Sulfuric Acid → 6H-thiazolo[5,4-e]indole-7,8-dione

HRID 1700140Notes

Reaction equation

HRID 1700140 reaction equation
S(=O)(=O)(O)[OH:2].[S:6]1[C:10]2[CH:11]=[C:12]([NH:15][C:16](=[O:20])[CH:17]=NO)[CH:13]=[CH:14][C:9]=2[N:8]=[CH:7]1>O>[S:6]1[C:10]2[C:9](=[CH:14][CH:13]=[C:12]3[C:11]=2[C:17](=[O:2])[C:16](=[O:20])[NH:15]3)[N:8]=[CH:7]1

Participants

4

Reactant 2

HCID 1118Sulfuric Acid2×HCID 85408681N-benzothiazol-6-yl-2-hydroxyimino-acetamide

Product 1

HCID 117457566H-thiazolo[5,4-e]indole-7,8-dioneYield 46%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a 1-L 3-neck round bottom flask was placed a magnetic stir bar and 100 ml of concentrated sulfuric acid. The flask was fitted with a thermometer to monitor the temperature of the reaction. The sulfuric acid was heated to 100° C., and 10.0 g (45.2 mmol) of N-benzothiazol-6-yl-2-hydroxyimino-acetamide was added slowly. The solution was heated for ˜1 h, and the reaction mixture was poured into 750 g of ice and water. The residual reaction mixture in the reaction vessel was washed out with an additional 20 mL of cold water. The aqueous slurry was stirred for about 1 h and filtered. The solid was washed thoroughly with water, filtered, and air dried to yield 4.3 g (46%) of 6-H-1-thia-3,6-diaza-as-indacen-7,8-dione:

Workup

  1. customTo a 1-L 3-neck round bottom flask was placed
  2. customThe flask was fitted with a thermometer
  3. customthe temperature of the reaction
  4. temperatureThe solution was heated for ˜1 h
  5. customThe residual reaction mixture in the reaction vessel
  6. washwas washed out with an additional 20 mL of cold water
  7. filtrationfiltered
  8. washThe solid was washed thoroughly with water
  9. filtrationfiltered
  10. customair dried

Sources & evidence

ORD record
ord-b0b382ab1c084c11aed7d41d97615232
Source dataset
uspto-grants-2002_02
Patent number
US06350747B1

Reaction notes

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