Methyl 4-amino-3-methylbenzoate → Methyl 1H-indazole-5-carboxylate

HRID 1269707Notes

Reaction equation

HRID 1269707 reaction equation
[N:1]([O-])=O.[Na+].[NH2:5][C:6]1[CH:15]=[CH:14][C:9]([C:10]([O:12][CH3:13])=[O:11])=[CH:8][C:7]=1[CH3:16]>O.C(O)(=O)C>[NH:5]1[C:6]2[C:7](=[CH:8][C:9]([C:10]([O:12][CH3:13])=[O:11])=[CH:14][CH:15]=2)[CH:16]=[N:1]1

Participants

5

Reactant 2

HCID 2736799Methyl 4-amino-3-methylbenzoateHCID 23668193Sodium Nitrite

Product 1

HCID 22260640Methyl 1H-indazole-5-carboxylateYield 30.3%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

A solution of sodium nitrite (836 mg, 59.1 mmol) in water (2 ml) was added to a solution of methyl 4-amino-3-methylbenzoate (2.00 g, 12.1 mmol) in acetic acid (80 ml) at room temperature and stirred at room temperature for 5 hours. The reaction solution was concentrated and the resulting residue was diluted with chloroform and washed with a 5% aqueous sodium hydrogencarbonate solution and then a saturated aqueous sodium chloride solution. The organic layer was dried over anhydrous sodium sulfate and distilled under reduced pressure to remove the solvent, and the resulting residue was purified by a silica gel column chromatography (eluent: hexane/ethyl acetate=3/1) to obtain methyl 1H-indazole-5-carboxylate (645 mg, 30%).

Workup

  1. concentrationThe reaction solution was concentrated
  2. additionthe resulting residue was diluted with chloroform
  3. washwashed with a 5% aqueous sodium hydrogencarbonate solution
  4. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  5. distillationdistilled under reduced pressure
  6. customto remove the solvent
  7. customthe resulting residue was purified by a silica gel column chromatography (eluent: hexane/ethyl acetate=3/1)

Sources & evidence

ORD record
ord-9c91d76431d440fa837b74704e168866
Source dataset
uspto-grants-2007_04
Patent number
US07199147B2

Reaction notes

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