Hydrochloric Acid → 3-Amino-7-hydroxy-2H-1-benzopyran-2-one

HRID 2218537Notes

Reaction equation

HRID 2218537 reaction equation
[OH:1][C:2]1[CH:21]=[CH:20][C:5]2[CH:6]=[C:7]([NH:11]C(=O)C3C=CC=CC=3)[C:8](=[O:10])[O:9][C:4]=2[CH:3]=1.Cl.C(=O)([O-])O.[Na+]>C(O)CC>[NH2:11][C:7]1[C:8](=[O:10])[O:9][C:4]2[CH:3]=[C:2]([OH:1])[CH:21]=[CH:20][C:5]=2[CH:6]=1

Participants

5

Reactant 3

HCID 313Hydrochloric Acid2×HCID 516892Sodium BicarbonateHCID 5524061HCID 5524061, compound

Product 1

HCID 573458543-Amino-7-hydroxy-2H-1-benzopyran-2-oneYield 87.7%

Reagents, catalysts & solvents 1

HCID 10311-PropanolSolvent

Procedure

A mixture of N-(7-hydroxy-2-oxo-2H-1-benzopyran-3-yl)benzamide (230 mg, 0.82 mmol), 1-propanol (6 ml) and concentrated hydrochloric acid (2 ml) was refluxed for 3 hours. Then, hydrochloric acid (2 ml) was added and the mixture was refluxed for further 7 hours. After cooling, the reaction mixture was poured into saturated aqueous sodium hydrogen carbonate and extracted with ethyl acetate. The ethyl acetate layer was washed successively with water and saturated brine, and after the layer was dried over anhydrous sodium sulfate, the residue obtained by evaporation of the solvent under reduced pressure was purified by column chromatography on silica gel (eluent: dichloromethane/ethyl acetate=2/1) to give the title compound as a yellow solid (127 mg, 87.7%).

Workup

  1. temperaturewas refluxed for 3 hours
  2. temperaturethe mixture was refluxed for further 7 hours
  3. temperatureAfter cooling
  4. extractionextracted with ethyl acetate
  5. washThe ethyl acetate layer was washed successively with water and saturated brine
  6. dry with materialafter the layer was dried over anhydrous sodium sulfate
  7. customthe residue obtained by evaporation of the solvent under reduced pressure
  8. customwas purified by column chromatography on silica gel (eluent: dichloromethane/ethyl acetate=2/1)

Sources & evidence

ORD record
ord-b51569ba161244f1a28dabfb3140070f
Source dataset
uspto-grants-2008_08
Patent number
US07411076B2

Reaction notes

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