Pyridine, hydrofluoride (1:1) → 3-Bromo-2-fluoro-1-benzofuran-5-carbaldehyde

HRID 2261110Notes

Reaction equation

HRID 2261110 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([CH:10]=[O:11])=[CH:9][C:4]=2[CH:3]=[CH:2]1.C1C(=O)N([Br:19])C(=O)C1.C1C=CN=CC=1.[FH:26]>CCOCC>[Br:19][C:3]1[C:4]2[CH:9]=[C:8]([CH:10]=[O:11])[CH:7]=[CH:6][C:5]=2[O:1][C:2]=1[F:26]

Participants

5

Reactant 3

HCID 64774Pyridine, hydrofluoride (1:1)HCID 67184N-bromobutanimideHCID 27738751-Benzofuran-5-carbaldehyde

Product 1

HCID 574696783-Bromo-2-fluoro-1-benzofuran-5-carbaldehyde

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

Benzofuran-5-carbaldehyde (100 mg, 0.68 mmol) in ether (1 mL) was added to a cold solution (−78° C.) of NBS (158 mg, 1.3 eq) and pyridinium poly(hydrogen fluoride) 70% (0.850 mL) in ether (4 mL) in a polypropylene tube. The reaction was allowed to warm up to room temperature overnight. The reaction mixture was poured into ice water and extracted with ether. The ether phase was washed with aqueous bicarbonate, dried over sodium sulfate, filtrated and evaporated to give 3-bromo-2-fluoro-benzofuran-5-carbaldehyde (141.6 mg). It was purified on reverse phase HPLC (solvents gradient H2O/CH3CN 0.1% TFA) affording the title compound (62 mg, 37%), which was used in the next step.

Workup

  1. extractionextracted with ether
  2. washThe ether phase was washed with aqueous bicarbonate
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltrated
  5. customevaporated

Sources & evidence

ORD record
ord-ab7994113bbd4ae697950591a61eaa90
Source dataset
uspto-grants-2010_12
Patent number
US07846925B2

Reaction notes

Loading…