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

HRID 1448510Notes

Reaction equation

HRID 1448510 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.[CH2:19](O)[CH3:20]>>[CH2:19]([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)[CH3:20]

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 702EthanolHCID 203802212-hydroxy-9-methoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one

Product 1

HCID 203802252-ethoxy-9-methoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one

Procedure

Absolute ethanol was saturated with gaseous hydrogen chloride at 0°. To this solution, 5.0 g. (0.214 mole) of 2-hydroxy-9-methoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one was added, and the reaction was allowed to proceed at 25° for 2.0 hours. The solvent was evaporated, and the residue was passed through a column consisting of 150 g. silica (upper layer) and 50 g. of neutral alumina (lower layer) using benzene/ethyl acetate, 4:1. Fractions containing the product were combined and evaporated to afford pure 2-ethoxy-9-methoxy-2,3-dihydro-7H-furo[3,2-g][1]benzopyran-7-one as a white solid. Recrystallization from ethanol yielded an analytical sample, mp 119°-120°.

Workup

  1. customThe solvent was evaporated
  2. additionFractions containing the product
  3. customevaporated

Sources & evidence

ORD record
ord-eb9b764c21a147e28230169fd05983be
Source dataset
uspto-grants-1979_12
Patent number
US04180659

Reaction notes

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