Phosphorus oxybromide → 4-Bromo-2-(2,6-dichlorophenyl)-7-fluoro-2H-pyrazolo[4,3-c]pyridine

HRID 626723Notes

Reaction equation

HRID 626723 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([Cl:8])[C:3]=1[N:9]1[CH:19]=[C:12]2[CH:13]=[N+:14]([O-])[CH:15]=[C:16]([F:17])[C:11]2=[N:10]1.P(Br)(Br)([Br:22])=O>ClCCCl>[Br:22][C:13]1[C:12]2=[CH:19][N:9]([C:3]3[C:2]([Cl:1])=[CH:7][CH:6]=[CH:5][C:4]=3[Cl:8])[N:10]=[C:11]2[C:16]([F:17])=[CH:15][N:14]=1

Participants

4

Reactant 2

HCID 24613Phosphorus oxybromideHCID 696712512-(2,6-Dichlorophenyl)-7-fluoro-2H-pyrazolo[4,3-c]pyridine 5-oxide

Product 1

HCID 866970564-Bromo-2-(2,6-dichlorophenyl)-7-fluoro-2H-pyrazolo[4,3-c]pyridineYield 31%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

To a cooled (0° C.) solution of 2-(2,6-dichlorophenyl)-7-fluoro-2H-pyrazolo[4,3-c]pyridine 5-oxide (2.5 g, 8.4 mmol) in DCE (55 mL) under nitrogen was added phosphorous oxybromide (7.2 g, 25.2 mmol). The reaction mixture was stirred for 30 minutes, warmed to room temperature, and stirred for a further 4 hours. The reaction was quenched with sodium carbonate (sat. aq.) and the layers were partitioned. The organic layer was washed with brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The resultant residue was purified by silica gel flash chromatography (20% ethyl acetate in cyclohexane) to afford the title compound as a white solid (927 mg, 31% yield). LCMS (Method D): RT=3.74 min, m/z: 360 [M+H+].

Workup

  1. stirringstirred for a further 4 hours
  2. customThe reaction was quenched with sodium carbonate (sat. aq.)
  3. customthe layers were partitioned
  4. washThe organic layer was washed with brine
  5. dry with materialdried over anhydrous sodium sulfate
  6. concentrationconcentrated under reduced pressure
  7. customThe resultant residue was purified by silica gel flash chromatography (20% ethyl acetate in cyclohexane)

Sources & evidence

ORD record
ord-71bec91de8444363bf5f195eada85db9
Source dataset
uspto-grants-2016_04
Patent number
US09309240B2

Reaction notes

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