Acetic Acid → ethyl 2-(3,5-dimethyl-1H-pyrazol-4-yl)acetate

HRID 2285959Notes

Reaction equation

HRID 2285959 reaction equation
[CH2:1]([O:3][C:4](=[O:13])[CH2:5][CH:6]([C:10](=O)[CH3:11])[C:7](=O)[CH3:8])[CH3:2].C(O)(=O)C.O.[NH2:19][NH2:20]>CO>[CH2:1]([O:3][C:4](=[O:13])[CH2:5][C:6]1[C:10]([CH3:11])=[N:19][NH:20][C:7]=1[CH3:8])[CH3:2]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 24654Hydrazine hydrate (1:1)HCID 87820Ethyl 3-acetyl-4-oxopentanoate

Product 1

HCID 16394806ethyl 2-(3,5-dimethyl-1H-pyrazol-4-yl)acetateYield 89%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

18.6 grams 3,3-diacetyl-propionic acid-ethyl ester, 9.0 grams glacial acetic acid and 150 milliliters methanol were mixed, and 5.3 grams hydrazine hydrate were added dropwise to this mixture within 30 minutes. The reaction mixture was then heated to the boiling temperature under reflux for 3 hours. The reaction mixture was then evaporated and distilled in vacuo. The fraction obtained at 142°-150° C./0.05 Torr consisted of an oil which later crystallized. 16.2 grams 3,5-dimethyl-1H-pyrazol-4-acetic acid-ethyl ester were obtained, representing a yield of 80%.

Workup

  1. temperatureThe reaction mixture was then heated to the boiling temperature
  2. temperatureunder reflux for 3 hours
  3. customThe reaction mixture was then evaporated
  4. distillationdistilled in vacuo
  5. customThe fraction obtained at 142°-150° C./0.05 Torr
  6. customlater crystallized

Sources & evidence

ORD record
ord-d5aa23eeca824a3fb2111702a032686c
Source dataset
uspto-grants-1982_04
Patent number
US04325962

Reaction notes

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