2-(Bromomethyl)acrylic acid ethyl ester → 4-((2-Methyl-4-methylene-5-oxotetrahydro-2-furanyl)methoxy)-2H-chromen-2-one

HRID 263954Notes

Reaction equation

HRID 263954 reaction equation
[O:1]=[C:2]([CH3:16])[CH2:3][O:4][C:5]1[C:10]2[CH:11]=[CH:12][CH:13]=[CH:14][C:9]=2[O:8][C:7](=[O:15])[CH:6]=1.Br[CH2:18][C:19](=[CH2:25])[C:20](OCC)=[O:21]>O1CCCC1.[Zn].C1(C=CC(O)=CC=1)O>[CH3:16][C:2]1([CH2:3][O:4][C:5]2[C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][C:9]=3[O:8][C:7](=[O:15])[CH:6]=2)[CH2:25][C:19](=[CH2:18])[C:20](=[O:21])[O:1]1

Participants

6

Reactant 2

HCID 3106202-(Bromomethyl)acrylic acid ethyl esterHCID 138428584-(2-Oxopropoxy)-2H-1-benzopyran-2-one

Product 1

HCID 3815134-((2-Methyl-4-methylene-5-oxotetrahydro-2-furanyl)methoxy)-2H-chromen-2-oneYield 76.4%

Reagents, catalysts & solvents 3

HCID 785HydroquinoneCatalystHCID 23994ZincCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 1a (0.655 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 reflued under nitrogen atmosphere for 36 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 (0.656 g, 76.4%) as a pale yellow crystal. mp: 161°-162° C.; IR(KBr) νmax : 1766, 1703, 1627; UV (CHCl3) λmax (log ε): 306 (3.79), 276 (4.01), 266 (4.05); 1H-NMR (CDCl3): δ1.64 (s, 3H, 5'-CH3), 2.88 (dt, 1H, 4'-H), 3.19 (dt, 1H, 4'-H), 4.08, 4.20 (two d, 2H, OCH2), 5.67 (s, 1H, 3-H), 5.75 (t, 1H, vinylic H), 6.38 (t, 1H, vinylic H), 7.12-7.33 (m, 2H, 6 and 8-H), 7.51-7.65 (m, 2H, 5 and 7-H). Anal. Calcd for C16H14O5 : C, 67.13; H, 4.93. Found: C, 67.14; H, 5.01.

Workup

  1. temperatureAfter cooling it
  2. extractionextracted with CH2Cl2 (75 ml×3)
  3. washwashed with saline
  4. dry with materialdried over Na2SO4
  5. customevaporated
  6. customto give a residual solid which
  7. customwas crystallized from ethyl acetate

Sources & evidence

ORD record
ord-2e109582e2ca4383acb715732cbb8fe6
Source dataset
uspto-grants-1997_07
Patent number
US05646164

Reaction notes

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