Water → 7-Ethoxy-6-hydroxy-2H-1-benzopyran-2-one

HRID 22360

Reaction equation

HRID 22360 reaction equation
[CH:1]1[C:11]2[C:6](=[CH:7][C:8]([OH:24])=[C:9]([O:12][C@@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@H]3O)[CH:10]=2)[O:5][C:3](=[O:4])[CH:2]=1.O.[CH2:26](I)[CH3:27].C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C>[CH2:26]([O:24][C:8]1[C:9]([OH:12])=[CH:10][C:11]2[CH:1]=[CH:2][C:3](=[O:4])[O:5][C:6]=2[CH:7]=1)[CH3:27]

Participants

6

Reactant 4

HCID 962WaterHCID 6340IodoethaneHCID 11430Potassium CarbonateHCID 5281417Esculin

Product 1

HCID 130316867-Ethoxy-6-hydroxy-2H-1-benzopyran-2-one

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

110 g (300 mmol) esculine×1.5 H2O, 70 g (450 mmol) ethyl iodide and 82.8 g (600 mmol) of potassium carbonate are agitated in 400 ml DMF for 30 h at 85° C. This was followed by filtration, reduction of the filtrate to approximately 250 ml, the addition of approximately 200 ml ethanol and crystallization at 0° C. The crystals were boiled in 800 ml of 2N sulfuric acid for 5 h under reflux. The product was vacuum filtered, washed with water and recrystallized from water and ethanol: yield 43.2 g (70%), fusion point 145° to 146° C.

Workup

  1. filtrationThis was followed by filtration, reduction of the filtrate to approximately 250 ml
  2. additionthe addition of approximately 200 ml ethanol and crystallization at 0° C
  3. temperatureunder reflux
  4. filtrationfiltered
  5. washwashed with water
  6. customrecrystallized from water and ethanol
  7. customyield 43.2 g (70%), fusion point 145° to 146° C.

Sources & evidence

ORD record
ord-fca3f46a3ae048f68d56fb69c68edcef
Source dataset
uspto-grants-1995_06
Patent number
US05428038

Linked notes

Loading…