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公开(公告)号：US10442766B1
公开(公告)日：2019-10-15
申请号：US16221601
申请日：2018-12-17
发明人： Huiyue Li , Keqiang Jin , Jiaquan Zhu
IPC分类号： C07D213/61 , C07B39/00 , B01D3/14 , B01J19/12
摘要： The present invention relates to a method for preparing 2,6-dichloropyridine with product purity greater than or equal to 99.0% through gas phase photochlorination of pyridine by using trifluoromethyl chlorobenzene as a solvent for reaction between pyridine and chlorine gas. Gasified pyridine and heated chlorine gas are enabled to continuously experience chlorination reaction under irradiation of ultraviolet light by using gasified pyridine and heated chlorine gas as starting materials and using heated trifluoromethyl chlorobenzene as a solvent, and a gas phase reaction product and the solvent are cooled to obtain pyridine chlorination solution. Advantages: firstly, it pioneers the precedent of direct and high-selectivity preparation of 2,6-dichloropyridine through gas phase photochlorination, and not only can the 2,6-dichloropyridine product with purity greater than or equal to 99.0% be obtained, but also industrial production is facilitated; and secondly, the selectivity of pyridine chlorination is high, the chlorination solution is subjected to crude distillation to separate high-boiling-point substances, the crude distillate is subjected to cooling crystallization or rectification to separate the solvent, the solvent is reused, and not only can the 2,6-dichloropyridine product with purity greater than or equal to 99.0% be obtained, but also the purposes of no pollution, low energy consumption and low cost can be realized.
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2.发明授权公开(公告)号：US10851060B2
公开(公告)日：2020-12-01
申请号：US16221600
申请日：2018-12-17
发明人： Huiyue Li , Keqiang Jin , Jiaquan Zhu
IPC分类号： C07D213/04 , C07D213/61 , B01D3/14 , B01J19/12 , C07B39/00
摘要： The present invention relates to a method for preparing 2,6-dichloropyridine with product purity greater than or equal to 99.0% by using trifluoromethyl chlorobenzene as a solvent for reaction between pyridine and chlorine gas. The preparation process comprises the following steps: enabling pyridine and chlorine gas to continuously experience chlorination reaction under irradiation of ultraviolet light by using pyridine and chlorine gas as starting materials and using trifluoromethyl chlorobenzene as a solvent, and cooling a chlorination reaction product and the solvent to obtain pyridine chlorination solution. Advantages: firstly, it pioneers the precedent of direct and high-selectivity preparation of 2,6-dichloropyridine through liquid phase photochlorination, and not only can the 2,6-dichloropyridine product with purity greater than or equal to 99.0% be obtained, but also industrial production is facilitated; and secondly, not only can the reuse of the separated solvent in the preparation process of the 2,6-dichloropyridine product with purity greater than or equal to 99.0% be realized, but also the purposes of low pollution, low energy consumption and low cost in the preparation process can be realized.
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公开(公告)号：US10577326B1
公开(公告)日：2020-03-03
申请号：US16221603
申请日：2018-12-17
发明人： Huiyue Li , Keqiang Jin , Jiaquan Zhu
IPC分类号： C07D213/61 , C07B39/00 , B01D3/14 , B01J19/12
摘要： The present invention relates to a method for preparing 2-chloro-6-trichloromethylpyridine with product purity greater than or equal to 99.0% by using trifluoromethyl chlorobenzene as a solvent for reaction between 2-methylpyridine with chlorine gas, in which 2-methylpyridine and chlorine gas are used as starting materials, trifluoromethyl chlorobenzene is used as a solvent, 2-methylpyridine is prepared into a liquid raw material by using the solvent trifluoromethyl chlorobenzene, and the liquid raw material is continuously fed to perform liquid phase photochlorination reaction at temperature of 160-240° C. under irradiation of ultraviolet light to obtain 2-chloro-6-trichloromethylpyridine solution. Advantages: the selectivity of reaction for the production of 2-chloro-6-trichloromethylpyridine is improved, the content of components such as isomers and pentachloromethylpyridine in the crude product is decreased significantly, the crude product is easy to be purified to obtain the 2-chloro-6-trichloromethylpyridine product with purity greater than or equal to 99.0%, and the industrial production is facilitated; and secondly, not only can the reuse of the separated solvent in the preparation process of the 2,6-dichloropyridine product with purity greater than or equal to 99.0% be realized, but also the purposes of low pollution, low energy consumption and low cost in the preparation process are realized.
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