2-羟基-4-甲氧基二苯甲酮的合成及工业放大试验

以2,4-二羟基二苯甲酮和硫酸二甲酯为原料,合成了2-羟基-4-甲氧基二苯甲酮(UV-9)。考察了溶剂、碱、物料摩尔比和反应时间、催化剂对反应的影响。溶剂的极性太强或太弱对反应都不利,中等极性的丙酮为合适的反应溶剂,相转移催化剂对反应没有促进作用。实验结果表明:丙酮40 mL,无水碳酸钾0.12 mol,n(2,4-二羟基二苯甲酮)/n(硫酸二甲酯)=1(各0.2 mol),回流反应4.0 h,反应结束后蒸出丙酮回收再利用,余液水洗掉CH3SO4K后,油相经乙醇重结晶得到UV-9,其分离产率达87%。工业合成试验在3 m3反应釜中进行,丙酮910 kg,碳酸钾322 kg,2,4-二羟基二苯甲酮830 kg,硫酸二甲酯489 kg,在上述反应条件下,UV-9的产率达89%,回收丙酮经重复使用10次后,产率仍可达到88%。

Laboratory and Industrial Synthesis of 2-Hydroxy-4-methoxybenzophenone

2-Hydroxy-4-methoxybenzophenone(UV-9) was synthesized from 2,4-dihydroxybenzo-phenone and dimethyl sulfate.The polarity of solvent has great influence on the reaction.Solvents of too high or too low polarity can′t be used.Acetone is suitable for this reaction because of its moderate polarity.Phase transfer catalyst has no effect on the reaction.Thus,reflux 0.2 mole 2,4-dihydroxybenzophenone and 0.2 mole dimethyl sulfate in 40 mL acetone with 0.12 mole potassium carbonate for 4.0 h,remove the acetone after the reaction,wash the crude product with hot water,and recrystallize the product in ethanol.The isolated yield of UV-9 was up to 87%.Industrial synthesis was carried out in 3 m~3 reactor with feedstock of 910 kg acetone,322 kg K_2CO_3,830 kg 2,4-dihydroxybenzophenone and 489 kg dimethyl sulfate by the same procedure and the yield of UV-9 reached 89%.The recovered acetone was reused ten times and the yield of UV-9 can still attain 88%.