Water → 5-Nitroindole-2-carboxylic acid

HRID 587416Notes

Reaction equation

HRID 587416 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, 1 H, Ar—H), 8.116 (dd, J=2.0-2.5 Hz and 9.0-9.5 Hz, 1 H, Ar—H), 7.583 (d, J=9.0-9.5 Hz, 1 H, Ar—H), 7.378 (d, J=1.5 Hz, 1 H, 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-ddba2e0f6d0f40a7a31dd524d8a31980
Source dataset
uspto-grants-2016_01
Patent number
US09226970B2

Reaction notes

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