Ethyl 2-formyl-3-oxopropanoate → 1-(5-carboxy-2-methyl-phenyl)-1H-pyrazole-4-carboxylic acid ethyl ester

HRID 1723954Notes

Reaction equation

HRID 1723954 reaction equation
[CH2:1]([O:3][C:4](=[O:10])[CH:5]([CH:8]=O)[CH:6]=O)[CH3:2].Cl.[NH:12]([C:14]1[CH:15]=[C:16]([CH:20]=[CH:21][C:22]=1[CH3:23])[C:17]([OH:19])=[O:18])[NH2:13]>CCO>[CH2:1]([O:3][C:4]([C:5]1[CH:8]=[N:13][N:12]([C:14]2[CH:15]=[C:16]([C:17]([OH:19])=[O:18])[CH:20]=[CH:21][C:22]=2[CH3:23])[CH:6]=1)=[O:10])[CH3:2]

Participants

4

Reactant 2

HCID 11029955Ethyl 2-formyl-3-oxopropanoateHCID 567775083-Hydrazino-4-methylbenzoic acid hydrochloride

Product 1

HCID 575597081-(5-carboxy-2-methyl-phenyl)-1H-pyrazole-4-carboxylic acid ethyl esterYield 68%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A solution of 2-formyl-3-oxo-propionic acid ethyl ester (Bertz, S. H.; Dabbagh, G.; Cotte, P. J. Org. Chem. 1982, 47, 2216) (1.44 g, 10 mmol) in EtOH (10 mL) was cooled in an ice bath. A slurry of 3-hydrazino-4-methyl-benzoic acid hydrochloride (2.02 g, 10 mmol) in EtOH (50 mL) was added and the reaction stirred overnight. The EtOH was removed under reduced pressure and the residue partitioned between water and CH2Cl2. The layers were separated and the organic layer washed with brine. The organic layer was dried over Na2SO4, filtered, and concentrated. Hexanes were added and the solution concentrated. The resulting solid was collected by vacuum filtration, washed with hexanes and dried under vacuum to provide 1-(5-carboxy-2-methyl-phenyl)-1H-pyrazole-4-carboxylic acid ethyl ester (1.86 g, 68%) as a yellow solid: ESI MS m/z 275 [C14H14N2O4+H]+.

Workup

  1. customThe EtOH was removed under reduced pressure
  2. customthe residue partitioned between water and CH2Cl2
  3. customThe layers were separated
  4. washthe organic layer washed with brine
  5. dry with materialThe organic layer was dried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. additionHexanes were added
  9. concentrationthe solution concentrated
  10. filtrationThe resulting solid was collected by vacuum filtration
  11. washwashed with hexanes
  12. customdried under vacuum

Sources & evidence

ORD record
ord-b0d89e4a73eb4859ae8d022fbe3fa840
Source dataset
uspto-grants-2009_02
Patent number
US07485657B2

Reaction notes

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