m-Chlorophenylhydrazine hydrochloride → 1-(3-chlorophenyl)-3-methyl-1H-pyrazol-5-amine

HRID 1054303Notes

Reaction equation

HRID 1054303 reaction equation
[CH3:1]/[C:2](/N)=[CH:3]\[C:4]#[N:5].Cl.[Cl:8][C:9]1[CH:10]=[C:11]([NH:15][NH2:16])[CH:12]=[CH:13][CH:14]=1>Cl.O>[Cl:8][C:9]1[CH:10]=[C:11]([N:15]2[C:4]([NH2:5])=[CH:3][C:2]([CH3:1])=[N:16]2)[CH:12]=[CH:13][CH:14]=1

Participants

5

Reactant 2

HCID 75331m-Chlorophenylhydrazine hydrochlorideHCID 53247203-Aminocrotonitrile

Product 1

HCID 18106301-(3-chlorophenyl)-3-methyl-1H-pyrazol-5-amineYield 20.1%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 962WaterSolvent

Procedure

(see, e.g., Ganesan, A., et al., Journal of Organic Chemistry 1993, 58, 6155-6157). A solution of 3-aminocrotonitrile (mixture of cis and trans) (1.50 g, 17.5 mmol) and 3-chlorophenylhydrazine hydrochloride (3.0 g, 16.2 mmol) in 25 mL of 1N HCl was heated to reflux for 3 h under nitrogen. The reaction mixture was diluted with H2O (30 mL) and extracted with EtOAc (20 mL×2). The combined organic layers were washed with brine, dried (Na2SO4), filtered, and concentrated under reduced pressure. The crude was recrystallized from hot iPrOH to give the title compound (677 mg, 20%) as a beige fluffy solid. 1H NMR (500 MHz, CDCl3) δ 7.62 (s, 1H), 7.48 (d, J=8.0 Hz, 1H), 7.37 (t, J=8.0 Hz, 1H), 7.28 (d, J=9.5 Hz, 1H), 5.46 (s, 1H), 2.22 (s, 3H). 13C NMR (125 MHz, CDCl3) δ 149.95, 145.30, 139.87, 135.05, 130.32, 126.86, 123.67, 121.28, 91.41, 13.89.

Workup

  1. temperatureto reflux for 3 h under nitrogen
  2. extractionextracted with EtOAc (20 mL×2)
  3. washThe combined organic layers were washed with brine
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe crude was recrystallized from hot iPrOH

Sources & evidence

ORD record
ord-3a1a8a5c54e94435b4d9ddf21c5ea648
Source dataset
uspto-grants-2016_07
Patent number
US09394303B2

Reaction notes

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