- 专利标题: Method and production line for preparing 2,6-dichloropyridine through gas phase photochlorination of pyridine
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申请号: US16221601申请日: 2018-12-17
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公开(公告)号: US10442766B1公开(公告)日: 2019-10-15
- 发明人: Huiyue Li , Keqiang Jin , Jiaquan Zhu
- 申请人: Zhejiang Avilive Chemical Co., Ltd.
- 申请人地址: CN Zhejiang
- 专利权人: Zhejiang Avilive Chemical Co., Ltd.
- 当前专利权人: Zhejiang Avilive Chemical Co., Ltd.
- 当前专利权人地址: CN Zhejiang
- 代理商 Tony Hom, Esq.
- 优先权: CN201811272344 20181030
- 主分类号: C07D213/61
- 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.