反应详情

A mixture of ethyl 1-benzyl-1H-pyrazole-4-carboxylate (53.0 g, 0.23 mol) and LiOH (19.4 g, 0.46 mol) in THF (100 mL) and H2O (100 mL) was stirred at refluxed for 6 h. Then, THF was removed, the residue was acidify by 6 N HCl, precipitation was formed, filtered and dried to give the desired compound as a white solid (44.0 g, 92.8%). 1H NMR (DMSO-d6) δ 12.36 (s, 1H), 8.39 (s, 1H), 7.85 (s, 1H), 7.38-7.27 (m, 5H), 5.37 (s, 2H). MS (ESI) m/e [M+1]+ 202.9.

1. temperatureat refluxed for 6 h
2. customThen, THF was removed
3. customprecipitation
4. customwas formed
5. filtrationfiltered
6. customdried