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

HRID 1639795Notes

Reaction equation

HRID 1639795 reaction equation
[NH2:1][C:2]1[C:3]([CH3:13])=[C:4]([C:9]([Br:12])=[CH:10][CH:11]=1)[C:5]([O:7][CH3:8])=[O:6].[N:14]([O-])=O.[Na+]>C(O)(=O)C.O>[Br:12][C:9]1[CH:10]=[CH:11][C:2]2[NH:1][N:14]=[CH:13][C:3]=2[C:4]=1[C:5]([O:7][CH3:8])=[O:6]

Participants

5

Reactant 2

HCID 23668193Sodium NitriteHCID 59145915Methyl 3-amino-6-bromo-2-methylbenzoate

Product 1

HCID 59145907Methyl 5-bromo-1H-indazole-4-carboxylateYield 86%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

To a solution of methyl 3-amino-6-bromo-2-methylbenzoate (5.44 g, 22.3 mmol) in acetic acid (110 mL) was added a solution of sodium nitrite (1.69 g, 24.5 mmol) in water (11 mL) at room temperature, and the mixture was stirred for 20 hr. The organic solvent was evaporated under reduced pressure. The residual aqueous solution was diluted with saturated aqueous sodium hydrogen carbonate solution, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, and dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (NH, ethyl acetate/hexane=10/90→30/70) to give the title compound (4.86 g, yield 86%).

Workup

  1. customThe organic solvent was evaporated under reduced pressure
  2. additionThe residual aqueous solution was diluted with saturated aqueous sodium hydrogen carbonate solution
  3. extractionthe mixture was extracted with ethyl acetate
  4. washThe extract was washed with saturated brine
  5. dry with materialdried over anhydrous sodium sulfate
  6. customthe solvent was evaporated under reduced pressure
  7. customThe residue was purified by silica gel column chromatography (NH, ethyl acetate/hexane=10/90→30/70)

Sources & evidence

ORD record
ord-256fe16ff0c446a58455cbfcf34aef88
Source dataset
uspto-grants-2012_02
Patent number
US08110585B2

Reaction notes

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