Method for manufacturing catalyst used for synthesizing 2-picoline

Abstract

The invention discloses a catalyst with high safety for synthesizing 2-methyl pyridine and a preparation method for the catalyst. The preparation method comprises the following steps: tetrahydrofuran and sodamide are added in a sodium salt kettle, cyclopentadiene is dripped at temperature of 0 to 45 DEG C, the reaction is kept for 0.5 to 3 hours to prepare cyclopentadienylsodium; anhydrous cobaltous chloride is added in the synthesis kettle after tetrahydrofuran is added, and stirred for 30 to 40 minutes, then the prepared cyclopentadienylsodium is added, back flowing of the liquid is kept under 60 to 70 DEG C, the stirring and reaction is kept for 1 to 2 hours, the reaction for preparing the catalyst is finished; after the backflow is finished, the solvent is recycled and heated to 65 to75 DEG C, when the liquid flow volume is reduced, the vacuum pressure distillation is started to recycle solvent, acetonitrile is continuously stirred and added when no liquid exists in the kettle, after being stirred for 1 hour under the room temperature, sodium chloride is removed to obtain the catalyst in mixture state. The invention has a simple reaction process, eliminates the demanding requirements and complexity of the synthesizing process for organic Co catalyst crystal.

Description

Technical field: [0001] The invention relates to a catalyst used in the synthesis of chemical products, in particular to a catalyst used for synthesizing 2-picoline. Background technique: [0002] 2-picoline is an intermediate in the chemical industry, mainly used in medicine and other industries. The 2-picoline currently used in my country is mainly imported. The key problem in its synthesis is the catalyst dicobaltene used in the synthesis process. They are all crystalline cobaltocenes, and their production process is relatively complicated, and the process conditions are harsh. The final crystallization of cobaltocenes needs to be realized under high vacuum conditions. In particular, it should be pointed out that the activity of crystalline cobaltocene is very high, it is afraid of light, heat and easy to decompose, afraid of acid gas, easy to oxidize and spontaneously combustible in the air. It is difficult to guarantee the quality and quality, and it is difficult to ach...

AI Technical Summary

Problems solved by technology

[0002] 2-picoline is an intermediate in the chemical industry, mainly used in medicine and other industries. The 2-picoline currently used in my country is mainly imported. The key problem in its synthesis is the catalyst dicobaltene used in the synthesis process. Both are crystalline cobaltocenes, and their production process is relatively complicated, and the process conditions are harsh. The final crystallized cobaltocenes need to be realized under high vacuum conditions.

In particular, it should be pointed out that the activity of crystalline cobaltocene is very high, it is afraid of light, heat and easy to decompose, afraid of acid gas, easy to oxidize and spontaneously combustible in the air. It is difficult to guarantee the quality and quality, and it is difficult to achieve industrial production. It can only be produced experimentally on a laboratory scale. For example, the state of the prior art can be seen in US patent documents US4556714, US4320066 or German patent DE1223839

The above documents basically use more than two times of repeated solvent dissolution, filtration, concentration, low vacuum solvent recovery, low vacuum drying, and low temperature crystallization at -80°C. This has a great impact on the activity of the catalyst. The second is the industrial scale. Production is quite difficult in industry