Diketene → HCID 20204042, compound

HRID 977966Notes

Reaction equation

HRID 977966 reaction equation
C(OC(=O)[CH2:5][CH2:6][NH:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)C.[CH2:15]=[C:16]1[O:20][C:18](=[O:19])[CH2:17]1.[CH3:21][O-:22].[Na+]>C1C=CC=CC=1.CO>[C:8]1([N:7]2[CH2:6][CH2:5][C:21](=[O:22])[CH:17]([C:16](=[O:20])[CH3:15])[C:18]2=[O:19])[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1

Participants

6

Reactant 3

HCID 12661DiketeneHCID 10910393beta-Alanine, N-phenyl-, ethyl esterHCID 10942334Sodium Methoxide

Product 1

HCID 20204042HCID 20204042, compoundYield 81.6%

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 887MethanolSolvent2×

Conditions

Temperature
50 °C

Procedure

N-Phenyl-β-alanine ethyl ester (24,25 g) is dissolved in benzene (60 ml), and thereto is added dropwise diketene (12 ml) at 70° C. The mixture is refluxed overnight. The mixture is distilled to remove the solvent to give crude N-phenyl-N-methoxycarbonylmethylcarbonyl-β-alanine ethyl ester (37.23 g). Said crude compound is dissolved in methanol (70 ml), and the mixture is added dropwise to a solution of sodium methoxide (prepared from 3.90 g of sodium) in methanol (70 ml) at 50° C. The mixture is stirred at 50° C. for 2 hours, and distilled to remove the solvent. The residue is dissolved in water, and the aqueous solution is extracted with ethyl acetate. The aqueous layer is neutralized with 10% HCl, and extracted with ethyl acetate. The extract is washed with a saturated sodium chloride solution, dried and then distilled to remove the solvent. The residue is purified by silica gel column chromatography (solvent, ethyl acetate:n-hexane=1:2) to give 1-phenyl-3-acetyl-2,4-dioxopiperidine (23.87 g, 81.6%) as oil.

Workup

  1. temperatureThe mixture is refluxed overnight
  2. distillationThe mixture is distilled
  3. customto remove the solvent
  4. customto give crude N-phenyl-N-methoxycarbonylmethylcarbonyl-β-alanine ethyl ester (37.23 g)
  5. distillationdistilled
  6. customto remove the solvent
  7. dissolutionThe residue is dissolved in water
  8. extractionthe aqueous solution is extracted with ethyl acetate
  9. extractionextracted with ethyl acetate
  10. washThe extract is washed with a saturated sodium chloride solution
  11. customdried
  12. distillationdistilled
  13. customto remove the solvent
  14. customThe residue is purified by silica gel column chromatography (solvent, ethyl acetate:n-hexane=1:2)

Sources & evidence

ORD record
ord-67bb83cce6ff4e00bd13a49a19e38e63
Source dataset
uspto-grants-1987_05
Patent number
US04663319

Reaction notes

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