Hydrochloric Acid → 2,9-dimethoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one

HRID 66067Notes

Reaction equation

HRID 66067 reaction equation
Cl.[OH:2][CH:3]1[O:18][C:6]2=[C:7]([O:16][CH3:17])[C:8]3[O:13][C:12](=[O:14])[CH:11]=[CH:10][C:9]=3[CH:15]=[C:5]2[CH2:4]1.[CH3:19]O>>[CH3:19][O:2][CH:3]1[O:18][C:6]2=[C:7]([O:16][CH3:17])[C:8]3[O:13][C:12](=[O:14])[CH:11]=[CH:10][C:9]=3[CH:15]=[C:5]2[CH2:4]1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 887MethanolHCID 203802212-hydroxy-9-methoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one

Product 1

HCID 203802262,9-dimethoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one

Procedure

Dry methanol was saturated at 0° with gaseous hydrogen chloride. A sample of 0.576g. (2.46 mmoles) of 2-hydroxy-9-methoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one was dissolved in the resultant solution, and the dark reaction was allowed to proceed at room temperature for 1 hour. The solvent was evaporated and the residue was taken up in ethyl acetate/benzene, 1:4 and filtered through 50 g. silica, eluting with the same solvent system. Fractions containing the product, which is first eluted, were combined and evaporated to give pure 2,9-dimethoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one as a white solid. Recrystallization from methanol afforded an analytical sample of this product, mp 131-132°.

Workup

  1. customthe dark reaction
  2. customThe solvent was evaporated
  3. filtration1:4 and filtered through 50 g
  4. washsilica, eluting with the same solvent system
  5. additionFractions containing the product, which
  6. customevaporated

Sources & evidence

ORD record
ord-1e8989e6bfe44c98b8391fd2f5877959
Source dataset
uspto-grants-1978_12
Patent number
US04130568

Reaction notes

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