反应详情

温度

80 °C

A portion of the 5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (2.7 g, 18 mmol) is dissolved in EtOH (15 mL) and treated with aqueous sodium hydroxide solution (2.0 N solution, 20 mL, 40 mmol). The reaction is heated at 80° C. for 4 hours. The resultant mixture is then cooled and concentrated in vacuo to remove most of the EtOH. The crude is then acidified with 6N HCl until a precipitate is formed and filtered to afford 5-methyl-1H-pyrazole-4-carboxylic acid as a colorless solid (1.7 g, 74%).

1. concentrationconcentrated in vacuo
2. customto remove most of the EtOH
3. customis formed
4. filtrationfiltered