Ethyl benzoylacetate → HCID 20262554, compound

HRID 464765Notes

Reaction equation

HRID 464765 reaction equation
[C:1]([CH2:9][C:10]([O:12]CC)=[O:11])(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:15](=[O:18])(O)[O-].[Na+]>C(O)C>[C:2]1([C:1]2[O:8][C:1]([C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=3)=[CH:9][C:15](=[O:18])[C:9]=2[C:10]([OH:12])=[O:11])[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Procedure

A 250 ml round-bottom flask is equipped with a mechanical stirrer, thermometer, and a distillation head and condenser set up to remove distillate. The flask is charged with 100 g (0.52 moles) ethyl benzoylacetate and 0.075 g sodium bicarbonate. The flask and its contents are heated by means of an oil bath over a period of about 5 hours at temperature from ambient to a maximum of 200° C. while the ethanol formed is continuously removed. Unreacted ethyl benzoylacetate is removed by vaccum distillation. The residue consisting of crude 3-benzoyl-6-phenyl-2H-pyran-2,4-(3H)-dione is then heated at 80°-85° C. with 500 g of 85% sulfuric acid for 4 hours. This mixture is poured into 1 liter of ice-water and the water extracted three times with 150 ml portions of chloroform. The combined chloroform extracts are stripped of volatiles on a rotary evaporator and the residue of 2,6-diphenyl-4-oxopyran-3-carboxylic acid isolated by fractional crystallization. A toluene solution of this pyrone is then treated with an equal molar quantity of 4-amino-2,2,6,6-tetramethylpiperidine and refluxed with removal of water by means of a Dean-Stark trap. When water has ceased to separate, the toluene is removed on a rotary evaporator and the residue cooled and treated with hexane to promote crystallization of the crude product. The product is further purified by fractional crystallization.

Workup

  1. customA 250 ml round-bottom flask is equipped with a mechanical stirrer
  2. customto remove distillate
  3. customformed
  4. customis continuously removed
  5. customUnreacted ethyl benzoylacetate is removed by vaccum distillation
  6. temperatureis then heated at 80°-85° C. with 500 g of 85% sulfuric acid for 4 hours
  7. additionThis mixture is poured into 1 liter of ice-water
  8. extractionthe water extracted three times with 150 ml portions of chloroform
  9. customThe combined chloroform extracts are stripped of volatiles on a rotary evaporator

Sources & evidence

ORD record
ord-e67a7a81d14b48eebbeecc376de43217
Source dataset
uspto-grants-1985_10
Patent number
US04548973

Reaction notes

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