4-溴-9-芴酮合成工艺研究

The Synthesis research of 4-bromo-9H-fluoren-9-one

4-溴-9-芴酮是一种重要的光电材料中间体要,目前合成方法均存在一些缺陷,难以规模化生产。本文以2,2′-二溴联苯,正丁基锂、碳酸二甲酯为原料,经过锂卤交换反应、亲核取代反应以及分子内环化反应得到目标化合物。通过对反应所需的溶剂、温度、时间和物料比等条件进行筛选,确定最佳反应条件为:以四氢呋喃为溶剂,锂卤交换反应温度为-90^-95℃,亲核取代反应温度为-85^-95℃,物料比为n(2,2′-二溴联苯)∶n(DMC)=1∶1.5,环化试剂为甲磺酸,环化反应温度为120℃。本文采用的合成方法简单,产物收率及纯度高,总收率达68.3%,HPLC纯度达到99.5%以上,适合工业化生产。产物结构经1H NMR、13C NMR和GC-MS确证。

4-Bromo-9H-fluoren-9-one is an important intermediate in fine chemicals.The current synthesis methods all have some defects and it is difficult to apply in scale manufacturing.In this paper,4-bromo-9H-fluoren-9-one was synthesized by lithium-halogen exchange reaction,nucleophilic substitution reaction and intramolecular ring-closure reaction,using 2,2′-dibromobiphenyl,n-butyllithium and dimethyl carbonate as raw material.Through the screening of solvent,temperature,time and material ratio for the reaction,the optimum reaction conditions were as follows:tetrahydrofuran as solvent,lithium halogen exchange reaction temperature for-90^-95℃,nucleophilic substitution reaction temperature for-85^-95℃,material ratio of n(2,2′-bromine biphenyl)∶n(DMC)=1∶1.5,mesylate as cyclization reagent,cyclization reaction temperature for 120℃.The synthesis method was simple,and the yield and purity of product were high.The yield of three steps was 68.3%,and the purity was over 99.5%detected by HPLC.The structure was confirmed by 1H NMR、13C NMR and GC-MS.