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

Participants

Reaction Conditions

Reaction Steps

Ethyl-2,4-dioxovalerate (0.555 g, 3.5 mmol) and 4-methoxyphenylhydrazine hydrochloride (0.67 g, 3.8 mmol) were mixed in ethanol and heated to 80° C. overnight. The reaction was cooled, diluted with water and extracted with EtOAc. Organic layers were combined and washed with water, 10% HCl, sat. NaHCO3, dried over MgSO4 and concentrated under reduced pressure. The residue was purified on silica gel (20% EtOAc in hexanes to 30% EtOAc in hexanes). Two regioisomers were isolated, the title regioisomer being the more polar (yield 492 mg). LC-MS (C14H16N2O3 calculated 260) m/z 261 (M+H).

Provenance & Evidence