文档介绍：湘潭大学
硕士学位论文
2,3,5-三氯吡啶合成工艺研究
姓名:余毅
申请学位级别:硕士
专业:化学工程
指导教师:艾秋红
20070501
摘要
2,3,5-三氯吡啶是合成 3,5-二氯-2-氧基醚吡啶与噁草醚等杀虫剂与除草剂的重
要农药中间体。
本文通过对合成工艺的对比,确定了锌粉还原五氯吡啶合成2,3,5-三氯吡啶的
工艺路线,该法具有原料易得,反应路线较短等优点。通过正交实验,确定了锌
粉还原的优化反应条件为:反应温度75℃;反应时间5h;氢氧化钠浓度8mol/L;
原料配比n(锌粉):n(五氯吡啶)=3。在此条件下,2,3,5-三氯吡啶合成收率66%,比
文献收率提高3%左右。
从反应机理出发,建立了锌粉还原五氯吡啶合成2,3,5-三氯吡啶的宏观动力学
模型。采用Matlab程序编程,利用单纯形法对模型参数进行了估值。在实验范围
内,模型计算值与实验值吻合较好,通过模型检验表明该动力学模型是可靠的。
由反应活化能可知,降低反应温度有利于提高2,3,5-三氯吡啶的合成收率,为工业
反应器的放大与进一步优化提供了理论指导。
通过添加相转移催化剂,能明显加快反应速率。探讨了相转移催化锌粉还原
五氯吡啶合成 2,3,5-三氯吡啶的反应机理。确定了相转移催化锌粉还原的优化工艺
条件:反应温度 50℃、反应时间 6 小时、NaOH 溶液浓度 8mol/L、n(锌粉):n(五
氯吡啶):n(四甲基溴化铵)=3~:1:。在此条件下,收率可达 73%以上。
新工艺具有反应时间短,锌粉用量少,产品收率高等特点。2,3,5-三氯吡啶合成收
率比文献报道的收率提高了 10%左右。

关键词:2,3,5-三氯吡啶;五氯吡啶;相转移催化剂;数学模型;宏观动力学;
正交实验;单纯形法
I
ABSTRACT
2,3,5-trichloropyridine is an important intermediate for the production of
herbicidal or pesticidal active substance such as 3,5-dichloro-2-pyridinol and
isoxapyrifop.
paring different methods of preparation,we found that the way
of the preparation which used pentachloropyridine and zinc as initial reactant to
be more suitable at such way, the material could be gained easily and t-
he process was short .By orthogonal experiment,it was confirmed that the opti-
mum reaction condition:The reaction temperature was 75ºC; The reaction time was
5 hours;the concentration of sodium hydroxy was 8 mol/L;the mole ratio of
zinc to pentachloropyridine was to the conditions,the yield of 2,3,5-
trichloropyridine was about 66%,which was higher about 3% than the previous
literature.
From the reaction mechanism,this paper established ics of synth-
esis of 2,3,5-trichloropyridine by pentachloropyridine and parameter of
the reaction ics model was estimated with the Matlab program and simple
model result agreed well with experimental model was re-
liable inexperimental scope, which could reflect the truth of experim