Hydrochloric Acid → Ethyl 3-[4-(trifluoromethyl)phenyl]-1H-pyrazole-5-carboxylate

HRID 1295095Notes

Reaction equation

HRID 1295095 reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[CH:8][C:7]([C:10]([F:13])([F:12])[F:11])=[CH:6][CH:5]=1)=O.[Na].C[O:16][C:17](=O)[C:18](OC)=O.Cl.O.[NH2:25][NH2:26].[CH3:27][CH2:28][OH:29]>O>[CH2:28]([O:29][C:17]([C:18]1[NH:26][N:25]=[C:2]([C:4]2[CH:9]=[CH:8][C:7]([C:10]([F:13])([F:12])[F:11])=[CH:6][CH:5]=2)[CH:1]=1)=[O:16])[CH3:27]

Participants

8

Reactant 6

HCID 313Hydrochloric AcidHCID 702EthanolHCID 11120Dimethyl oxalateHCID 24654Hydrazine hydrate (1:1)HCID 697311-(4-(Trifluoromethyl)phenyl)ethan-1-oneHCID 5360545Sodium

Product 1

HCID 45790237Ethyl 3-[4-(trifluoromethyl)phenyl]-1H-pyrazole-5-carboxylateYield 55.78%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a solution of 4-trifluoromethylacetophenone (10 g, 53.15 mmol) in EtOH (100 mL) was added portionwise sodium ethoxyde (5.43 g, 79.72 mmol) and the mixture was stirred at room temperature during 20 minutes. Dimethyloxalate (8.16 g, 69.09 mmol) was added and the mixture was heated under reflux during 1 hour and then poured into a solution of HCl 1N. After extraction with CH2Cl2, the organic layer was dried over Na2SO4, and concentrated to dryness. The residue was dissolved in EtOH (100 mL), and hydrazine hydrate (3.1 mL, 63.78 mmol) was added dropwise. The mixture was heated under reflux overnight, then poured into water. After extraction with CH2Cl2, the organic layer was dried over Na2SO4, and concentrated to dryness. The solid residue was crystallised from diisopropyloxyde to afford the titled compound as cream crystals (8.42 g, 55.78%).

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux during 1 hour
  3. extractionAfter extraction with CH2Cl2
  4. dry with materialthe organic layer was dried over Na2SO4
  5. concentrationconcentrated to dryness
  6. dissolutionThe residue was dissolved in EtOH (100 mL)
  7. temperatureThe mixture was heated
  8. temperatureunder reflux overnight
  9. extractionAfter extraction with CH2Cl2
  10. dry with materialthe organic layer was dried over Na2SO4
  11. concentrationconcentrated to dryness
  12. customThe solid residue was crystallised from diisopropyloxyde

Sources & evidence

ORD record
ord-c9b7feba426c4a09b99a7be5891afbc1
Source dataset
uspto-grants-2007_07
Patent number
US07241793B2

Reaction notes

Loading…