Hydrazine hydrate (1:1) → Ethyl 3-(4-fluorophenyl)-1h-pyrazole-5-carboxylate

HRID 920705Notes

Reaction equation

HRID 920705 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=O)[CH2:9][C:10](=O)[C:11]([O:13][CH2:14][CH3:15])=[O:12])=[CH:4][CH:3]=1.O.[NH2:19][NH2:20]>C(O)C>[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:9]=[C:10]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[NH:20][N:19]=2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 596593Ethyl 4-(4-fluorophenyl)-2,4-dioxobutanoate

Product 1

HCID 583549Ethyl 3-(4-fluorophenyl)-1h-pyrazole-5-carboxylateYield 67.8%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of Intermediate 1A (120 g, 504 mmol) in ethanol (1200 mL) was added hydrazine monohydrate (25.7 mL, 529 mmol) slowly and the resulting reaction mixture was refluxed for 1 h. Reaction mixture was cooled to RT, poured into ice cold water, and the resultant solid dried under vacuum to afford Intermediate 1B (80 g, 67%). MS(ES): m/z=235 [M+H]+; 1H NMR (300 MHz, CDCl3) δ ppm 7.75 (m, 2H), 7.12 (m, 2H), 7.07 (s, 1H), 4.42 (q, J=7.2 Hz, 2H), 1.42 (t, J=7.2 Hz, 3H).

Workup

  1. customthe resulting reaction mixture
  2. temperaturewas refluxed for 1 h
  3. customReaction mixture
  4. additionpoured into ice cold water
  5. customthe resultant solid dried under vacuum

Sources & evidence

ORD record
ord-0286cad3f3f4430ba4023001bc5a355f
Source dataset
uspto-grants-2016_03
Patent number
US09273058B2

Reaction notes

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