Hydrochloric Acid → Tert-butyl 4-(2,4-difluorobenzyl)-4-hydroxypiperidine-1-carboxylate

HRID 60606Notes

Reaction equation

HRID 60606 reaction equation
[Mg].BrCCBr.[F:6][C:7]1[CH:14]=[C:13]([F:15])[CH:12]=[CH:11][C:8]=1[CH2:9]Br.[O:16]=[C:17]1[CH2:22][CH2:21][N:20]([C:23]([O:25][C:26]([CH3:29])([CH3:28])[CH3:27])=[O:24])[CH2:19][CH2:18]1.Cl.C(C(C(C([O-])=O)O)O)([O-])=O.[Na+].[K+]>C(OCC)C.C1COCC1>[F:6][C:7]1[CH:14]=[C:13]([F:15])[CH:12]=[CH:11][C:8]=1[CH2:9][C:17]1([OH:16])[CH2:18][CH2:19][N:20]([C:23]([O:25][C:26]([CH3:28])([CH3:27])[CH3:29])=[O:24])[CH2:21][CH2:22]1

Participants

9

Conditions

Temperature
-78 °C

Procedure

To a suspension of magnesium (1.2 g) and 1,2-dibromoethane (0.11 mL) in diethyl ether (30 mL) was added a solution of 2,4-difluorobenzyl bromide (10 g) in diethyl ether (10 mL) at room temperature under a nitrogen atmosphere, and the mixture was stirred at the same temperature for 1 hr. The reaction mixture was diluted with THF (30 mL), and cooled to −78° C., and a solution of tert-butyl 4-oxopiperidine-1-carboxylate (5.0 g) in THF (10 mL) was added thereto. The mixture was allowed to warm to room temperature, and stirred overnight. To the reaction mixture was added a small amount of 1N hydrochloric acid at 0° C. to quench the reaction. Saturated aqueous potassium sodium tartrate solution was added thereto, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (NH, ethyl acetate/hexane), and recrystallized from ethyl acetate/hexane to give the title compound (3.9 g).

Workup

  1. temperatureto warm to room temperature
  2. stirringstirred overnight
  3. customto quench
  4. customthe reaction
  5. extractionthe mixture was extracted with ethyl acetate
  6. washThe extract was washed with saturated brine
  7. dry with materialdried over anhydrous sodium sulfate
  8. customThe solvent was evaporated under reduced pressure
  9. customThe residue was purified by silica gel column chromatography (NH, ethyl acetate/hexane)
  10. customrecrystallized from ethyl acetate/hexane

Sources & evidence

ORD record
ord-2748c4a3e7c748fc830bc2f638d8cc06
Source dataset
uspto-grants-2016_09
Patent number
US09440990B2

Reaction notes

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