Method and device for improving yield and environmental friendliness of prometryn

Abstract

The invention discloses a method and a device for improving yield and environmental friendliness of prometryn, which are used for analyzing a cyclization reaction mechanism and a crystallization mechanism of prometryn, m-xylene is used as a solvent, the solvent polarity and functional group steric hindrance of m-xylene are better matched with the molecular structure of prometryn, the reaction selectivity is higher, and the yield and environmental friendliness of prometryn are improved. The solubility of the prometryn changes more violently along with the temperature, the solubility of the prometryn is lower under the low-temperature condition, and the crystallization yield is higher. The m-xylene does not contain chlorine, the boiling point and the saturated vapor pressure are higher than those of dichloroethane, the VOCs treatment angle is easier to control, the solubility of the prometryn in the xylene is lower than that in the dichloroethane, mother liquor can be used in batches, losses caused by mother liquor scrapping are reduced. Due to thorough reaction, the impurity thiourea content is extremely low and the crystallization stage operation elasticity is large. The concentrated mother liquor loss is low, the cyclization reaction yield is improved, the yield of crystallized hazardous wastes is reduced, the VOCs yield is reduced, and the environmental friendliness of the process is improved.

Description

technical field [0001] The invention relates to the technical field of pesticides, in particular to a method and a device for improving the yield and environmental friendliness of pidiling. Background technique [0002] Pililing is a new type of insect growth regulator with high efficiency, long-lasting effect, strong selectivity and safety. It is a non-biocide pesticide. It protects natural enemies and provides a successful example for the combination of chemical control and biological control. It is mainly used for the control of leafhoppers, planthoppers, whiteflies and scale insects in crops such as rice, vegetables, tea and citrus. It is currently the leading variety for the control of rice planthoppers. At present, the last step of the cyclization reaction of chlorpyrin is the most important to the yield. The solvent used for its production and crystallization is dichloroethane. , and dichloroethane is a haloalkane with strong volatility. It is a key control substanc...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a method for improving the yield and environmental friendliness of dichloride, aiming to solve the problem of adopting dichloroethane as reaction solvent and crystallization solution in the prior art, and its last step yield is on the low side, resulting in More technical problems of crystalline hazardous waste

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