Sulfuric Acid → 5-bromo-7-methoxy-2,3-dihydro-1H-indole-2,3-dione

HRID 1052981Notes

Reaction equation

HRID 1052981 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([NH:8][C:9](=[O:13])[CH:10]=NO)=[C:4]([O:14][CH3:15])[CH:3]=1.[OH:16]S(O)(=O)=O>>[Br:1][C:2]1[CH:7]=[C:6]2[C:5](=[C:4]([O:14][CH3:15])[CH:3]=1)[NH:8][C:9](=[O:13])[C:10]2=[O:16]

Participants

3

Reactant 2

HCID 1118Sulfuric AcidHCID 117668132N-(4-bromo-2-methoxyphenyl)-2-(hydroxyimino)acetamide

Product 1

HCID 1176679885-bromo-7-methoxy-2,3-dihydro-1H-indole-2,3-dioneYield 70%

Conditions

Temperature
90 °C

Procedure

To concentrated H2SO4 (30 ml) at 65° C. was added N-(4-bromo-2-methoxyphenyl)-2-(hydroxyimino)acetamide (5.55 g, 20 mmol) portionwise. The mixture was heated at 90° C. for 1.5 h. The mixture was cooled to room temperature, poured onto ice, and stirred for 10 min. The solid was collected by filtration, washed with water, and air dried to afford 5-Bromo-7-methoxyindoline-2,3-dione (3.6 g, crude, 70% yield). This material was used without further purification. 1H NMR (400 MHz, DMSO-d6): δH 7.93 (s, 1H), 7.38 (s, 1H), 3.94 (s, 3H). MS (ESI) m/e [M+1]+ 256, 258.

Workup

  1. temperatureThe mixture was cooled to room temperature
  2. additionpoured onto ice
  3. filtrationThe solid was collected by filtration
  4. washwashed with water, and air
  5. customdried

Sources & evidence

ORD record
ord-035de31e9b8043f4bfda560bf25a3463
Source dataset
uspto-grants-2016_07
Patent number
US09393232B2

Reaction notes

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