5,6,7,8-四氢咪唑并[1,2-a]吡啶-3-硼酸盐酸盐的合成

Synthesis of 5,6,7,8-Tetrahydroimidazo[1,2-a]pyridin-3-yl Boronic Acid Hydrochloride

以5-氯戊腈为原料,先经2,2-二甲氧基乙胺取代,甲酸环化成咪唑环、碘化钠关环,合成5,6,7,8,-四氢咪唑并[1,2-a]吡啶,再与硼酸三异丙酯,在正丁基锂作用下进行硼酸化,制得鲜见文献报道的目标化合物5,6,7,8-四氢咪唑并[1,2-a]吡啶-3-硼酸盐酸盐,5步反应总收率31.85%。产品经MS和1H NMR确证。该合成工艺具有反应条件温和、操作简单的优点。

5,6,7,8-Tetrahydroimidazo[1,2-a]pyridin-3-yl boronic acid hydrochloride, the titled compound, which has been rarely reported in literatures, was prepared from the intermediate compound 5,6,7,8-tetrahydroimidazo[1,2-a] pyridin with n-butyllithium and tripropylborate. The intermediate was prepared from 5-chloropentanenitrile via substitution with 2,2-dimethoxyethanamine, cyclization with formic acid, and cyclization with sodium iodide.The target compound was achieved in overall yield of 31.85% and confirmed with MS and1 H NMR. This route has the advantages of mild reaction conditions and simple procedures.