溴化钾-浓硫酸法合成苄基溴

Synthesis of benzyl bromide using potassium bromide and concentrated sulfuric acid method

溴化钾作为工业生产2-羟基-4-正辛氧基二苯甲酮的副产品,在浓硫酸存在的条件下,与苯甲醇进行反应合成苄基溴。考察了反应条件,确定较佳工艺为:溴化钾0.1 mol,苯甲醇0.08 mol,浓硫酸5 mL,水2.5 mL,回流反应4 h分离,收率高达94%。粗产品经气相色谱分析证明纯度较高,产品经IR和折光率进行了表征。

Benzyl bromide was synthesized from potassium bromide, a by-product from synthesis of 2-hydroxy-4-n-octyloxybenzophenone （ UV-531 ） , and benzoic alcohol in the presence of concentrated sulfuric acid. The optimal condition was obtained as follows： n （potassium bromide） = 0.1 mol, n （benzoic alcohol） =0.08 mol, V（ concentrated sulfuric acid） =5 mL, V（H20） =2.5 mL, reflux for 4 h. Yield of up to 94%. was obtained. Raw product was analyzed by GC and almost no by-product was detected. The pure product was characterized by IR and index of refraction.