Nitric Acid → 5-Nitro-2-oxindole

HRID 1860769Notes

Reaction equation

HRID 1860769 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:5]=[C:4]2[C:9](=[CH:8][CH:7]=1)[NH:1][C:2](=[O:10])[CH2:3]2)([O-:13])=[O:12]

Participants

4

Reactant 2

HCID 944Nitric Acid2×HCID 321710Oxindole

Product 1

HCID 2303665-Nitro-2-oxindoleYield 70%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Conditions

Temperature
0 °C

Procedure

2-Oxindole (6.5 g) was dissolved in concentrated sulfuric acid (25 ml) and the mixture maintained at −10 to 15° C. while fuming nitric acid (2.1 ml) was added dropwise. After the addition of the nitric acid the reaction mixture was stirred at 0° C. for 0.5 hour and poured into ice-water. The precipitate which formed was collected by filtration, washed with water and crystallized from 50% acetic acid. The final crystalline product was then filtered, washed with water and dried under vacuum to give 6.3 g (70%) of 5-nitro-2-oxindole.

Workup

  1. additionwas added dropwise
  2. customThe precipitate which formed
  3. filtrationwas collected by filtration
  4. washwashed with water
  5. customcrystallized from 50% acetic acid
  6. filtrationThe final crystalline product was then filtered
  7. washwashed with water
  8. customdried under vacuum

Sources & evidence

ORD record
ord-61078976fad04daa97b86d7df77f662c
Source dataset
uspto-grants-2003_03
Patent number
US06531502B1

Reaction notes

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