Nitric Acid → 5-Nitro-2-oxindole

HRID 24308

Reaction equation

HRID 24308 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 25 mL concentrated sulfuric acid and the mixture maintained at −10 to −15° C. while 2.1 mL of fuming nitric acid was added dropwise. After the addition of the nitric acid the reaction mixture was stirred at 0° C. for 0.5 hr and poured into ice-water. The precipitate was collected by filtration, washed with water and crystallized from 50% acetic acid. The 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. filtrationThe precipitate was collected by filtration
  3. washwashed with water
  4. customcrystallized from 50% acetic acid
  5. filtrationThe crystalline product was then filtered
  6. washwashed with water
  7. customdried under vacuum

Sources & evidence

ORD record
ord-c37358cc8853498c815ec34c29a5ddad
Source dataset
uspto-grants-2005_02
Patent number
US06855730B2

Linked notes

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