Pyridine → Benzofuran-6-YL trifluoromethanesulfonate

HRID 869865Notes

Reaction equation

HRID 869865 reaction equation
[O:1]1[C:5]2[CH:6]=[C:7]([OH:10])[CH:8]=[CH:9][C:4]=2[CH:3]=[CH:2]1.N1C=CC=CC=1.[O:17](S(C(F)(F)F)(=O)=O)[S:18]([C:21]([F:24])([F:23])[F:22])(=O)=[O:19]>ClCCl.O>[F:22][C:21]([F:24])([F:23])[S:18]([O:10][C:7]1[CH:8]=[CH:9][C:4]2[CH:3]=[CH:2][O:1][C:5]=2[CH:6]=1)(=[O:19])=[O:17]

Participants

6

Reactant 3

HCID 1049PyridineHCID 67749Trifluoromethanesulfonic anhydrideHCID 1288446-Hydroxybenzofuran

Product 1

HCID 11357589Benzofuran-6-YL trifluoromethanesulfonateYield 88.7%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

To a stirred solution of benzofuran-6-ol (17.0 g, 127 mmol) in pyridine (20 g, 254 mmol) and dichloromethane (200 mL) was added Tf2O (53.7 g, 190 mmol). The reaction mixture was stirred at room temperature for 16 h. The reaction mixture was diluted with water, and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated to afford a crude product that was purified by column chromatography on silica gel (5-10% ethyl acetate in petroleum ether) to afford benzofuran-6-yl trifluoromethanesulfonate (30.0 g, 88.0% yield). 1H NMR (300 MHz, CDCl3) δ: 7.72 (d, J=2.1, 1H), 7.67 (d, J=8.7, 1H), 7.48 (d, J=1.5, 1H), 7.19 (dd, J=8.7, 2.1, 1H), 6.82-6.91 (m, 1H).

Workup

  1. extractionextracted with ethyl acetate
  2. washThe combined organic layers were washed with brine
  3. dry with materialdried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customto afford a crude product that
  7. customwas purified by column chromatography on silica gel (5-10% ethyl acetate in petroleum ether)

Sources & evidence

ORD record
ord-af78f512aeda49818bd7f5d2a3e725b1
Source dataset
uspto-grants-2015_03
Patent number
US08969386B2

Reaction notes

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