Method for preparing pyridine-2-carbonitrile by using 2-OP rectification residue

Abstract

According to the present invention, 2-OP rectification residue is used as a raw material, phosphorylated zeolite and / or phosphorylated silica is used as an in-situ catalytic cracking catalyst, a mixture of alumina, zinc oxide, boric acid, cobalt acetate and silica is used as a catalytic dehydration catalyst, a mixture of sulfamic acid, phosphorus pentasulfide, phosphorus pentoxide and bis(trichloromethyl)carbonate is used as a dehydration agent, and a process comprising an in situ catalytic cracking and pressure reducing distillation process, a catalytic dehydration and pressure reducing distillation process and a rectification process is performed to obtain the pyridine-2-carbonitrile product with the mass percentage of more than or equal to 99%, wherein the yield is 40-60% based on the mass of the 2-OP rectification residue.

Description

technical field [0001] The method for preparing pyridine-2-carbonitrile by using 2-OP rectification residue involved in the present invention is a novel method for resourceful and efficient utilization of chemical by-products in the field of organic synthesis for the preparation of fine organic chemicals. Background technique [0002] 2-OP, the chemical name is 2-cyanopyridine, pyridine-2-carbonitrile, 2-pyridinecarbonitrile, the CAS number is 100-70-9, it is a white to light brown needle with a melting point of 24-27°C A crystalline solid. As an important intermediate, 2-OP is widely used in the synthesis of various fine organic chemicals such as medicines, pesticides and dyes. These typical fine organic chemicals synthesized from 2-OP can show many outstanding properties: for example, the new herbicide picloram synthesized from 2-OP has low dosage, high selectivity, low toxicity, It has the characteristics of small residual amount and short residual period in soil and pl...

AI Technical Summary

Problems solved by technology

For the residues generated during these rectification processes, the existing treatment methods are as hazardous solid wastes, which are treated as hazardous solid wastes through high-temperature incineration and then landfilled or mineralized. This treatment method not only consumes a lot of energy, but also It is often not possible to truly achieve the harmlessness of the distillation residue

At the same time, according to the analysis of the process of preparing 2-OP by catalytic ammoxidation of 2-picoline, there may be organic compounds such as pyridine-2-carboxamide and pyridine-2-carbaldehyde or their high-temperature polymerization in this distillation residue. Therefore, the disposal of this distillation residue by direct high-temperature incineration also prevents the resources from being effectively utilized.

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