Sulfuric Acid → 5-Amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-pyrazole

HRID 622595

Reaction equation

HRID 622595 reaction equation
Cl[C:2](=[CH2:5])[C:3]#[N:4].[Cl:6][C:7]1[CH:12]=[C:11]([C:13]([F:16])([F:15])[F:14])[CH:10]=[C:9]([Cl:17])[C:8]=1[NH:18][NH2:19].C(N(CC(O)=O)CC(O)=O)CN(CC([O-])=O)CC([O-])=O.[Na+].[Na+].S(=O)(=O)(O)O.C(=O)([O-])[O-].[Na+].[Na+]>CO>[NH2:4][C:3]1[N:18]([C:8]2[C:7]([Cl:6])=[CH:12][C:11]([C:13]([F:14])([F:16])[F:15])=[CH:10][C:9]=2[Cl:17])[N:19]=[CH:5][CH:2]=1

Participants

7

Reactant 5

HCID 1118Sulfuric AcidHCID 10340Sodium CarbonateHCID 701982-ChloroacrylonitrileHCID 688223[2,6-Dichloro-4-(trifluoromethyl)phenyl]hydrazineHCID 13020083Ethylenediaminetetraacetic acid disodium salt

Product 1

HCID 135571095-Amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-pyrazoleYield 96%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

25 ml (27.6 g/0.3 mol) of 2-chloro-acrylonitrile are added dropwise to 24.5 g (0.1 mol) of 2,6-dichloro-4-trifluoromethylphenylhydrazine and 20 mg of disodium ethylenediamine-tetraacetate (Titriplex III) in 150 ml of methanol at the reflux temperature. When the addition has ended, the mixture is heated at the reflux temperature for a further 8 hours, 9 ml (0.16 mol) of 96% strength sulphuric acid are added dropwise and the mixture is heated at the reflux temperature for a further 6 hours. 33.5 g (0.3 mol) of anhydrous sodium carbonate are added to the cooled reaction mixture. After 4 hours, the solvent is removed in vacuo, the residue is taken up in 500 ml of water and the mixture is stirred at room temperature for 10 hours. The precipitate which has separated out is filtered off, rinsed with water and dried in vacuo at 50° C. 28.5 (96% of theory) of 5-amino- 1-(2,6-dichloro-4-trifluoromethylphenyl)-pyrazole of melting point 103°-105° C. are obtained.

Workup

  1. additionWhen the addition
  2. temperaturethe mixture is heated at the reflux temperature for a further 8 hours
  3. temperaturethe mixture is heated at the reflux temperature for a further 6 hours
  4. customthe solvent is removed in vacuo
  5. customThe precipitate which has separated out
  6. filtrationis filtered off
  7. washrinsed with water
  8. customdried in vacuo at 50° C

Sources & evidence

ORD record
ord-2f9c91db730d4cb688408c810237d2d2
Source dataset
uspto-grants-1988_09
Patent number
US04772309

Linked notes

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