Diethyl Ether → Benzyl 3-methyl-4-oxopiperidine-1-carboxylate

HRID 654129Notes

Reaction equation

HRID 654129 reaction equation
[CH2:1]([O:8][C:9](Cl)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(=O)(O)[O-].[Na+].CCOCC.Br.[CH3:23][CH:24]1[C:29](=[O:30])[CH2:28][CH2:27][NH:26][CH2:25]1>O>[CH2:1]([O:8][C:9]([N:26]1[CH2:27][CH2:28][C:29](=[O:30])[CH:24]([CH3:23])[CH2:25]1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 3283Diethyl EtherHCID 10387Benzyl chloroformateHCID 516892Sodium BicarbonateHCID 200945873-Methylpiperidin-4-one hydrobromide

Product 1

HCID 15233096Benzyl 3-methyl-4-oxopiperidine-1-carboxylate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a mechanically stirred mixture of benzylchloroformate (33.1 mL, 232 mmol, 105 mol %), sodium bicarbonate (37.2 g, 442 mmol, 200 mol %), ether (250 mL), and water (250 mL) is added 3-methyl-4-piperidone hydrobromide salt (42.9 g, 221 mmol) in portions over 10 min. The resultant mixture is stirred for 2 h and the organic phase separated. The aqueous phase is extracted with ether (2×150 mL) and the combined organics dried (MgSO4), filtered, and concentrated to an oily residue. This residue crystallized on standing at 23° C. and was recrystallized from hexanes/ethyl acetate to give N-benzyloxycarbonyl-3-methyl-4-piperidone as a solid: 51.2 g; 93%; mp 33°-35° C.

Workup

  1. customthe organic phase separated
  2. extractionThe aqueous phase is extracted with ether (2×150 mL)
  3. dry with materialthe combined organics dried (MgSO4)
  4. filtrationfiltered
  5. concentrationconcentrated to an oily residue
  6. customThis residue crystallized
  7. customon standing at 23° C.
  8. customwas recrystallized from hexanes/ethyl acetate

Sources & evidence

ORD record
ord-b217e9c4e5ec4ac482ce11b78b7296c4
Source dataset
uspto-grants-1992_07
Patent number
US05130321

Reaction notes

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