Recyclable task-specific acidic ionic liquid [NMP]H2PO4: Microwave-assisted, efficient one-pot, two-step tandem synthesis of fused thiazolo[2,3-b]quinazolinone and thiazolo[2,3-b]quinazoline derivatives
作者:Gondru Ramesh、Rajitha Gali、Ravibabu Velpula、Bavantula Rajitha
DOI:10.1007/s11164-015-2249-1
日期:2016.4
A novel, time-effective, eco-conscious and microwave-assisted tandem one-pot, two-step reaction has been described for the synthesis of thiazolo[2,3-b]quinazolinone (4a–f) and thiazolo[2,3-b]quinazoline (5a–t) derivatives in quantitative yield in the presence of inexpensive, acidic task-specific ionic liquid [NMP]H2PO4. All the synthesized compounds were well established by comparison with their literature values (1H NMR, melting points, mass spectrometry and elemental analysis). The remarkable advantages of this methodology over existing conventional heating, such as increasing yields, decreasing reaction times, formation of products in an analytically pure form, operational simplicity, less energy consumption, cost-effectiveness, recyclability and reusability of the catalyst, make this protocol "green" and environmentally benign.
在廉价的酸性特异性离子液体 [NMP]H2PO4 的存在下,描述了一种新颖、省时、环保和微波辅助的串联一锅两步反应,用于定量合成噻唑并[2,3-b]喹唑啉酮(4a-f)和噻唑并[2,3-b]喹唑啉(5a-t)衍生物。通过与文献值(1H NMR、熔点、质谱和元素分析)的比较,所有合成的化合物都得到了很好的证实。与现有的传统加热方法相比,该方法具有显著的优势,如产量增加、反应时间缩短、生成的产品分析纯度高、操作简单、能耗低、成本效益高、催化剂可回收和重复使用,因此该方法是 "绿色 "和环保的。