2,5-dimethyl-9-methoxy-2,3-dihydro-7H-furo[3,2-g][-1]benzopyran-7-one → 9-Methoxy-2,5-dimethyl-7h-furo[3,2-g]chromen-7-one

HRID 66078Notes

Reaction equation

HRID 66078 reaction equation
[CH3:1][CH:2]1[O:18][C:5]2=[C:6]([O:16][CH3:17])[C:7]3[O:12][C:11](=[O:13])[CH:10]=[C:9]([CH3:14])[C:8]=3[CH:15]=[C:4]2[CH2:3]1>C1(OC2C=CC=CC=2)C=CC=CC=1.[Pd]>[CH3:17][O:16][C:6]1[C:7]2[O:12][C:11](=[O:13])[CH:10]=[C:9]([CH3:14])[C:8]=2[CH:15]=[C:4]2[CH:3]=[C:2]([CH3:1])[O:18][C:5]=12

Participants

4

Reactant 1

HCID 203802242,5-dimethyl-9-methoxy-2,3-dihydro-7H-furo[3,2-g][-1]benzopyran-7-one

Product 1

HCID 1653059-Methoxy-2,5-dimethyl-7h-furo[3,2-g]chromen-7-one

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 7583Diphenyl EtherSolvent

Procedure

A solution of 10.36 g (0.0422 mol) of 2,5-dimethyl-9-methoxy -2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one in 150 ml of diphenyl ether was treated with 6.0 g of 10% palladium on charcoal. The mixture was heated under reflux for 5.0 hrs, cooled, and filtered over celite. The catalyst was further washed with methanol, and the filtrate was then concentrated to remove the methanol. The residue was diluted with 1.5 1. of pet. ether and stirred overnight. The product was filtered, washed with pet. ether, dried, and passed through a silica column, eluting with ethyl acetate/benzene, 1:4, to yield pure 9-methoxy -2,5-dimethyl-7H-furo[3,2-g][1]benzopyran-7-one, m.p. 154°-155° (ethanol).

Workup

  1. temperatureThe mixture was heated
  2. temperatureunder reflux for 5.0 hrs
  3. temperaturecooled
  4. filtrationfiltered over celite
  5. washThe catalyst was further washed with methanol
  6. concentrationthe filtrate was then concentrated
  7. customto remove the methanol
  8. additionThe residue was diluted with 1.5 1
  9. filtrationThe product was filtered
  10. washwashed with pet. ether
  11. customdried
  12. washeluting with ethyl acetate/benzene, 1:4

Sources & evidence

ORD record
ord-6bcfde82dd4c49a28b8073f4f0f1dae2
Source dataset
uspto-grants-1978_12
Patent number
US04130568

Reaction notes

Loading…