Hydrochloric Acid → 7-nitro-1H-indole-2-carboxylic acid

HRID 336462Notes

Reaction equation

HRID 336462 reaction equation
C[O:2][C:3]([C:5]1[NH:6][C:7]2[C:12]([CH:13]=1)=[CH:11][CH:10]=[CH:9][C:8]=2[N+:14]([O-:16])=[O:15])=[O:4].[OH-].[Na+].Cl>O1CCCC1.O>[N+:14]([C:8]1[CH:9]=[CH:10][CH:11]=[C:12]2[C:7]=1[NH:6][C:5]([C:3]([OH:4])=[O:2])=[CH:13]2)([O-:16])=[O:15]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 18550960Methyl 7-nitro-1h-indole-2-carboxylate

Product 1

HCID 814097-nitro-1H-indole-2-carboxylic acidYield 99%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

7-Nitro-1H-indole-2-carboxylic acid methyl ester (13 g, 59 mmol) prepared in Preparation 17 was dissolved in a solvent mixture of tetrahydrofuran and water (1:1, 300 mL), to which was added 1N aqueous sodium hydroxide solution (180 mL, 177 mmol). The mixture was stirred for 3 h at room temperature, and excess 6N hydrochloric acid solution was added thereto. The reaction mixture was extracted with ethyl acetate. The extract was washed with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and filtered. The solvent was removed by distillation under reduced pressure, and the residue was dried to give the title compound (12 g, Yield 99%).

Workup

  1. extractionThe reaction mixture was extracted with ethyl acetate
  2. washThe extract was washed with saturated aqueous sodium chloride solution
  3. dry with materialdried over anhydrous magnesium sulfate
  4. filtrationfiltered
  5. customThe solvent was removed by distillation under reduced pressure
  6. customthe residue was dried

Sources & evidence

ORD record
ord-7941d0f9ded446928411507dc84e7ceb
Source dataset
uspto-grants-2014_11
Patent number
US08889691B2

Reaction notes

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