Ethyl propiolate → HCID 178448514, compound

HRID 415957Notes

Reaction equation

HRID 415957 reaction equation
Cl.[C:2]([NH:6][NH2:7])([CH3:5])([CH3:4])[CH3:3].[C:8](OCC)(=[O:11])[C:9]#[CH:10].CC(C)([O-])C.[K+]>C(O)(C)(C)C>[C:2]([N:6]1[CH:10]=[CH:9][C:8]([OH:11])=[N:7]1)([CH3:5])([CH3:4])[CH3:3]

Participants

5

Reactant 3

HCID 12182Ethyl propiolateHCID 81889tert-Butylhydrazine monohydrochlorideHCID 23665647Potassium tert-butoxide

Product 1

HCID 178448514HCID 178448514, compoundYield 1.1%

Reagents, catalysts & solvents 1

HCID 6386tert-ButanolSolvent

Conditions

Temperature
35 °C

Procedure

t-Butylhydrazine hydrochloride (4.5 g, 35.7 mmol) was suspended in t-butanol (35 ml) at room temperature in a dry nitrogen atmosphere. The mixture was warmed to 35° C., ethyl propiolate (3.85 g, 39.3 mmol) dropwise added and, after ice cooling, potassium t-butoxide (13.8 g, 107 mmol) was slowly added in small portions. The resulting mixture was stirred overnight at room temperature. The solvent was evaporated in vacuo, water added to the residue and extracted with dichloromethane. The aqueous phase was acidified by addition of acetic acid, evaporated to dryness in vacuo and the residue was extracted several times with ethyl acetate. The combined organic phases were dried over sodium sulphate, filtered and evaporated yielding 53 mg of 1-tert-butyl-1H-pyrazol-3-ol as a beige colour solid.

Workup

  1. customThe solvent was evaporated in vacuo, water
  2. additionadded to the residue
  3. extractionextracted with dichloromethane
  4. additionThe aqueous phase was acidified by addition of acetic acid
  5. customevaporated to dryness in vacuo
  6. extractionthe residue was extracted several times with ethyl acetate
  7. dry with materialThe combined organic phases were dried over sodium sulphate
  8. filtrationfiltered
  9. customevaporated

Sources & evidence

ORD record
ord-8459ea08eb6f4f1f91fc499812ef8ce5
Source dataset
uspto-grants-2012_01
Patent number
US08088812B2

Reaction notes

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