One-pot solvent-free synthesis of 1,3,5-trisubstituted 1H-pyrazoles catalyzed by H3[PW12O40]/SiO2 under microwave irradiation
作者:Dawei Zhang、Lu Ren、Ailing Liu、Wenyu Li、Yuxin Liu、Qiang Gu
DOI:10.1007/s00706-022-02902-2
日期:2022.3
An efficient synthesis of 1,3,5-trisubstituted 1H-pyrazoles was developed. 1,3,5-Trisubstituted-1H-pyrazoles were synthesized starting from α,β-unsaturated aldehydes/ketones and hydrazine using catalyst H3[PW12O40]/SiO2 under microwave irradiation and solvent-free conditions (74–90%) and were characterized by HR-MS, FT-IR, 1H NMR, and 13C NMR spectroscopy. It was found that silica had a good loading
开发了1,3,5-三取代1 H-吡唑的有效合成方法。使用催化剂 H 3 [ PW 12 O 40 ]/SiO 2在微波辐射和无溶剂条件下(74- 90%) 并通过 HR-MS、FT-IR、1 H NMR 和13进行了表征C 核磁共振波谱。研究发现,二氧化硅对磷钨酸有良好的负载分散作用,能有效吸收微波能促进缩合反应。该方法的优点是反应条件环保、操作简单、底物广泛、收率高、H 3 [PW 12 O 40 ]/SiO 2可重复利用。此外,还给出了化合物1-(4-氯苯基)-5-(2-甲氧基苯基)-3-(4-硝基苯基)-1 H-吡唑在三斜晶系P-1空间群中的晶体结构。 图形概要