p-Toluenesulfonic acid → tert-Butyl 3-hydroxy-4-oxopiperidine-1-carboxylate

HRID 38537Notes

Reaction equation

HRID 38537 reaction equation
[OH:1][CH:2]1[C:7](OC)([O:8]C)[CH2:6][CH2:5][N:4]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:3]1.C1(C)C=CC(S(O)(=O)=O)=CC=1>CC(C)=O>[OH:1][CH:2]1[C:7](=[O:8])[CH2:6][CH2:5][N:4]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:3]1

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 11425480Tert-butyl 3-hydroxy-4,4-dimethoxypiperidine-1-carboxylate

Product 1

HCID 58116959tert-Butyl 3-hydroxy-4-oxopiperidine-1-carboxylateYield 107.9%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

tert-Butyl 3-hydroxy-4,4-dimethoxypiperidine-1-carboxylate from Example 44A (5.24 g, 20.1 mmol) was dissolved in acetone (100 mL), and p-toluene sulfonic acid (173 mg, 1.00 mmol) was added. The mixture was stirred at rt for 3 days, then filtered, and the filtrate was concentrated. The residue was dissolved in tert-butyl methyl ether and extracted with satd. aqueous sodium bicarbonate solution. The organic layer was dried over sodium sulfate, and the solvent was removed in vacuo to yield 4.67 g of an oil (64% purity, 69% yield), which was used in the next step without further purification.

Workup

  1. filtrationfiltered
  2. concentrationthe filtrate was concentrated
  3. dissolutionThe residue was dissolved in tert-butyl methyl ether
  4. extractionextracted with satd
  5. dry with materialThe organic layer was dried over sodium sulfate
  6. customthe solvent was removed in vacuo

Sources & evidence

ORD record
ord-eac4fd5a6aa345cfacabdc5e818a329f
Source dataset
uspto-grants-2013_09
Patent number
US08524722B2

Reaction notes

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