An improved Pfitzinger reaction for the direct synthesis of quinoline-4-carboxylic esters/acids mediated by TMSCl

作者：Zhou, Pan; Hu, Biao; Zhao, Siyuan; Zhang, Qiaohe; Wang, Yanqin; Li, Xiang^*; Yu, Fuchao^*

来源：Tetrahedron Letters, 2018, 59(32): 3116-3119.

DOI：10.1016/j.tetlet.2018.07.006

• Quinoline-4-carboxylic esters/acids
• Improved Pfitzinger reaction
• TMSCl-promoted
• N,N-Dimethylenaminones
• Isatins

An efficient and facile synthesis of quinoline-4-carboxylic esters/acids by TMSCl-promoted reaction of easily available N,N-dimethylenaminones and isatins in alcohols/water has been developed. The improved Pfitzinger reaction involves esterification and cyclization in one-step process, and in situ formed a carboxylic esterlacid group (CO2R or COOH) at the 4-position of quinoline ring. Moreover, the key features of this protocol are readily available starting materials, good functional group tolerance, mild reaction conditions, operational simplicity, and feasibility of scale up.

• 出版日期2018-8-8
• 单位昆明理工大学