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

HRID 2173156Notes

Reaction equation

HRID 2173156 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

Reactant 6

HCID 8471TriethylamineHCID 25517Ammonium ChlorideHCID 31297Methanesulfonyl chlorideHCID 70297m-Chloroperbenzoic acidHCID 811841,8-Diazabicyclo(5.4.0)undec-7-eneHCID 666439615-(2-hydroxyethyl)-2-benzofuran-1(3H)-one

Product 1

HCID 595687155-(oxiran-2-yl)-2-benzofuran-1(3H)-one

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6344DichloromethaneSolventHCID 516892Sodium BicarbonateSolvent

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 vacua. 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) 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. 1H NMR (500 MHz, CD3OD) δ 7.84 (d, J=8.0 Hz, 1H), 7.55 (s, 1H), 7.52 (d, J=8.0 Hz, 1H), 5.38 (s, 2H), 4.05 (dd, J=2.6, 3.9 Hz, 1H), 3.21 (dd, J=4.3, 5.4 Hz, 1H), 2.82 (dd, J=2.4, 5.5 Hz, 1H); LC/MS: [(M+1)]+=177.1.

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 vacua
  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) 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-8a1568bd66e447e18570c39302d1fad6
Source dataset
uspto-grants-2015_06
Patent number
US09056859B2

Reaction notes

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