Hydrochloric Acid → 4-cyano-2,2-bisfluoromethyl-6-nitro-2H-1-benzopyran

HRID 264836Notes

Reaction equation

HRID 264836 reaction equation
[F:1][CH2:2][C:3]1([CH2:17][F:18])[CH2:8][C:7](=O)[C:6]2[CH:10]=[C:11]([N+:14]([O-:16])=[O:15])[CH:12]=[CH:13][C:5]=2[O:4]1.C[Si]([C:23]#[N:24])(C)C.P(Cl)(Cl)(Cl)=O.Cl>[I-].[Zn+2].[I-].N1C=CC=CC=1.C1C=CC=CC=1>[C:23]([C:7]1[C:6]2[CH:10]=[C:11]([N+:14]([O-:16])=[O:15])[CH:12]=[CH:13][C:5]=2[O:4][C:3]([CH2:17][F:18])([CH2:2][F:1])[CH:8]=1)#[N:24]

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 24813Phosphorus oxychlorideHCID 82115Trimethylsilyl cyanideHCID 155458532,2-bisfluoromethyl-3,4-dihydro-6-nitro-2H-1-benzopyran-4-one

Product 1

HCID 211949804-cyano-2,2-bisfluoromethyl-6-nitro-2H-1-benzopyran

Reagents, catalysts & solvents 3

HCID 9883512zinc(II)iodideCatalystHCID 241BenzeneSolventHCID 1049PyridineSolvent

Procedure

To a mixture of 4.05 g of 2,2-bis(fluoromethyl)-3,4-dihydro-6-nitro-2H-1-benzopyran-4-one and 10 ml of dried benzene was added 2.52 ml of trimethylsilyl cyanide with stirring under ice-cooling. 0.82 g of zinc iodide was added therein and the mixture was stirred at room temperature for 12 hours. Further, 8 ml of pyridine and 4.41 ml of phosphorus oxychloride were added therein and the resultant mixture was refluxed with heating for 6 hours. Ice water was added to the residue and it was acidified to be hydrochloric acid and it was extracted with methylene chloride. An organic layer was washed with water and dried, and the solvent was distilled. The obtained residue was purified according to silica gel column chromatography (developing solution, CH2Cl2 :hexane=7:3) to obtain 0.99 g of 4-cyano-2,2-bis(fluoromethyl)-6-nitro-2H-1-benzopyran with a melting point of 136°-137° C.

Workup

  1. temperaturecooling
  2. stirringthe mixture was stirred at room temperature for 12 hours
  3. temperaturewith heating for 6 hours
  4. extractionwas extracted with methylene chloride
  5. washAn organic layer was washed with water
  6. customdried
  7. distillationthe solvent was distilled
  8. customThe obtained residue was purified

Sources & evidence

ORD record
ord-07154dedc489443eb097a9500e574f78
Source dataset
uspto-grants-1997_07
Patent number
US05646308

Reaction notes

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