Method for preparing 2,2'-dipyridine under palladium/carbon catalysis

Abstract

The invention discloses a method for preparing 2,2'-dipyridine under palladium / carbon catalysis, which belongs to the technical field of organic synthesis. A reaction system in the preparation method comprises the following components by mass: 20 to 30% of 2-chloropyridine, 15 to 20% of alkali, 40 to 45% of a solvent, 10 to 15% of a dispersing agent and 1.5 to 3% of a catalyst, wherein the catalyst is a palladium / carbon catalyst containing 5% by mass of palladium. According to the invention, through filtering, distillation, desalination and other treatment of reaction mother liquor, recovery and cyclic usage of mother liquor water are realized, so the water resource is saved and environmental pollution caused by sewage discharge is effectively avoided; application conditions of the palladium / carbon catalyst are mild, which is favorable for prolonging the service life of equipment; and the catalyst is convenient to regenerate, activate and recover, so production efficiency is improved and production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a palladium / carbon catalyzed preparation method of 2,2'-bipyridine. Background technique [0002] 2,2'-Bipyridyl is an important intermediate in organic synthesis, and its application scope involves many fields such as medicine, pesticide, luminescent material, indicator and so on. At present, my country's 2,2'-bipyridine production capacity is insufficient, and about 20% of it needs to be imported every year. Especially with the rapid development of the pesticide industry, the demand for 2,2'-bipyridine is also increasing day by day. Therefore, urgently need to develop a kind of highly efficient, environment-friendly, cheap production technique, to satisfy the demand of relevant domestic industry as soon as possible. The domestic industrial production of 2,2'-bipyridine is mainly the coupling method, and the difference between different coupling methods li...

AI Technical Summary

Problems solved by technology

In 2004, Chen Jiang of Zhejiang University of Technology reported (Chen Jiang, Synthesis of herbicide diquat and its intermediates [D]. Hangzhou: Zhejiang University of Technology, 2004: 19-45) Raney nickel production 2,2 The production process of '-bipyridine, which uses pyridine as raw material, undergoes a heterogeneous reaction with Raney nickel catalysis, but this process only stays in the theoretical research stage, because Raney nickel will spontaneously combust when exposed to air, and the reaction The yield is not high (7~11%), and the purity of the product is also greatly affected by the improper use of the catalyst

The main disadvantage of this process is that the catalyst is a mixture of three components. The separation of the product and the catalyst after the reaction is very cumbersome, and there are big problems in the recycling of the catalyst and the environmental protection treatment of solid waste. In addition, the whole reaction needs to be processed in sequence. Coupling, alkaline hydrolysis, extraction, pickling, re-alkaline hydrolysis, refining and other steps, the production cycle is long, which is not conducive to large-scale industrial production

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