Nitric Acid → 6-Fluoro-3-methyl-5-nitro-1,2-benzisoxazole

HRID 636039Notes

Reaction equation

HRID 636039 reaction equation
[F:1][C:2]1[CH:11]=[CH:10][C:5]2[C:6]([CH3:9])=[N:7][O:8][C:4]=2[CH:3]=1.[N+:12]([O-])([OH:14])=[O:13]>S(=O)(=O)(O)O>[F:1][C:2]1[C:11]([N+:12]([O-:14])=[O:13])=[CH:10][C:5]2[C:6]([CH3:9])=[N:7][O:8][C:4]=2[CH:3]=1

Participants

4

Reactant 2

HCID 944Nitric Acid2×HCID 219784096-Fluoro-3-methyl-1,2-benzoxazole

Product 1

HCID 183145006-Fluoro-3-methyl-5-nitro-1,2-benzisoxazole

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

A mixture of 6-fluoro-3-methyl-1,2-benzisoxazole (23.5 g, 0.156 mol) in concentrated sulfuric acid is cooled with an ice-bath, treated dropwise with 90% nitric acid (8.50 mL) while maintaining the reaction mixture temperature below 15° C., stirred for one hour at ice-bath temperature, treated with additional 90% nitric acid (5.80 mL), warmed to and stirred at room temperature overnight, and poured onto ice. The resultant aqueous mixture is filtered to obtain a solid. The solid is air-dried and dissolved in methylene chloride. The resultant organic solution is dried over anhydrous magnesium sulfate, diluted with hexanes, and filtered to give the title product as a purple solid which is identified by 1H NMR spectral analysis.

Workup

  1. temperatureis cooled with an ice-bath
  2. temperaturewhile maintaining the reaction mixture temperature below 15° C.
  3. temperaturewarmed to and
  4. stirringstirred at room temperature overnight
  5. additionpoured onto ice
  6. filtrationThe resultant aqueous mixture is filtered
  7. customto obtain a solid
  8. customThe solid is air-dried
  9. dissolutiondissolved in methylene chloride
  10. dry with materialThe resultant organic solution is dried over anhydrous magnesium sulfate
  11. additiondiluted with hexanes
  12. filtrationfiltered

Sources & evidence

ORD record
ord-47e67f06f2284c999edb24bb6614f394
Source dataset
uspto-grants-2001_02
Patent number
US06191275B1

Reaction notes

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