Water → 5-Nitroindole-2-carboxylic acid

HRID 1484021Notes

Reaction equation

HRID 1484021 reaction equation
C([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([N+:15]([O-:17])=[O:16])=[CH:10][CH:9]=2)=[O:5])C.[OH-].[K+].O>CO.O>[N+:15]([C:11]1[CH:12]=[C:13]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6]([C:4]([OH:5])=[O:3])=[CH:14]2)([O-:17])=[O:16]

Participants

5

Reactant 3

HCID 962WaterHCID 14797Potassium HydroxideHCID 280312Ethyl 5-nitro-1H-indole-2-carboxylate

Product 1

HCID 3512915-Nitroindole-2-carboxylic acidYield 108.4%

Reagents, catalysts & solvents 1

HCID 22242641Methanol--water (1/1)Solvent

Procedure

5-Nitro-1H-indole-2-carboxylic acid ethyl ester 15 (194 mg, 0.83 mmol) and KOH (342 mg, 5.25 mmol) were stirred in MeOH/water (8 mL/4 mL) at room temperature for 21.5 h. More water was added to dilute the solution. The mixture was concentrated to remove the organic solvent. The remaining solution was washed with DCM (100 mL). The aqueous solution was adjusted with 1 N HCl to pH 2.9, extracted with EtOAc (2×15 mL). The combined EtOAc extraction was washed with brine, dried over sodium sulfate, concentrated to afford the product as solid (185.5 mg, 97% yield). 1H-NMR (DMSO-d6): 8.718 (d, J=2.0-2.5 Hz, 1H, Ar—H), 8.116 (dd, J=2.0-2.5 Hz and 9.0-9.5 Hz, 1H, Ar—H), 7.583 (d, J=9.0-9.5 Hz, 1H, Ar—H), 7.378 (d, J=1.5 Hz, 1H, Ar—H). LC-MS: 207.1 (MH+).

Workup

  1. additionto dilute the solution
  2. concentrationThe mixture was concentrated
  3. customto remove the organic solvent
  4. washThe remaining solution was washed with DCM (100 mL)
  5. extractionextracted with EtOAc (2×15 mL)
  6. extractionThe combined EtOAc extraction
  7. washwas washed with brine
  8. dry with materialdried over sodium sulfate
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-5f3bd2a22a874bfba1ee0f42a6050a3e
Source dataset
uspto-grants-2016_08
Patent number
US09421204B2

Reaction notes

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