Hydrochloric Acid → Ethyl 7-hydroxy-4-oxo-8-propyl-4H-chromene-2-carboxylate

HRID 1414059Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1414059
[O-]CC.[Na+].[CH3:5][CH2:6][CH2:7][C:8]1[C:13]([OH:14])=[C:12]([C:15]([CH3:17])=[O:16])[CH:11]=[CH:10][C:9]=1[OH:18].[CH2:19]([O:21][C:22](=[O:28])[C:23](OCC)=O)[CH3:20].Cl>C(O)C.CCOCC>[OH:18][C:9]1[CH:10]=[CH:11][C:12]2[C:15](=[O:16])[CH:17]=[C:23]([C:22]([O:21][CH2:19][CH3:20])=[O:28])[O:14][C:13]=2[C:8]=1[CH2:7][CH2:6][CH3:5]

Komponenten

7

Edukt 4

HCID 313Hydrochloric AcidHCID 7268Diethyl OxalateHCID 2723922Sodium ethoxideHCID 27751982',4'-Dihydroxy-3'-propylacetophenone

Produkt 1

HCID 4196515Ethyl 7-hydroxy-4-oxo-8-propyl-4H-chromene-2-carboxylate

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 702EthanolLösungsmittelHCID 3283Diethyl EtherLösungsmittel

Versuchsvorschrift

To a solution of sodium ethoxide (from 19 gm. of sodium and 260 ml of absolute ethanol) under nitrogen atmosphere, add dropwise a solution of 40 gm of 2,4-dihydroxy-3-propylacetophenone and 68 gm of diethyloxalate in 55 ml of absolute ethanol and 55 ml of absolute ether. Heat under reflux for 3.5 hours. Cool to room temperature and pour the mixture into 500 ml of 5% aqueous hydrochloric acid. Extract the mixture twice with ether. Wash the combined organic fractions with water, dry over sodium sulfate and strip to a residue. Reflux the residue for 30 minutes in 150 ml absolute ethanol containing 2.5 ml of concentrated hydrochloric acid. Evaporate most of the ethanol and partition the residue between water and ethyl acetate. Wash the organic fraction with water, aqueous sodium bicarbonate solution and again with water. Dry over sodium sulfate and strip to a residue. Crystallize the residue from ethyl acetate-hexane to obtain a first crop (mp 155°-162° C.). Strip the mother liquors to dryness and chromatograph the residue over silica gel, eluting with a mixture of ethylacetate-hexane (1:1). Crystallize the resulting product from ethyl acetate to obtain a second crop. (mp 165°-167° C. lit. 166°-167° C.).

Aufarbeitung

  1. temperatureHeat
  2. temperatureunder reflux for 3.5 hours
  3. extractionExtract the mixture twice with ether
  4. washWash the combined organic fractions with water
  5. dry with materialdry over sodium sulfate and strip to a residue
  6. temperatureReflux the residue for 30 minutes in 150 ml absolute ethanol containing 2.5 ml of concentrated hydrochloric acid
  7. customEvaporate most of the ethanol
  8. custompartition the residue between water and ethyl acetate
  9. washWash the organic fraction with water, aqueous sodium bicarbonate solution
  10. dry with materialDry over sodium sulfate and strip to a residue
  11. customCrystallize the residue from ethyl acetate-hexane
  12. customto obtain a first crop (mp 155°-162° C.)
  13. washStrip the mother liquors to dryness and chromatograph the residue over silica gel, eluting with a mixture of ethylacetate-hexane (1:1)
  14. customCrystallize the resulting product from ethyl acetate
  15. customto obtain a second crop
  16. custom(mp 165°-167° C. lit. 166°-167° C.)

Quellen und Nachweise

ORD-Eintrag
ord-7610a2f6e34240b7b96fce16397d4a71
Quelldatensatz
uspto-grants-1981_02
Patentnummer
US04252818

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