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

HRID 1045848Notes

Reaction equation

HRID 1045848 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-d4503c83187c4050908b51912cf35d72
Source dataset
uspto-grants-2013_10
Patent number
US08569307B2

Reaction notes

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