A versatile, alternative and environmentally benign strategy for the synthesis of a series of pyrazoles has been successfully performed in water using PEG–SO3H as an acidic catalyst. The products are obtained in high yield from the one-pot reaction procedure involving dicarbonyl compounds and hydrazines/hydrazides. This new method totally avoids the use of organic acids and toxic or expensive solvents in this reaction. The catalyst is waste-free, easily prepared, and efficiently re-used.
在
水相中使用P
EG-SO3H作为酸性催化剂,成功地实现了一种合成一系列
吡唑类化合物的多功能、替代性及环境友好型策略。通过涉及二羰基化合物与酰
肼/酰
肼化合物的单锅反应程序,产物以高收率获得。该新方法完全避免了在此反应中使用有机酸和有毒或昂贵的溶剂。催化剂无废弃物产生,易于制备,并可高效重复使用。