N-Fluorobenzenesulfonimide → 5-Fluoro-1-[tri(propan-2-yl)silyl]-1H-pyrrolo[2,3-b]pyridine

HRID 2108738Notes

Reaction equation

HRID 2108738 reaction equation
C([Li])CCC.Br[C:7]1[CH:8]=[C:9]2[CH:15]=[CH:14][N:13]([Si:16]([CH:23]([CH3:25])[CH3:24])([CH:20]([CH3:22])[CH3:21])[CH:17]([CH3:19])[CH3:18])[C:10]2=[N:11][CH:12]=1.C1C=CC(S(N(S(C2C=CC=CC=2)(=O)=O)[F:36])(=O)=O)=CC=1>C1COCC1.CCCCCC>[F:36][C:7]1[CH:8]=[C:9]2[CH:15]=[CH:14][N:13]([Si:16]([CH:23]([CH3:25])[CH3:24])([CH:20]([CH3:22])[CH3:21])[CH:17]([CH3:19])[CH3:18])[C:10]2=[N:11][CH:12]=1

Participants

6

Reactant 3

HCID 588007N-FluorobenzenesulfonimideHCID 242292235-Bromo-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridineHCID 178418339Butyllithium

Product 1

HCID 242292265-Fluoro-1-[tri(propan-2-yl)silyl]-1H-pyrrolo[2,3-b]pyridineYield 50.2%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Conditions

Temperature
-78 °C

Procedure

2.5M Butyl lithium (4.4 mL, 10.8 mmol) was added dropwise to a stirred solution of 5-bromo-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine (2.55 g, 7.23 mmol) in THF (65 mL) over 10 min at −78° C. under nitrogen in three necked flask. The resulting solution was stirred at −78° C. for 1 h and solid N-fluorobenzenesulfonimide (2.84 g, 9.03 mmol) was added in one portion and stirred at −78° C. for 2 h. The solvent was evaporated and the crude material was dissolved in water (50 mL) and extracted with EtOAc (3×25 mL). The organic extract was dried and concentrated under reduced pressure to give a residue which was suspended in hexane (5 mL) and filtered. The filtrate was chromatographed (Biotage HPFC) on silica gel eluting with hexane to give 5-fluoro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine (1.06 g, 50.2%) as a viscous oil.; Mass Spec.; MS 293 (M+1); 1H NMR(CDCl3,500 MHz) 8.11(d,1H), 7.51(dd,1H), 7.34(d,1H), 6.50(d,1H), 1.84(q,3H), 1.10(d,18H).

Workup

  1. stirringstirred at −78° C. for 2 h
  2. customThe solvent was evaporated
  3. dissolutionthe crude material was dissolved in water (50 mL)
  4. extractionextracted with EtOAc (3×25 mL)
  5. extractionThe organic extract
  6. customwas dried
  7. concentrationconcentrated under reduced pressure
  8. customto give a residue which
  9. filtrationfiltered
  10. customThe filtrate was chromatographed (Biotage HPFC) on silica gel eluting with hexane

Sources & evidence

ORD record
ord-73d3c8863c3947d0b90466c6302ee66d
Source dataset
uspto-grants-2009_04
Patent number
US07514448B2

Reaction notes

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