Sulfuric Acid → Ethyl 3-(benzyloxy)-4-oxopiperidine-1-carboxylate

HRID 846745Notes

Reaction equation

HRID 846745 reaction equation
C[O:2][C:3]1(OC)[CH2:8][CH2:7][N:6]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:5][CH:4]1[O:14][CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.S(=O)(=O)(O)O>O>[O:2]=[C:3]1[CH2:8][CH2:7][N:6]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:5][CH:4]1[O:14][CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 3019743Ethyl 3-(benzyloxy)-4,4-dimethoxypiperidine-1-carboxylate

Product 1

HCID 3019711Ethyl 3-(benzyloxy)-4-oxopiperidine-1-carboxylate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 94 parts of ethyl 4,4-dimethoxy-3-(phenylmethoxy)-1-piperidinecarboxylate and 2300 parts of a sulfuric acid solution 1% in water was stirred and refluxed for 2.50 hours. The reaction mixture was cooled and the product was extracted three times with dichloromethane. The combined extracts were washed with a small amount of water, dried, filtered and evaporated. The residue was taken up in methylbenzene and the latter was evaporated again. The residue was stirred in petroleumether. The latter was separated and the solvent was evaporated, yielding 64.9 parts of ethyl 4-oxo-3-(phenylmethoxy)-1-piperidinecarboxylate as a residue (intermediate 50).

Workup

  1. temperaturerefluxed for 2.50 hours
  2. temperatureThe reaction mixture was cooled
  3. extractionthe product was extracted three times with dichloromethane
  4. washThe combined extracts were washed with a small amount of water
  5. customdried
  6. filtrationfiltered
  7. customevaporated
  8. customthe latter was evaporated again
  9. stirringThe residue was stirred in petroleumether
  10. customThe latter was separated
  11. customthe solvent was evaporated

Sources & evidence

ORD record
ord-67b7f05b843a4f73bfb1f109cce23913
Source dataset
uspto-grants-1992_08
Patent number
US05137896

Reaction notes

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