Novel process for producing chlopyrifos from pyridone by using aqueous phase method

Abstract

The invention relates to a novel process for producing chlopyrifos from pyridone by using an aqueous phase method, and belongs to the field of chemical synthesis. The novel process is finished by the following steps of mixing trichloro-acetic chloride, acrylonitrile and a solvent according to a certain molar ratio to form the pyridine under the effect of a catalyst; putting desalinized water, pyridone, sodium chloride, caustic soda flake (adjusting pH value of the system within 8 to 10), boric acid, an emulsifier and a phase-transfer catalyst into a condensation kettle successively; stirring uniformly; adding a certain amount of 0,0-diethyl thiophosphoryl chloride slowly; reacting at a temperature of 45-50 DEG C to form a chlopyrifos solution; layering; dehydrating; press filtering; cooling; crystallizing; centrifuging for separation and drying to obtain a raw powder of the chlopyrifos with a purity higher than 99%. The novel process reduces production cost, has little process wastewater and can synthesize the raw powder of the chlopyrifos with relatively high purity.

Description

technical field [0001] The invention relates to a new process for preparing chlorpyrifos, which belongs to the field of chemical synthesis. Background technique [0002] The chemical name of chlorpyrifos is 0,0-diethyl-0-(3,5,6,-trichloro-2-pyridyl)phosphorothioate. It is a high-efficiency broad-spectrum, low-to-medium toxicity, and safe organophosphorus insecticide and acaricide. It is one of the better products to replace highly toxic pesticides. It can effectively control borers on vegetables, corn, tea, fruit trees, flowers, etc. , leaf rollers, leaf miners, cotton bollworms, armyworms, scale insects, aphids, thrips, leafhoppers and various mites, and can also control underground pests and parasites outside livestock. It has broad application prospects and is an alternative The first species of highly toxic pesticides. [0003] According to the reaction conditions, the production methods of chlorpyrifos are generally divided into organic solvent method, dual solvent me...

AI Technical Summary

Problems solved by technology

Most of the organic solvent methods use dichloromethane and benzene as solvents. The test results show that not only the yield is not improved, but also the solvent consumption is large, the loss is serious, and the production cost is increased.

Although the two-solvent method can better inhibit the hydrolysis of 0,0-diethylphosphorothioate chloride, this method also needs to consume organic solvents, which causes a lot of pollution to the environment, and the organic solvents are highly toxic and will damage human health and increase production costs

The aqueous phase method can well overcome the shortcomings of the organic solvent method and the dual-solvent method that consume a large amount of organic solvents, increase production costs, and cause great environmental pollution.