Triethylamine → 5-(oxiran-2-yl)-2-benzofuran-1(3H)-one

HRID 1474180Notes

Reaction equation

HRID 1474180 reaction equation
[OH:1][CH2:2][CH2:3][C:4]1[CH:13]=[CH:12][C:7]2[C:8](=[O:11])[O:9][CH2:10][C:6]=2[CH:5]=1.CCN(CC)CC.CS(Cl)(=O)=O.[Cl-].[NH4+].C1CCN2C(=NCCC2)CC1.ClC1C=CC=C(C(OO)=O)C=1>ClCCl.O.C(=O)(O)[O-].[Na+]>[O:1]1[CH2:2][CH:3]1[C:4]1[CH:13]=[CH:12][C:7]2[C:8](=[O:11])[O:9][CH2:10][C:6]=2[CH:5]=1

Participants

10

Procedure

To a solution of 5-(2-hydroxyethyl)-2-benzofuran-1(3H)-one (0.50 g, 2.8 mmol) and Et3N (0.65 ml, 4.7 mmol) in dichloromethane (5 ml) was added methanesulfonyl chloride (0.24 mL, 3.1 mmol) at 0° C. After 15 min. the reaction mixture was poured into saturated ammonium chloride and extracted with dichloromethane. The combined organics were washed with 1 N HCl, saturated sodium bicarbonate solution, and brine, then dried (MgSO4) and concentrated in vacuo. The residue (LC/MS: [(M+1)]+=257.2; tR=0.45 min) was redissolved in dichloromethane (5 ml) and treated with DBU (0.80 ml, 5.3 mmol) and stirred 2 h. TLC monitoring showed conversion to the olefin. The reaction mixture was diluted with water and extracted with dichloromethane. The combined organics were washed with 1 N HCl, saturated sodium bicarbonate solution, and brine, then dried (MgSO4) and concentrated in vacuo. The resulting olefin (LC/MS: [(M+1)]+=161.2; tR=0.86 min) was dissolved in dichloromethane (5 ml) and treated with meta-chloro perbenzoic acid (0.90 g, 3.7 mmol) at 0° C. After 3 h, the mixture was diluted with saturated sodium bicarbonate solution and extracted twice with dichloromethane. The combined organic extracts were washed with brine, dried (MgSO4), filtered and concentrated in vacuo. The crude epoxide was purified by silica gel column chromatography (5->80% EtOAc:hexane) to provide the 5-oxirane-2-yl-2-benzofuran-1 (3H)-one.

Workup

  1. extractionextracted with dichloromethane
  2. washThe combined organics were washed with 1 N HCl, saturated sodium bicarbonate solution, and brine
  3. dry with materialdried (MgSO4)
  4. concentrationconcentrated in vacuo
  5. dissolutionThe residue (LC/MS: [(M+1)]+=257.2; tR=0.45 min) was redissolved in dichloromethane (5 ml)
  6. extractionextracted with dichloromethane
  7. washThe combined organics were washed with 1 N HCl, saturated sodium bicarbonate solution, and brine
  8. dry with materialdried (MgSO4)
  9. concentrationconcentrated in vacuo
  10. dissolutionThe resulting olefin (LC/MS: [(M+1)]+=161.2; tR=0.86 min) was dissolved in dichloromethane (5 ml)
  11. waitAfter 3 h
  12. extractionextracted twice with dichloromethane
  13. washThe combined organic extracts were washed with brine
  14. dry with materialdried (MgSO4)
  15. filtrationfiltered
  16. concentrationconcentrated in vacuo
  17. customThe crude epoxide was purified by silica gel column chromatography (5->80% EtOAc:hexane)

Sources & evidence

ORD record
ord-62d3d5991a4a4ecbbaf08980cac87e95
Source dataset
uspto-grants-2015_04
Patent number
US09018211B2

Reaction notes

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