Hydrochloric Acid → 4H-1-Benzopyran-2-carboxylic acid, 6-hydroxy-4-oxo-, ethyl ester

HRID 1873554Notes

Reaction equation

HRID 1873554 reaction equation
[Na].[CH3:2][C:3]([C:5]1[CH:10]=[C:9]([OH:11])[CH:8]=[CH:7][C:6]=1[OH:12])=[O:4].[C:13](OCC)(=O)[C:14]([O:16][CH2:17][CH3:18])=[O:15].Cl>C(O)C>[OH:11][C:9]1[CH:10]=[C:5]2[C:6](=[CH:7][CH:8]=1)[O:12][C:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[CH:2][C:3]2=[O:4]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 7268Diethyl OxalateHCID 102792-AcetylhydroquinoneHCID 5360545Sodium

Product 1

HCID 6164644H-1-Benzopyran-2-carboxylic acid, 6-hydroxy-4-oxo-, ethyl ester

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

1.1 3.8 g of sodium are dissolved in portions in 300 ml of ethanol with stirring. A solution of 5.0 g of 2,5-dihydroxyacetophenone and 17.8 ml of diethyl oxalate in 25 ml of ethanol is subsequently added dropwise. The reaction mixture is then heated at 80° for 3 hours and cooled to room temperature, and 10 ml of 32% HCl are added dropwise. The mixture is heated at 90° for 30 minutes and cooled, and the solvent is removed. Conventional work-up gives 5.6 g of 6-hydroxy-2-ethoxycarbonylchromen-4-one (“AA”).

Workup

  1. temperatureThe reaction mixture is then heated at 80° for 3 hours
  2. temperatureThe mixture is heated at 90° for 30 minutes
  3. temperaturecooled
  4. customthe solvent is removed

Sources & evidence

ORD record
ord-f1cd8c1874fb4cafb78de0d1399a2ef6
Source dataset
uspto-grants-2012_11
Patent number
US08304416B2

Reaction notes

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