Method for preparing diuron

A technology of diuron and xylene, which is applied in the field of preparation of diuron, can solve the problems of low content, low product yield, difficult separation and purification, etc., to reduce the generation of by-products, benefit environmental protection, and save costs Effect

Inactive Publication Date: 2014-01-29
JIANGSU ANPON ELECTROCHEM
View PDF1 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this method, due to the presence of water in the system, the hydrolysis reaction between m-3,4-dichlorophenylisocyanate and water occurs, and the by-product N,N-bis(3,4-dichlorodiphenyl)urea is produced, resulting in product yield. Low rate, low content, difficult to separate and purify

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for preparing diuron
  • Method for preparing diuron

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] In a 500L dissolution kettle, add 150 kg of xylene and 60 kg of 3,4-dichloroaniline, stir, open the steam valve, slowly raise the temperature to 55°C, and stir for 1 hour. After the 3,4-dichloroaniline is completely dissolved, Drive it into the high gauge slot. In a 500L reaction kettle, add 230 kg of xylene, lower the temperature, pass 12 kg of phosgene, and when the temperature drops to -2°C, add the xylene solution of the above-mentioned 3,4-dichloroaniline dropwise, after 2 hours, stir React for 3-4 hours and raise the temperature to 130°C, then add phosgene until the material is clear and transparent, stop passing phosgene, and use N 2 Catch phosgene and rectify to obtain 68.6 kg of pure 3,4-dichlorophenylisocyanate with a purity of 98.7%.

[0025] In a 500L dissolution kettle, add 250 kg of xylene, add 68.6 kg of 3,4-dichlorophenyl isocyanate prepared above, raise the temperature to 60°C, stir for 1 hour, pass in 18.10 kg of dimethylamine gas, and stir After 2 h...

Embodiment 2

[0027] The preparation of 3,4-dichlorophenylisocyanate is the same as in Example 1.

[0028] In a 500L dissolution kettle, add 220 kg of toluene, add 68.6 kg of 3,4-dichlorophenyl isocyanate prepared above, raise the temperature to 60°C, stir for 1 hour, and introduce 18.10 kg of dimethylamine gas, and stir for 2 hours , when the content of 3,4-dichlorophenylisocyanate is below 0.1wt% of the whole reaction system, the reaction is terminated, filtered by suction, and dried to obtain 82.65 kg of diuron solid, with a content of 99.3% and a yield of 94.8%.

Embodiment 3

[0030] The preparation of 3,4-dichlorophenylisocyanate is the same as in Example 1.

[0031] In a 500L dissolution kettle, add 260 kg of o-dichlorobenzene, add 68.6 kg of 3,4-dichlorophenyl isocyanate prepared above, raise the temperature to 60°C, stir for 1 hour, and feed 18.10 kg of dimethylamine gas , stirred for 2 hours, and ended the reaction when the content of 3,4-dichlorophenylisocyanate was below 0.1wt% of the entire reaction system, suction filtered, and dried to obtain 82.72 kg of diuron solids, a content of 99.2%, and a yield of 94.5%.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a method for preparing diuron. The method comprises the steps of firstly forming 3, 4-dichlorobenzene isocyanate through a reaction of 3, 4-dichloroaniline and phosgene, directly reacting the 3, 4-dichlorobenzene isocyanate with dimethylamine gas and finally preparing the diuron. The method disclosed by the invention has the advantages that the dimethylamine gas is directly introduced into an organic phase to react and a traditional dimethylamine aqueous solution is replaced, so that the decomposition of the 3, 4-dichlorobenzene isocyanate in an aqueous phase is avoided, the forming of by-products is reduced, the cost is saved, wastewater is not produced and environmental protection is benefitted; the purity of the prepared diuron is more than 99% and the total recovery of the 3, 4-dichloroaniline is more than 95%.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, and in particular relates to a preparation method of diuron. Background technique [0002] Diuron, chemical name 3-(3,4-dichlorophenyl)-1,1-dimethylurea, molecular weight: 233.1, pure product is colorless crystalline solid, melting point 158~159℃, easily soluble in Hot alcohol, the solubility in acetone at 27°C is 5.3%, slightly soluble in ethyl acetate, ethanol and hot benzene. Insoluble in water, the solubility in water is 42ppm at 25°C, low solubility in hydrocarbons, stable to oxidation and hydrolysis, used to prevent common weeds in non-cultivated areas, prevent re-spreading of weeds, also used for asparagus, citrus , cotton, pineapple, sugar cane, fruits of temperate trees and shrubs. [0003] Its structural formula is: [0004] [0005] At present, the synthesis method of Diuron mainly includes two steps: [0006] (1) Photochemical reaction of 3,4-dichloroaniline and phosgene to ge...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C07C275/30C07C273/18
Inventor 于春红陈同明王凤朝
Owner JIANGSU ANPON ELECTROCHEM
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap