A simple and selective green methodology has been successfully developed for Knoevenagel condensation in polyethylene glycol-400 using 10 mol % ammonium chloride as catalyst. The method is applicable to a wide range of aromatic, heteroaromatic and α,β-unsaturated aldehydes. The reactions have been found to be clean and free from the formation of the Michael adduct.

中文翻译：

---

氯化铵在作为环保溶剂的 PEG-400 中催化 Knoevenagel 缩合

使用 10 mol% 氯化铵作为催化剂，成功开发了一种简单且选择性的绿色方法，用于在聚乙二醇-400 中进行 Knoevenagel 缩合。该方法适用于范围广泛的芳香族、杂芳香族和α,β-不饱和醛。已经发现反应是干净的并且没有迈克尔加合物的形成。