Hydrochloric Acid → Ethyl 7-amino-4-oxo-4H-chromene-2-carboxylate

HRID 904685Notes

Reaction equation

HRID 904685 reaction equation
[Na].[C:2]([C:5]1[CH:10]=[CH:9][C:8]([NH:11]C(=O)C)=[CH:7][C:6]=1[OH:15])(=[O:4])[CH3:3].[C:16](OCC)(=O)[C:17]([O:19][CH2:20][CH3:21])=[O:18].Cl>C(O)C.C(Cl)(Cl)Cl.O>[NH2:11][C:8]1[CH:9]=[CH:10][C:5]2[C:2](=[O:4])[CH:3]=[C:16]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[O:15][C:6]=2[CH:7]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 7268Diethyl OxalateHCID 2775185N-(4-acetyl-3-hydroxyphenyl)acetamideHCID 5360545Sodium

Product 1

HCID 10728325Ethyl 7-amino-4-oxo-4H-chromene-2-carboxylate

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolventHCID 6212ChloroformSolvent2×

Procedure

A solution of sodium metal, (18.4 g, 0.8 gatom), in dry ethanol (1200 ml), was treated with N-(4-acetyl-3-hydroxyphenyl)acetamide (30.88 g, 0.16 mole). This mixture was stirred for 15 mins then diethyl oxalate (58.4 g, 54.3 ml, 0.4 mole), was added dropwise over 30 mins. The resulting mixture was heated and stirred at 60° C. for 2 hrs, allowed to cool and poured into a mixture of chloroform (600 ml), conc HCl (85 ml), and water (2000 ml). The organic layer was isolated and combined with a chloroform wash of the aqueous layer. The combined chloroform extracts were washed well with water then evaporated to dryness. The residue was taken into ethanol (400 ml), and conc.HCl (10 ml), was also added. The solution was heated at reflux for 30 minutes then evaporated to dryness. The residue was treated with ether and ethanol was added dropwise until the residue began to solidify. Insoluble material was filtered off, washed again with ether and the required sub-title product was recovered as a brown solid (20.5 g), (55%), mp 192°-194°. NMR and mass spectra confirmed the structure.

Workup

  1. temperatureThe resulting mixture was heated
  2. stirringstirred at 60° C. for 2 hrs
  3. temperatureto cool
  4. customThe organic layer was isolated
  5. washwash of the aqueous layer
  6. washThe combined chloroform extracts were washed well with water
  7. customthen evaporated to dryness
  8. additionHCl (10 ml), was also added
  9. temperatureThe solution was heated
  10. temperatureat reflux for 30 minutes
  11. customthen evaporated to dryness
  12. additionThe residue was treated with ether and ethanol
  13. additionwas added dropwise until the residue
  14. filtrationInsoluble material was filtered off
  15. washwashed again with ether
  16. customthe required sub-title product was recovered as a brown solid (20.5 g), (55%), mp 192°-194°

Sources & evidence

ORD record
ord-691816971fca4d65a7f002ee539aa85a
Source dataset
uspto-grants-1983_12
Patent number
US04419352

Reaction notes

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