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

HRID 706729

Reaction equation

HRID 706729 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%

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 drop-wise isopropylhydrazine (9.42 g, 127 mmol). The cold bath was removed and the reaction mixture was stirred for 2 hours. The reaction mixture was then 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 the desired product (31%).

Workup

  1. customThe cold bath was removed
  2. additionThe reaction mixture was then 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-cf4d2d83059d4e55b7bb41ef16a292d7
Source dataset
uspto-grants-2015_11
Patent number
US09174981B2

Linked notes

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