7-Hydroxy-8-methoxy-4-methyl-6-(prop-2-en-1-yl)-2H-1-benzopyran-2-one → 2,5-dimethyl-9-methoxy-2,3-dihydro-7H-furo[3,2-g][-1]benzopyran-7-one

HRID 1448520Notes

Reaction equation

HRID 1448520 reaction equation
[CH2:1]([C:4]1[CH:5]=[C:6]2[C:11](=[C:12]([O:15][CH3:16])[C:13]=1[OH:14])[O:10][C:9](=[O:17])[CH:8]=[C:7]2[CH3:18])[CH:2]=[CH2:3]>S(=O)(=O)(O)O>[CH3:3][CH:2]1[O:14][C:13]2=[C:12]([O:15][CH3:16])[C:11]3[O:10][C:9](=[O:17])[CH:8]=[C:7]([CH3:18])[C:6]=3[CH:5]=[C:4]2[CH2:1]1

Participants

3

Reactant 1

HCID 218145027-Hydroxy-8-methoxy-4-methyl-6-(prop-2-en-1-yl)-2H-1-benzopyran-2-one

Product 1

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

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

A sample of 15.0 g (0.0612 mol) of 6-allyl-7-hydroxy-8-methoxy-4-methylcoumarin was treated with 30 ml of conc. sulfuric acid at 25°. After 10 min, the dark mixture was diluted with 400 ml of ice water and extracted three times with methylene chloride/methanol, 4:1. The organic phases were dried and evaporated; the residue was filtered through 250 g silica, diluting with ethyl acetate/benzene, 1:4 to afford pure 2,5-dimethyl-9-methoxy-2,3-dihydro-7H-furo[3,2-g][1]-benzopyran-7-one, m.p. 113°-115°, as a white crystalline solid. Recrystallization from ethanol gave an analytical sample, m.p. 114°-115°.

Workup

  1. extractionextracted three times with methylene chloride/methanol, 4:1
  2. customThe organic phases were dried
  3. customevaporated
  4. filtrationthe residue was filtered through 250 g silica
  5. additiondiluting with ethyl acetate/benzene, 1:4

Sources & evidence

ORD record
ord-4c270356ff884d0d81bed726166c8d08
Source dataset
uspto-grants-1979_12
Patent number
US04180659

Reaction notes

Loading…