【摘要】 以高沸程石油醚代替1,1,2,2-四氯乙烷为溶剂,对焦性没食子酸合成2,3,4,4’-四羟基二苯甲酮的经典方法——三氟化硼催化法进行改进。在常温下快速搅拌和加热,使原料和溶剂体系由混悬液转变成棕色油状溶液,一定时间后瞬间产生大量黄色油性结晶产物沉淀,完成合成反应。采用正交试验法优化反应条件为:焦性没食子酸0.05 mol、对羟基苯甲酸用量0.055 mol、催化剂用量0.16 mol(20 mL)、反应温度110℃、反应时间1 h,在此条件下,2,3,4,4’-四羟基二苯甲酮产率达83.24%,产品纯度为97.83%。该方法与传统方法的产率相近,生产过程中比1,1,2,2-四氯乙烷的毒性小、成本低,改进的合成反应还具有时间短、后处理简便、催化剂可回收等优点。对提纯到99.53%的产物,通过红外吸收光谱、核磁共振谱、质谱等方法进行鉴定和表征,确定了产物为2,3,4,4’-四羟基二苯甲酮。更多还原

【Abstract】 A new synthesis of 2,3,4,4’-tetrahydroxybenzophenone by boron trifluoride etherate catalysis was proposed in this paper. In the new method,high boiling-point petroleum ether was used as the reaction solvent to replace the poisonous and expensive 1,1,2,2-tetrachloroethane. Although p-hydroxybenzoic acid,pyrogallic acid,boron trifluoride and petroleum ether were immiscible at room temperature,the reaction system could be gradually turned into brown oily solution in the heating and rapid mixing conditions. After a period of time,a large amount of yellow crystalline products were precipitated. According to the results of orthogonal experiments,the optimum reaction conditions were as follows: pyrogallic acid 0. 05 mol,p-hydroxybenzoic acid 0. 055 mol,catalyst 0. 16 mol( 20 mL),reaction temperature 110 ℃ and reaction time 1 h. Under this condition,the yield reached 83. 24% and product purity 97. 83 %. The new method possessed many advantages,e. g.,low toxicity,low cost,short reaction time,easy operation and the recycled catalyst. The product with 99. 53% purity by recrystallization in water was identified as 2,3,4,4’-tetrahydroxybenzophenone by the combination of IR,NMR and EI-MS techniques.更多还原