Hydrochloric Acid → 1-(4-Chlorophenyl)-1H-pyrazol-5-amine

HRID 459672Notes

Reaction equation

HRID 459672 reaction equation
Cl.[Cl:2][C:3]1[CH:8]=[CH:7][C:6]([NH:9][NH2:10])=[CH:5][CH:4]=1.Cl.CN([C:15](=[CH2:18])[C:16]#[N:17])C>CO>[NH2:17][C:16]1[N:9]([C:6]2[CH:7]=[CH:8][C:3]([Cl:2])=[CH:4][CH:5]=2)[N:10]=[CH:18][CH:15]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 71600Hydrazine, (4-chlorophenyl)-, hydrochloride (1:1)HCID 12896101Dimethylaminoacrylonitrile

Product 1

HCID 122043801-(4-Chlorophenyl)-1H-pyrazol-5-amine

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

21.5 g (0.12 mol) of 4-chlorophenylhydrazine hydrochloride was suspended in 150 mL of methanol, 5 mL of concentrated hydrochloric acid was added, and the mixture was heated at reflux, which gave a clear, yellow-brown solution. To this solution was added dropwise 11.5 g (0.12 mol) of dimethylaminoacrylonitrile over a period of 30 minutes. After 1.5 h at reflux, most of the solvent was removed under vacuum. The remaining residue was taken up in 40 mL of dimethylformamide, and 9 mL of concentrated ammonia solution was added at room temperature. The resulting white precipitate was filtered off and discarded. The clear filtrate was used in Step 10.2 without further purification.

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux
  3. customwhich gave a clear, yellow-brown solution
  4. temperatureAfter 1.5 h at reflux, most of the solvent
  5. customwas removed under vacuum
  6. addition9 mL of concentrated ammonia solution was added at room temperature
  7. filtrationThe resulting white precipitate was filtered off
  8. customThe clear filtrate was used in Step 10.2 without further purification

Sources & evidence

ORD record
ord-bce34b5d0e8f40b482936010394f4599
Source dataset
uspto-grants-2007_03
Patent number
US07195649B2

Reaction notes

Loading…