摘要
以苯酐为原料,水为介质,先用氢氧化钠中和生成邻苯二甲酸单钠盐,再向混合体系通氯气,亲电取代得纯度大于72%(HPLC)的4-氯邻苯二甲酸单钠盐。然后经酸化、脱水、精馏。中试规模制备了纯度大于98.5%(HPLC)的4-氯邻苯二甲酸酐。探索了反应条件对转化率和选择性的影响。结果表明,最佳反应条件为:体系的pH4.5～5.5、水/苯酐质量比2.0～2.2、反应温度55～65℃、通氯速度30～50L/min,反应时间180～220min。苯酐转化率84.4%,总收率50%～60%。
The sodium salt of phthalic anhydride is prepared by neutralization of sodium hydroxide with phthalic anhydride and an aqueous medium, subsequently the sodium salt of 4-chloro phthalic anhydride is synthesized by electrophilic substitution of chlorine gas, and the purity is more than 72% （HPLC）. Then after acidification, dehydration and rectification, 4-chloro phthalic anhydride are gained with purity more than 98.5% （HPLC） in the pilot-plant-scale. The effect of various reaction conditions on selectivity and conversion is investigated. The experimental results indicate that the production yield can reach 50% - 60% and the conversion of phthalic anhydride is 84.4% under the optimum reaction conditions： the system pH value of 4.5 - 5.5; the mass ratio of water to phthalic anhydride of 2.0 - 2.2; reaction temperature of 55 - 65 ℃ ; reaction time of 180 - 220 min.
出处
《现代化工》
CAS
CSCD
北大核心
2010年第2期81-84,86,共5页
Modern Chemical Industry
关键词
4-氯邻苯二甲酸酐
氯气
中试
4-Chlorephthalic anhydride
chlorine
scale-up synthesis
