HCID 16638017, compound → 1-(4-Nitrophenyl)-3-oxo-2,3-dihydro-1H-pyrazole-4-carboxylic acid

Participants

Reaction Steps

The ester prepared as in (a) above (300 mg, 1.08 mmol) in 0.5N sodium hydroxide (20 ml) was stirred under nitrogen at reflux for 1 hour. The reaction mixture was allowed to cool, washed with ethyl acetate and then acidified to pH 1.5. The aqueous solution was then extracted with ethyl acetate which on drying (MgSO4) and evaporation followed by ether trituration produced the title compound (267 mg). νmax (Nujol) 1680, 1615, 1499, 1580 cm-1, δ(CD3OD+D6DMSO) 8.30 (4H, ABq, J10 Hz, aryl protons), 8.86(1H, s, C3 pyrazole proton). Found: M+, 249.0386; C10H7N3O5 requires M, 249.0386.

Provenance & Evidence