Ethyl 2,4-dioxovalerate → Ethyl 1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-5-carboxylate

HRID 1013030Notes

Reaction equation

HRID 1013030 reaction equation
Cl.[CH3:2][O:3][C:4]1[CH:9]=[CH:8][C:7]([NH:10][NH2:11])=[CH:6][CH:5]=1.O=[C:13]([CH2:19][C:20](=O)[CH3:21])[C:14]([O:16][CH2:17][CH3:18])=[O:15]>C(O)C.O>[CH2:17]([O:16][C:14]([C:13]1[N:10]([C:7]2[CH:8]=[CH:9][C:4]([O:3][CH3:2])=[CH:5][CH:6]=2)[N:11]=[C:20]([CH3:21])[CH:19]=1)=[O:15])[CH3:18].[CH2:17]([O:16][C:14]([C:13]1[CH:19]=[C:20]([CH3:21])[N:10]([C:7]2[CH:8]=[CH:9][C:4]([O:3][CH3:2])=[CH:5][CH:6]=2)[N:11]=1)=[O:15])[CH3:18]

Participants

6

Reactant 2

HCID 69208Ethyl 2,4-dioxovalerateHCID 27239044-Methoxyphenylhydrazine hydrochloride

Product 2

HCID 11021617Ethyl 1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-5-carboxylateHCID 228319021-(4-Methoxy-phenyl)-5-methyl-1H-pyrazole-3-carboxylic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

4-Methoxyphenylhydrazine hydrochloride (6.05 g, 34.8 mmol) and ethyl 2,4-dioxovalerate (4.45 mL, 31.6 mmol) were stirred overnight at 80° C. in ethanol (80 mL). After the solution was allowed to cool to room temperature, it was diluted with water and extracted with ethyl acetate. The organic layer was washed with water, 1 N HCl, and saturated sodium bicarbonate. Concentration and SiO2 chromatography with 20-30% ethyl acetate/hexanes gave 3.1 g of the title compound along with 2.9 g of 1-(4-methoxyphenyl)-5-methyl-1H-pyrazole-3-carboxylic acid ethyl ester.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe organic layer was washed with water, 1 N HCl, and saturated sodium bicarbonate
  3. concentrationConcentration and SiO2 chromatography with 20-30% ethyl acetate/hexanes

Sources & evidence

ORD record
ord-1e0b480340d74a3d88f15b7c20a9dc58
Source dataset
uspto-grants-2011_07
Patent number
US07981896B2

Reaction notes

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