4,4'-二羟基二苯砜合成新工艺的研究

对苯酚磺化、脱水法合成4,4'-二羟基二苯砜（BPS）工艺进行改进。研究了使用新的催化剂（2,6-萘二磺酸）和溶剂（均三甲苯-均四甲苯混合溶剂），提高经苯酚和浓硫酸合成BPS的收率和纯度。详细研究了合成过程中所用溶剂类型及混合溶剂比例、催化剂种类及用量对BPS收率、纯度及异构体2,4'-二羟基二苯砜变化规律的影响。较好的工艺条件为：100 g均三甲苯-均四甲苯混合溶剂（二者质量比3∶1），5 g 2,6-萘二磺酸催化剂，98.5 g苯酚，在110 ℃将51.2 g硫酸滴加完成后，将反应液快速升温至回流温度172 ℃并保持5 h。BPS产品收率可达99.3%，纯度为96.49%。该方法收率高，催化剂便宜，易于工业化。

A new process for preparation of 4,4'-dihydroxydiphenylsulfone

A new process for synthesis of 4,4'-dihydroxydiphenylsulfone (BPS) by the sulfonation of phenol with concentration sulfuric acid followed by dehydration was developed. A new catalyst (naphthalene-2,6-disulfonic acid) and solvent system (mixed solvent of mesitylene-durene) were adopted to improve the yield and purity of BPS. The effects of type of solvent，weight ratio of mixed solvent，type and amount of catalyst on BPS yield，purity and isomer (2,4'-dihydroxydiphenylsulfone) ratio were investigated. The new process was as follow：To the reaction mixture of 100g mixed solvent of mesitylene-durene (the weight ratio 3∶1)，5 g catalyst of naphthalene-2,6-disulfonic acid and 98.5 g phenol 51.2 g sulfuric acid was added dropwisely at 110 ℃. Then the reaction system was heated rapidly to the reflux temperature of 172 ℃ and maintained for 5h. The yield of product BPS reached 99.3% and the purity was 96.49%. The product yield of the process was high and the catalyst was relatively cheap，and the new process was easy to be commercialized.