Ethylene Glycol → 1,4-Dioxa-7-azaspiro[4.5]decane

HRID 751658Notes

Reaction equation

HRID 751658 reaction equation
C([N:8]1[CH2:13][CH2:12][CH2:11][C:10](=[O:14])[CH2:9]1)(OC(C)(C)C)=O.[CH2:15](O)[CH2:16][OH:17].O.C1(C)C=CC(S(O)(=O)=O)=CC=1.C([O-])(O)=O.[Na+]>C1(C)C=CC=CC=1>[O:14]1[C:10]2([CH2:11][CH2:12][CH2:13][NH:8][CH2:9]2)[O:17][CH2:16][CH2:15]1

Participants

6

Reactant 4

HCID 174Ethylene GlycolHCID 516892Sodium BicarbonateHCID 521998p-Toluenesulfonic acid monohydrateHCID 2756825Tert-butyl 3-oxopiperidine-1-carboxylate

Product 1

HCID 123947731,4-Dioxa-7-azaspiro[4.5]decane

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 1-Boc-3-piperidone (700 mg, 3.51 mmol) in toluene (20 mL) was added ethylene glycol (588 μL, 10.54 mmol) followed by p-toluene sulfonic acid hydrate (1.0 g, 5.27 mmol) and the reaction heated to reflux using Dean-Stark apparatus for 7 h. To the mixture was added NaHCO3 solution, and the organic layer was removed. The aqueous phase was evaporated to dryness and the resulting residue dissolved in THF. Filtration through celite and removal of the solvent in vacuo gave the desired product as light brown oil. δH (CD3OD): 3.99 (2H, s), 3.73–3.57 (2H, m), 3.63 (4H, m), 2.77 (1H, m), 2.73 (1H, m), 1.76 (2H, m).

Workup

  1. temperaturethe reaction heated
  2. temperatureto reflux
  3. customfor 7 h
  4. customthe organic layer was removed
  5. customThe aqueous phase was evaporated to dryness
  6. dissolutionthe resulting residue dissolved in THF
  7. filtrationFiltration
  8. customthrough celite and removal of the solvent in vacuo

Sources & evidence

ORD record
ord-c2922f4255944063b6c592e9883625fc
Source dataset
uspto-grants-2008_07
Patent number
US07405210B2

Reaction notes

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