Ethyl orthoformate → 4-Cyano-5-ethoxymethyleneamino-1-(2,3,4-trichlorophenyl)pyrazole

HRID 1249127Notes

Reaction equation

HRID 1249127 reaction equation
[NH2:1][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][C:10]([Cl:13])=[C:9]([Cl:14])[C:8]=2[Cl:15])[N:5]=[CH:4][C:3]=1[C:16]#[N:17].O.C1(C)C=CC(S(O)(=O)=O)=CC=1.[CH2:30]([O:32][CH:33](OCC)OCC)[CH3:31]>>[C:16]([C:3]1[CH:4]=[N:5][N:6]([C:7]2[CH:12]=[CH:11][C:10]([Cl:13])=[C:9]([Cl:14])[C:8]=2[Cl:15])[C:2]=1[N:1]=[CH:33][O:32][CH2:30][CH3:31])#[N:17]

Participants

4

Reactant 3

HCID 31214Ethyl orthoformateHCID 521998p-Toluenesulfonic acid monohydrateHCID 30189015-amino-1-(2,3,4-trichlorophenyl)-1H-pyrazole-4-carbonitrile

Product 1

HCID 539122734-Cyano-5-ethoxymethyleneamino-1-(2,3,4-trichlorophenyl)pyrazole

Procedure

A mixture of 5-amino-4-cyano-1-(2,3,4-trichlorophenyl)pyrazole (10 g) and p-toluenesulphonic acid hydrate (0.1 g) in triethylorthoformate (40 ml) was heated at reflux for 1 hour. After cooling, the reaction mixture was evaporated to dryness. The residue was dissolved in dichloromethane and saturated aqueous sodium bicarbonate solution was added. The organic phase was removed, dried over anhydrous magnesium sulphate and evaporated to give a colourless solid which was recrystallised from a mixture of ethyl acetate and hexane to give 4-cyano-5-ethoxymethyleneamino-1-(2,3,4-trichlorophenyl)pyrazole (11.0 g), m.p. 131°-132° C., in the form of colourless crystals.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 1 hour
  3. temperatureAfter cooling
  4. customthe reaction mixture was evaporated to dryness
  5. dissolutionThe residue was dissolved in dichloromethane
  6. additionsaturated aqueous sodium bicarbonate solution was added
  7. customThe organic phase was removed
  8. dry with materialdried over anhydrous magnesium sulphate
  9. customevaporated
  10. customto give a colourless solid which
  11. customwas recrystallised from a mixture of ethyl acetate and hexane

Sources & evidence

ORD record
ord-eff4620378d0446b9397f7c0eb126e5b
Source dataset
uspto-grants-1986_12
Patent number
US04629495

Reaction notes

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