Nitric Acid → 5-Nitro-2H-indol-2-one

HRID 2191455Notes

Reaction equation

HRID 2191455 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][C:2]1=[O:10].[N+:11]([O-])([OH:13])=[O:12]>S(=O)(=O)(O)O>[N+:11]([C:6]1[CH:7]=[CH:8][C:9]2[C:4](=[CH:3][C:2](=[O:10])[N:1]=2)[CH:5]=1)([O-:13])=[O:12]

Participants

4

Reactant 2

HCID 944Nitric AcidHCID 321710Oxindole

Product 1

HCID 467398415-Nitro-2H-indol-2-oneYield 92.4%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

1,3-Dihydro-indol-2-one 30a (20.0 g, 150 mmol) was dissolved in sulfuric acid (100 ml, 98%) in an ice-water bath under stirring, and added dropwise with nitric acid (10 ml, 65%-68%) while maintaining the temperature below 0° C. Upon completion of the addition, the mixture was stirred for 1 hour at 0° C. After thin lay chromatography showed the disappearance of starting materials, the reaction mixture was added with ice and filtered after ice-out. The filter cake was washed with water (20 ml×3), and the resulting solid was recrystallized to obtain the title compound 5-nitro-indol-2-one 30b (25.3 g, yield 92.4%) as an orange solid.

Workup

  1. temperaturewhile maintaining the temperature below 0° C
  2. additionUpon completion of the addition
  3. stirringthe mixture was stirred for 1 hour at 0° C
  4. additionthe reaction mixture was added with ice
  5. filtrationfiltered after ice-out
  6. washThe filter cake was washed with water (20 ml×3)
  7. customthe resulting solid was recrystallized

Sources & evidence

ORD record
ord-faea2d974cc54ffa86d47c301c5b0f7e
Source dataset
uspto-grants-2012_12
Patent number
US08329682B2

Reaction notes

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