Hydroquinone → 7-((4-Methylene-5-oxo-2-phenyltetrahydro-2-furanyl)methoxy)-2H-chromen-2-one

HRID 263960Notes

Reaction equation

HRID 263960 reaction equation
[O:1]=[C:2]([C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)[CH2:3][O:4][C:5]1[CH:15]=[CH:14][C:8]2[CH:9]=[CH:10][C:11](=[O:13])[O:12][C:7]=2[CH:6]=1.C1(C=CC(O)=CC=1)O.Br[CH2:31][C:32](=[CH2:38])[C:33](OCC)=[O:34]>O1CCCC1.[Zn]>[CH2:31]=[C:32]1[C:33](=[O:34])[O:1][C:2]([CH2:3][O:4][C:5]2[CH:15]=[CH:14][C:8]3[CH:9]=[CH:10][C:11](=[O:13])[O:12][C:7]=3[CH:6]=2)([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)[CH2:38]1

Participants

6

Reactant 3

HCID 785HydroquinoneHCID 3106202-(Bromomethyl)acrylic acid ethyl esterHCID 8543337-(2-oxo-2-phenylethoxy)-2H-chromen-2-one

Product 1

HCID 3815097-((4-Methylene-5-oxo-2-phenyltetrahydro-2-furanyl)methoxy)-2H-chromen-2-oneYield 77.8%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 4a (0.84 g, 3 mmol) in dry tetrahydrofuran (60 ml) were added activated zinc powder (0.255 g, 3.9 mmol), hydroquinone (6 mg), and ethyl 2-(bromomethyl)acrylate (0.78 g, 4 mmol). The mixture was refluxed under nitrogen atmosphere for 18 h. (monitored by TLC). After cooling it was poured into an ice-cold 5% HCl solution (300 ml) and extracted with CH2Cl2 (75 ml×3). The dichloromethane extracts were combined and washed with saline, dried over Na2SO4, and then evaporated to give a residual solid which was crystallized from ethyl acetate to afford the title compound; Yield: 77.8%; mp: 105°-106° C.; IR(KBr) νmax : 1758, 1719, 1616; UV(CHCl3) λmax (log ε): 321 (4.22), 243 (3.62); 1H-NMR (CDCl3): δ3.24 (dt, 1H, 4'-H), 3.66(dt, 1H, 4'-H), 4.17, 4.24 (two d, 2H, OCH2), 5.71 (t, 1H, vinylic H), 6.24 (d, 1H, 3-H), 6.31 (t, 1H, vinylic H), 6.72 (d, 1H, 8-H), 6.78 (dd, 1H, 6-H), 7.35 (d, 1H, 5-H), 7.40-7.52 (m, 5H, aromatic H), 7.62 (d, 1H, 4-H). Anal Calcd for C21H16O5:C, 72.41; H, 4.63. Found: C, 72.30; H, 4.67.

Workup

  1. temperatureThe mixture was refluxed under nitrogen atmosphere for 18 h. (monitored by TLC)
  2. temperatureAfter cooling it
  3. extractionextracted with CH2Cl2 (75 ml×3)
  4. washwashed with saline
  5. dry with materialdried over Na2SO4
  6. customevaporated
  7. customto give a residual solid which
  8. customwas crystallized from ethyl acetate

Sources & evidence

ORD record
ord-bdcf8f31553e44408e7e78b35bf53909
Source dataset
uspto-grants-1997_07
Patent number
US05646164

Reaction notes

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