Sodium Nitrite → Methyl 5-bromo-6-fluoro-1H-indazole-4-carboxylate

HRID 887781Notes

Reaction equation

HRID 887781 reaction equation
[NH2:1][C:2]1[C:3]([CH3:14])=[C:4]([C:9]([Br:13])=[C:10]([F:12])[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6].[N:15]([O-])=O.[Na+]>C(O)(=O)C.O>[Br:13][C:9]1[C:10]([F:12])=[CH:11][C:2]2[NH:1][N:15]=[CH:14][C:3]=2[C:4]=1[C:5]([O:7][CH3:8])=[O:6]

Participants

5

Reactant 2

HCID 23668193Sodium NitriteHCID 59145869Methyl 3-amino-6-bromo-5-fluoro-2-methylbenzoate

Product 1

HCID 59145874Methyl 5-bromo-6-fluoro-1H-indazole-4-carboxylateYield 52%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

To a solution of methyl 3-amino-6-bromo-5-fluoro-2-methylbenzoate (1.33 g, 5.09 mmol) in acetic acid (25 mL) heated to 50° C. was added a solution of sodium nitrite (369 mg, 5.34 mmol) in water (1 mL), and the mixture was stirred for 1.5 hr and concentrated under reduced pressure. The residue was diluted with ethyl acetate, washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate/hexane=5/95→40/60) to give the title compound (700 mg, yield 52%).

Workup

  1. concentrationconcentrated under reduced pressure
  2. additionThe residue was diluted with ethyl acetate
  3. washwashed with saturated aqueous sodium hydrogen carbonate solution and saturated brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. customThe solvent was evaporated under reduced pressure
  6. customthe residue was purified by silica gel column chromatography (ethyl acetate/hexane=5/95→40/60)

Sources & evidence

ORD record
ord-4403e24138424ed5a15022d6a2ae3d9d
Source dataset
uspto-grants-2012_08
Patent number
US08247429B2

Reaction notes

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