反应详情

To a solution of the above phenyl hydrazine intermediate, (50 mg, 0.247 mmol) in trifluoroacetic acid (TFA) (500 μL) was added sodium 2-cyano-1-ethoxycarbonyl-ethenol (49 mg, 0.298 mmol). The red mixture was heated to reflux for 2 h then cooled and concentrated. Purification by silica-gel chromatography (2% NH4OH/25% MeOH in EtOAc) provided 5-amino-1-(5-carboxy-2-methyl-phenyl)-1H-pyrazole-3-carboxylic acid ethyl ester (60 mg, 83%) as a white solid: ESI MS m/z 290 [C14H15N3O4+H]+.

1. temperatureThe red mixture was heated
2. temperatureto reflux for 2 h
3. temperaturethen cooled
4. concentrationconcentrated
5. customPurification by silica-gel chromatography (2% NH4OH/25% MeOH in EtOAc)