对溴甲基苯腈的合成及精制工艺研究

Technical research on synthesis and refinement of 4-bromomethyl-benzonitrile

以对甲苯腈和溴素为原料经光照溴化制得对溴甲基苯腈，产品经溶剂洗涤、混合溶剂重结晶等过程进行精制。通过对反应的考察，得到最佳合成工艺条件为n（对甲苯腈）：n（溴素）=1：1．1，反应温度145—150℃。产品精制选择乙醇为洗涤溶剂，乙醇与乙酸乙酯组成的混合溶剂作为重结晶溶剂，其中y（乙醇）：y（乙酸乙酯）=3：1，采用IR和MS对产品进行定性分析，经GC分析，产品纯度达99％以上，总收率为68．6％。

4-Bromomethyl-benzonitrile was prepared with p-methyl-benzonitrile and bromine by photochemical bromination. The crude product was washed and recrystallized by solvent and mixed solvent. The reaction conditions were explored and the optimal conditions were as follows, n（4-methyl-benzonitrile） ： n（bromine） = 1 ： 1.1, reaction temperature was 145 - 150 ℃. Ethanol and mixed solvent consisting of ethanol and ethyl acetate were selected as washing and recrystallizing solvent respectively. IR and MS were employed for qualitative analysis. The product was analyzed by GC and the purity was above 99%. The total yield was 68.6%.