Nitric Acid → 3-(2,4-Difluoro-5-nitrophenyl)-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine

HRID 849922Notes

Reaction equation

HRID 849922 reaction equation
S(=O)(=O)(O)O.[F:6][C:7]1[CH:12]=[C:11]([F:13])[CH:10]=[CH:9][C:8]=1[C:14]1[C:15](=[O:25])[N:16]([CH3:24])[C:17]([C:20]([F:23])([F:22])[F:21])=[CH:18][N:19]=1.[N+:26]([O-])([OH:28])=[O:27]>>[F:6][C:7]1[CH:12]=[C:11]([F:13])[C:10]([N+:26]([O-:28])=[O:27])=[CH:9][C:8]=1[C:14]1[C:15](=[O:25])[N:16]([CH3:24])[C:17]([C:20]([F:21])([F:23])[F:22])=[CH:18][N:19]=1

Participants

4

Reactant 3

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 193655123-(2,4-Difluorophenyl)-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine2×

Product 1

HCID 193654873-(2,4-Difluoro-5-nitrophenyl)-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazineYield 96%

Procedure

To 85 ml of concentrated sulfuric acid was added 7.0 g of 3-(2,4-difluorophenyl)-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (present compound 1-10) at 5° C. Furthermore, 9 ml of 70% nitric acid was added, and the mixture was stirred at 5° to 10° C. for 8 hours. After completion of the reaction, the reaction mixture was added to ice water, followed by extraction with ethyl acetate. The organic layer was washed with water and then saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography, which afforded 7.76 g (yield, 96%) of 3-(2,4-difluoro-5-nitrophenyl)-1-methyl-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (present compound 1-16; m.p., 93.2° C.).

Workup

  1. customAfter completion of the reaction
  2. extractionfollowed by extraction with ethyl acetate
  3. washThe organic layer was washed with water
  4. dry with materialsaturated sodium chloride solution, dried with anhydrous magnesium sulfate
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-733e7561f8a74b25b190247731f17ae9
Source dataset
uspto-grants-2000_01
Patent number
US06015774

Reaction notes

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