Synthesis of 3-cyano-2-fluoropyridines

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• 作者：Anatoliy M. Shestopalov ; Ludmila A. Rodinovskaya ; Alex ; er E. Fedorov ; Victor E. Kalugin ; Kirill G. Nikishin ; Alex ; r A. Shestopalov ; Andrei A. Gakh
• 关键词：Fluoropyridines ; Synthesis ; Nucleophilic substitution
• 刊名：Journal of Fluorine Chemistry
• 出版年：2009
• 出版时间：February 2009
• 年：2009
• 卷：130
• 期：2
• 页码：236-240
• 全文大小：337 K

文摘

The synthesis of 3-cyano-2-fluoropyridines from readily available precursors was achieved via nucleophilic substitution of a leaving group in the 2-postion with KF or Bu₄NF in polar aprotic solvents such as DMF and DMSO. Ionic tetrahydrothiophenium fragment is the most effective leaving group, the methanesulfonyl moiety is a somewhat less effective, and Br- and Cl- are the least effective. Relatively mild conditions of the reaction between (2-pyridyl)-tetrahydrothiophenium salts and KF, as well as the convenience of one-step synthesis of these salts from 2(1H)-pyridinethiones, make these salts the compounds of choice for the preparation of ring-fluorinated pyridines.