Ethanol → ethyl 1-tert-butyl-5-methyl-1H-pyrazole-4-carboxylate

HRID 599313Notes

Reaction equation

HRID 599313 reaction equation
Cl.[C:2]([NH:6][NH2:7])([CH3:5])([CH3:4])[CH3:3].CN([CH:11]=[C:12]([C:16](=O)[CH3:17])[C:13]([O-:15])=[O:14])C.[CH2:19](O)[CH3:20]>CCOCC>[C:2]([N:6]1[C:16]([CH3:17])=[C:12]([C:13]([O:15][CH2:19][CH3:20])=[O:14])[CH:11]=[N:7]1)([CH3:5])([CH3:4])[CH3:3]

Participants

5

Reactant 3

HCID 702EthanolHCID 81889tert-Butylhydrazine monohydrochlorideHCID 86629460(Dimethylaminomethylene)-3-oxobutanoate

Product 1

HCID 13654177ethyl 1-tert-butyl-5-methyl-1H-pyrazole-4-carboxylateYield 65%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

In ethanol (10 mL) was placed the tert-butylhydrazine hydrochloride (1.35 g, 10.8 mmol) and ethyl 2-((dimethylaminomethylene)-3-oxobutanoate (2.00 g, 10.8 mmol). The mixture warmed to reflux and stirred for 2 hrs, cooled to RT and stirred overnight. The mixture was evaporated at reduced pressure to give an oil which was dissolved in ether (25 mL) and washed successively with water (25 mL), saturated sodium bicarbonate (25 mL) and brine (25 mL), dried (Na2SO4 and evaporated at reduced pressure to give an oil. The oil was purified by chromatography (Biotage S1-25 column, 10-40% ethyl acetate/Hex 750 mL) to give ethyl 1-tert-butyl-5-methyl-1H-pyrazole-4-carboxylate (1.48 g, 65% yield) as an oil. MS (ESI) m/z: 211.0 (M+H+).

Workup

  1. temperatureThe mixture warmed
  2. temperatureto reflux
  3. stirringstirred overnight
  4. customThe mixture was evaporated at reduced pressure
  5. customto give an oil which
  6. washwashed successively with water (25 mL), saturated sodium bicarbonate (25 mL) and brine (25 mL)
  7. dry with materialdried (Na2SO4
  8. customevaporated at reduced pressure
  9. customto give an oil
  10. customThe oil was purified by chromatography (Biotage S1-25 column, 10-40% ethyl acetate/Hex 750 mL)

Sources & evidence

ORD record
ord-5676cb8321db4570b4f15d2f6209e294
Source dataset
uspto-grants-2011_03
Patent number
US07897762B2

Reaction notes

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