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

HRID 2070961Notes

Reaction equation

HRID 2070961 reaction equation
CCN(/[CH:6]=[C:7](/[C:11]([O:13][CH2:14][CH3:15])=[O:12])\[C:8]([CH3:10])=O)CC.Cl.[C:17]([NH:21][NH2:22])([CH3:20])([CH3:19])[CH3:18]>CCO>[C:17]([N:21]1[C:8]([CH3:10])=[C:7]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:6]=[N:22]1)([CH3:20])([CH3:19])[CH3:18]

Participants

4

Reactant 2

HCID 81889tert-Butylhydrazine monohydrochlorideHCID 11424414HCID 11424414, compound

Product 1

HCID 13654177ethyl 1-tert-butyl-5-methyl-1H-pyrazole-4-carboxylateYield 96%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A stirred solution of diethylaminomethylene ethyl acetoacetate (552 mg, 2.8 mmol, see R. A. Fecik, P. Devasthale, S. Pillai, A. Keschavarz-Shokri, L. Sehn, and L. A. Mitscher; J. Med. Chem. 2005, 48, 1229) and tert-butyl hydrazine hydrochloride (387 mg, 3.1 mmol) in EtOH (5 mL) was heated to reflux for 15 h. The reaction mixture was cooled to room temperature and concentrated under reduced pressure. The residue was dissolved in EtOAc and saturated aqueous NaHCO3. The layers were separated and the aqueous layer was extracted with EtOAc (2×10 mL). The combined organic layer was washed with brine, dried with Na2SO4 and concentrated under reduced pressure to provide ethyl 1-tert-butyl-5-methyl-1H-pyrazole-4-carboxylate (560 mg, 96%) as a yellow oil.

Workup

  1. temperatureto reflux for 15 h
  2. concentrationconcentrated under reduced pressure
  3. dissolutionThe residue was dissolved in EtOAc
  4. customThe layers were separated
  5. extractionthe aqueous layer was extracted with EtOAc (2×10 mL)
  6. washThe combined organic layer was washed with brine
  7. dry with materialdried with Na2SO4
  8. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-cfc82c1dedc84059883bbebc7f3bdb75
Source dataset
uspto-grants-2012_10
Patent number
US08299267B2

Reaction notes

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