Triethylamine → 1-Benzyl-3-acetyl-2,4-dioxopyrrolidine

HRID 977949Notes

Reaction equation

HRID 977949 reaction equation
Cl.CO[C:4](=[O:14])[CH2:5][NH:6][CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.C(N(CC)CC)C.[CH2:22]=[C:23]1[O:27][C:25](=[O:26])[CH2:24]1>C(O)C>[CH2:7]([N:6]1[CH2:5][C:4](=[O:14])[CH:24]([C:23](=[O:27])[CH3:22])[C:25]1=[O:26])[C:8]1[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 12661DiketeneHCID 24192994Methyl 2-(benzylamino)acetate hydrochloride

Product 1

HCID 136065761-Benzyl-3-acetyl-2,4-dioxopyrrolidineYield 87.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

N-Benzylglycine methyl ester hydrochloride (23.0 g) is dissolved in ethanol (180 ml) and thereto is added triethylamine (11.1 g) under ice-cooling and further added dropwise diketene (9.2 g). The mixture is stirred at room temperature for 1 hour and distilled to remove the solvent. The residue is dissolved in chloroform, washed with water, 10% hydrochloric acid, and water in this order, dried and then distilled to remove the solvent. The residue is dissolved in xylene (360 ml) and the solution is added dropwise to a solution of sodium methoxide [which is prepared from metal sodium (2.6 g) and methanol (180 ml)], and the mixture is stirred at 80° C. for 2.5 hours while distilling off methanol. After cooling, the reaction mixture is extracted with water. The extract is acidified with 10% hydrochloric acid and extracted with ethyl acetate. The ethyl acetate extract is washed with water, dried and distilled to remove the solvent. The residue is recrystallized from n-hexane-isopropyl ether-diethyl ether to give 1-benzyl-3-acetyl-2,4-dioxopyrrolidine (20.33 g, 87.7%). m.p. 74°-75° C.

Workup

  1. temperaturecooling
  2. distillationdistilled
  3. customto remove the solvent
  4. dissolutionThe residue is dissolved in chloroform
  5. washwashed with water, 10% hydrochloric acid, and water in this order
  6. customdried
  7. distillationdistilled
  8. customto remove the solvent
  9. dissolutionThe residue is dissolved in xylene (360 ml)
  10. additionthe solution is added dropwise to a solution of sodium methoxide [which is prepared from metal sodium (2.6 g) and methanol (180 ml)]
  11. stirringthe mixture is stirred at 80° C. for 2.5 hours
  12. distillationwhile distilling off methanol
  13. temperatureAfter cooling
  14. extractionthe reaction mixture is extracted with water
  15. extractionextracted with ethyl acetate
  16. extractionThe ethyl acetate extract
  17. washis washed with water
  18. customdried
  19. distillationdistilled
  20. customto remove the solvent
  21. customThe residue is recrystallized from n-hexane-isopropyl ether-diethyl ether

Sources & evidence

ORD record
ord-3e9c6af9ff80445a89c76fbb7c02f857
Source dataset
uspto-grants-1987_05
Patent number
US04663319

Reaction notes

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