4H-Pyrano[3,2-c]coumarinderivatives are an important class of pharmaceutical compounds that are expensive to prepare by previously reported methods. An efficient and green method was developed to obtain these derivatives using the deep eutectic solvent (DES) zinc chloride/acetamide (n:n = 1:4), which acted as both the catalyst and the solvent for the reaction. An aromatic aldehyde, 4-hydroxycoumarin
New amine modified nanozeolites were prepared and characterized using FT-IR, TGA, DTG, SEM, and TEM. Then the synthesized nanozeolites were employed as novel, recyclable and safe catalysts for the one-pot, three-component condensation of 4-hydroxycoumarin with aldehydes and malononitrile to produce new and known pyrano[2,3-c]chromenes as potent biologically active compounds. This novel method has many advantages, such as high product yield and a simple work-up procedure.
catalyst, simple product separation from the reaction mixture and generality of the method, easy handling, low catalyst cost, and mild reaction conditions make this approach an eco-friendly procedure for synthesizing the chromenes. The obtained results demonstrated that the presented catalytic procedure could be effective in the synthesis of other useful products under green reaction conditions. Graphical
本研究通过用3-氯丙基三甲氧基硅烷(CPTMS)对纳米NaY沸石(YZ)进行后改性,然后合成纳米NaY沸石负载二甲双胍(YZ/PS/Met)作为一种环保且可重复使用的纳米催化剂。与二甲双胍(Met)反应。采用傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)、动态光散射(DLS)、热重分析等多种技术对二甲双胍功能化纳米NaY沸石(YZ/PS/Met)进行了表征(TGA)、场发射扫描电子显微镜 (FESEM)、能量色散 X 射线光谱 (EDS)、Brauer-emmett-teller (BET)、t 图和元素分析。然后,选择2-氨基-4H-色烯的合成来研究(YZ/PS/Met)的催化活性,该方法在室温下提供了良好的产率(81-98%)、反应时间短、和绿色溶剂(EtOH)。该催化剂可以轻松地从反应介质中去除,并可连续重复使用七次,而不会显着降低催化剂性能。 NaY 表面附着的二甲双胍 (Met)