:15])[C@@H:10]([C:18]3[CH:23]=[CH:22][C:21]([C:24]([F:27])([F:26])[F:25])=[CH:20][CH:19]=3)[CH2:9]2)[O:7][NH:31]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 787HydroxylamineHCID 14798Sodium HydroxideHCID 131730391cis-Methyl 4-(3-ethoxy-3-oxopropanoyl)-2-(4-(trifluoromethyl)phenyl)-piperidine-1-carboxylate

Product 1

HCID 66739070(2R,4S)-Methyl 4-(3-oxo-2,3-dihydroisoxazol-5-yl)-2-(4-(trifluoromethyl)phenyl)piperidine-1-carboxylateYield 79%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Conditions

Temperature
-40 °C

Procedure

Cis-methyl 4-(3-ethoxy-3-oxopropanoyl)-2-(4-(trifluoromethyl)phenyl)piperidine-1-carboxylate (2.307 g, 5.75 mmol) was dissolved in MeOH (20 mL) and cooled to −40° C. under nitrogen. Sodium hydroxide (0.230 g, 5.75 mmol) dissolved in water (2 mL) was added during 10 min and the colourless solution continued to stir at −40° C. for 20 min. Hydroxylamine (50% by weight in water, 0.352 mL, 5.75 mmol) was added during 8 min. The resulting solution was stirred at −40° C. for 3 h 20 min. The mixture was then transferred into a prewarmed (80° C.) solution of 6 M hydrogen chloride (30 mL, 180.00 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 yellow solid. The compound was purified by preparative HPLC in 3 injections on a XBridge C18 column (10 μm 250×50 ID mm) using a gradient of 0-25% Acetonitrile in H2O/MeCN/NH3 95/5/0.2 buffer over 20 minutes with a flow of 100 mL/min. Cis-methyl 4-(3-oxo-2,3-dihydroisoxazol-5-yl)-2-(4-(trifluoromethyl)phenyl)piperidine-1-carboxylate (1.682 g, 79%) was isolated as a white solid. 1H NMR (400 MHz, cd3od) δ 1.83-1.94 (m, 1H), 2.16-2.29 (m, 2H), 2.34-2.43 (m, 1H), 3.06-3.18 (m, 1H), 3.51 (ddd, 1H), 3.64 (s, 3H), 4.12 (ddd, 1H), 5.10-5.22 (m, 1H), 5.57 (s, 1H), 7.40 (d, 2H), 7.58 (d, 2H). MS m/z 371 (M+H)+

Workup

  1. additionwas added during 10 min
  2. stirringThe resulting solution was stirred at −40° C. for 3 h 20 min
  3. stirringto stir at 80° C. for 20 min
  4. customThe solvent was evaporated
  5. additionDCM/water added
  6. customThe phases were separated
  7. customevaporated
  8. customto yield a yellow solid
  9. customThe compound was purified by preparative HPLC in 3 injections on a XBridge C18 column (10 μm 250×50 ID mm)
  10. custombuffer over 20 minutes

Sources & evidence

ORD record
ord-5432386becb64940ba3cba67f9ddae50
Source dataset
uspto-grants-2013_04
Patent number
US08415378B2

Reaction notes

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