Tetrahydrofuran → 6-Methoxy-2H-1-benzopyran-3(4H)-one

HRID 364121Notes

Reaction equation

HRID 364121 reaction equation
[H-].[Na+].Br[C@H:4]1[C@H:9](O)[C:8]2[CH:11]=[C:12]([O:15][CH3:16])[CH:13]=[CH:14][C:7]=2[O:6][CH2:5]1.[O:17]1CCCC1>>[CH3:16][O:15][C:12]1[CH:13]=[CH:14][C:7]2[O:6][CH2:5][C:4](=[O:17])[CH2:9][C:8]=2[CH:11]=1

Participants

4

Reactant 3

HCID 8028Tetrahydrofuran2×HCID 24758Sodium hydrideHCID 12344687HCID 12344687, compound

Product 1

HCID 140069116-Methoxy-2H-1-benzopyran-3(4H)-one

Procedure

To a suspension of 2.0 g sodium hydride in 100 ml of dry tetrahydrofuran is added with stirring a solution of 20 g of trans-3-bromo-4-hydroxy-6-methoxy-3,4-dihydro-2H-[1]-benzopyran in 200 ml of dry tetrahydrofuran in a dropwise fashion. After 30 minutes stirring at room temperature, the reaction mixture is filtered through filter-cel and the solvent is removed in vacuo. The residue is dissolved in 100 ml of toluene, 1.0 g of anhydrous zinc iodide is added and the mixture is heated at 80° for 1 hour. The reaction mixture is filtered through 120 g of silica gel with methylene chloride as the eluent to afford a product which is recrystallized from ether to give 6-methoxy-2H-[1]-benzopyran-3-one, m.p. 67°-72°.

Workup

  1. additionis added
  2. filtrationthe reaction mixture is filtered
  3. filtrationthrough filter-cel
  4. customthe solvent is removed in vacuo
  5. dissolutionThe residue is dissolved in 100 ml of toluene
  6. addition1.0 g of anhydrous zinc iodide is added
  7. temperaturethe mixture is heated at 80° for 1 hour
  8. filtrationThe reaction mixture is filtered through 120 g of silica gel with methylene chloride as the eluent
  9. customto afford a product which
  10. customis recrystallized from ether

Sources & evidence

ORD record
ord-2029ab4ef4fa4a06b3bb10c6502e1eec
Source dataset
uspto-grants-1986_08
Patent number
US04604397

Reaction notes

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