Sulfuric Acid → 5-Methoxyisatin

HRID 1952923Notes

Reaction equation

HRID 1952923 reaction equation
S(=O)(=O)(O)[OH:2].N(=[CH:8][C:9]([NH:11][C:12]1[CH:19]=[CH:18][C:15]([O:16][CH3:17])=[CH:14][CH:13]=1)=[O:10])O>O>[CH3:17][O:16][C:15]1[CH:14]=[C:13]2[C:12](=[CH:19][CH:18]=1)[NH:11][C:9](=[O:10])[C:8]2=[O:2]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 67107914-Methoxyisonitrosoacetanilide

Product 1

HCID 383335-MethoxyisatinYield 65%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
60 °C

Procedure

Concentrated sulfuric acid (45 mL) containing 5 mL of water was warmed to 60° C. and 8.6 g of N-(2-hydroximinoacetyl)anisidine was added in one portion. The stirred mixture was heated to 93° C. for 10 minutes and then allowed to cool to room temperature. The mixture was poured into 500 g of ice and extracted 3 times with ethyl acetate. The combined extracts were dried over anhydrous sodium sulfate and concentrated to give 5.1 g (65% yield) of 5-methoxyisatin as a dark red solid. 5-Methoxyisatin (5.0 g) and 30 mL of hydrazine hydrate were heated to reflux for 15 minutes. The reaction mixture was cooled to room temperature and 50 mL of water was added. The mixture was extracted 3 times with 25 mL of ethyl acetate each time, the organic layers combined, dried over anhydrous sodium sulfate and concentrated to give a yellow solid.

Workup

  1. temperatureThe stirred mixture was heated to 93° C. for 10 minutes
  2. temperatureto cool to room temperature
  3. extractionextracted 3 times with ethyl acetate
  4. dry with materialThe combined extracts were dried over anhydrous sodium sulfate
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-6d271bda69d5404981e10687e3c2fe43
Source dataset
uspto-grants-2000_09
Patent number
US06114371

Reaction notes

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