3,5-二溴-4-碘吡啶合成新方法

New Synthesis Methods of 3,5-dibromo-4-iodopyridine

报道了3,5-二溴-4-碘吡啶的两种新合成方法。首先以4-氨基吡啶为起始原料,经过溴代、再经过重氮化反应得到中间体3,4,5-三溴吡啶,然后以3,4,5-三溴吡啶为主要原料采用两种卤素交换反应方法得到3,5-二溴-4-碘吡啶。最后对两种卤素交换反应方法从成本、收率等方面进行了对比,对比结果表明卤交换反应中采用乙酰氯要明显优于三甲基氯硅烷。

Two new methods are proposed in the paper for the synthesis of 3,5-dibromo-4-iodopyridine. First, 3,4,5- tribromopyridine was synthesized from pyridin-4-amine by the reaction of bromination and diazotization. Then, 3,5-dibromo- 4-iodopyridine was synthesized from the main starting material of 3,4,5-tribromopyridine by the halogen exchange reaction . When the two methods were compared in eost and yield, the results showed that the halogen exchange method with acetyl chloride was better than that of chlorotrimethylsilane.