Dimethyl Sulfoxide → Benzopyran

HRID 1295884Notes

Reaction equation

HRID 1295884 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[CH:2]1.[CH3:10]S(C)=O.C1(=O)C=CC(=O)C=C1>C(Cl)Cl>[O:1]1[C:5]2[C:4](=[CH:9][CH:8]=[CH:7][CH:6]=2)[CH:3]=[CH:2][CH2:10]1

Participants

5

Reactant 3

HCID 679Dimethyl SulfoxideHCID 4650QuinoneHCID 9223Benzofuran

Product 1

HCID 9211BenzopyranYield 12%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

(±) 1,5-Dimethoxy-2′-isopropenyl dihydrofuroanoxanthone (107). DMSO (118 mL) was added to a mixture of (106) (1.21 g, 3.56 mmol), Pd[(CH3CN)4BF)2] (0.79 g, 1.78 mmol) and benzoquinone (recrystallized from EtOH, 3.84 g, 35.6 mmol). The solution was stirred 36 h, then poured into a separatory funnel containing CH2Cl2 (400 mL), and washed with H2O (2×300 mL). The layers were separated and the H2O layer was washed with CH2Cl2 (200 mL). The organic layers were combined and washed with sat. NaCl (200 mL), dried (Na2SO4) and concentrated under reduced pressure. The crude product was purified by column chromatography (50% EtOAc/hex), loading the product on the column in a minimum amount of CH2Cl2 to afford 0.15 g chromene (12%) and then 0.97 g (81%) of benzofuran (107) as a white solid. (LH-64-50).

Workup

  1. additionpoured into a separatory funnel
  2. washwashed with H2O (2×300 mL)
  3. customThe layers were separated
  4. washthe H2O layer was washed with CH2Cl2 (200 mL)
  5. washwashed with sat. NaCl (200 mL)
  6. dry with materialdried (Na2SO4)
  7. concentrationconcentrated under reduced pressure
  8. customThe crude product was purified by column chromatography (50% EtOAc/hex)

Sources & evidence

ORD record
ord-d381f53077814517bc4cf3950d3a973e
Source dataset
uspto-grants-2007_07
Patent number
US07244760B2

Reaction notes

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