Pyridine → 2H-1-Benzopyran, 3-acetyl-7-methoxy-

HRID 1110419Notes

Reaction equation

HRID 1110419 reaction equation
[OH:1][C:2]1[CH:9]=[C:8]([O:10][CH3:11])[CH:7]=[CH:6][C:3]=1[CH:4]=O.[O:12]=[C:13]([CH3:16])[CH:14]=[CH2:15].N1C=CC=CC=1.C(=O)([O-])[O-].[K+].[K+].[OH-].[Na+]>CN(C)C=O>[CH3:11][O:10][C:8]1[CH:9]=[C:2]2[C:3]([CH:4]=[C:14]([C:13](=[O:12])[CH3:16])[CH2:15][O:1]2)=[CH:6][CH:7]=1

Participants

7

Reactant 5

HCID 1049PyridineHCID 6570Methyl vinyl ketoneHCID 11430Potassium CarbonateHCID 14798Sodium HydroxideHCID 696002-Hydroxy-4-Methoxybenzaldehyde

Product 1

HCID 424342H-1-Benzopyran, 3-acetyl-7-methoxy-

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

1.52 g (10 mmol) of 2-hydroxy-4-methoxybenzaldehyde, 0.66 g (10 mmol) of 3-oxo-1-butene and 0.79 g (10 mmol) of pyridine are added at room temperature and with mechanical stirring to a suspension of 0.14 g (1 mmol) of potassium carbonate in 100 ml of dimethylformamide. The mixture is brought to reflux while magnetic stirring is maintained for 6 hours. The reaction medium is then poured into 200 ml of 0.5 N aqueous sodium hydroxide solution and thereafter extracted three times with 100 ml of diethyl ether. The organic phases are combined, washed twice with 100 ml of saturated aqueous sodium chloride solution and dried. The solvents are evaporated off and the product is purified by chromatography (see Table Al)

Workup

  1. temperatureto reflux
  2. temperatureis maintained for 6 hours
  3. extractionextracted three times with 100 ml of diethyl ether
  4. washwashed twice with 100 ml of saturated aqueous sodium chloride solution
  5. customdried
  6. customThe solvents are evaporated off
  7. customthe product is purified by chromatography (see Table Al)

Sources & evidence

ORD record
ord-04ca51698f40456da4abd3d12c7d6e49
Source dataset
uspto-grants-1990_12
Patent number
US04975455

Reaction notes

Loading…