1-Isopropylhydrazine → Ethyl 1-isopropyl-5-methyl-1H-pyrazole-3-carboxylate

HRID 706547

Reaction equation

HRID 706547 reaction equation
O=[C:2]([CH2:8][C:9](=O)[CH3:10])[C:3]([O:5][CH2:6][CH3:7])=[O:4].[CH:12]([NH:15][NH2:16])([CH3:14])[CH3:13]>C(O)(=O)C>[CH:12]([N:15]1[C:9]([CH3:10])=[CH:8][C:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])=[N:16]1)([CH3:14])[CH3:13]

Participants

4

Reactant 2

HCID 527891-IsopropylhydrazineHCID 69208Ethyl 2,4-dioxovalerate

Product 1

HCID 23005696Ethyl 1-isopropyl-5-methyl-1H-pyrazole-3-carboxylateYield 31.3%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To ethyl 2,4-dioxopentanoate (20.1 g, 127 mmol) in acetic acid (100 mL) at 0° C. was added isopropylhydrazine (9.42 g, 127 mmol) dropwise. The cold bath was removed and the reaction mixture was stirred for 2 hours. The reaction mixture was diluted with EtOAc/H2O (300 mL/100 mL). The organic layer was washed with saturated NaHCO3 aqueous solution (100 mL), H2O (50 mL) and brine (50 mL). The organic layer was dried (Na2SO4) and concentrated. The residue was purified by silica gel flash chromatography (1:2 EtOAc/hexane) to give 7.8 g (31%) of the title compound.

Workup

  1. customThe cold bath was removed
  2. additionThe reaction mixture was diluted with EtOAc/H2O (300 mL/100 mL)
  3. washThe organic layer was washed with saturated NaHCO3 aqueous solution (100 mL), H2O (50 mL) and brine (50 mL)
  4. dry with materialThe organic layer was dried (Na2SO4)
  5. concentrationconcentrated
  6. customThe residue was purified by silica gel flash chromatography (1:2 EtOAc/hexane)

Sources & evidence

ORD record
ord-bbc5acba484b4b1393eed74099398bb8
Source dataset
uspto-grants-2015_11
Patent number
US09174981B2

Linked notes

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