Preparation method of benzoic acid herbicide dicamba

A technology of herbicides and dicamba, applied in the preparation of carboxylate salts, preparation of organic compounds, chemical instruments and methods, etc.

Inactive Publication Date: 2012-06-27
JIANGSU CHANGQING AGROCHEMICAL CO LTD
View PDF12 Cites 19 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] 4. In Japanese Patent JP4805574, 2,5-dichlorophenol was used as raw material to obtain 2 through etherification, Claisen rearrangement, etherification and oxidation -Methoxy-3,6-dichlorobenzoic acid, its preparation method is ingenious, but its yield is low, and a large amount of three wastes are produced, so the cost is relatively high, and it has not been adopted in industrial production

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0026] One, the synthetic method of 2,5-dichlorophenyl acetate:

[0027] 1. Add 83.32g, 0.5mol 2,5-dichlorophenol (purity 99%) 500ml of toluene solution to a 1000ml four-necked bottle equipped with mechanical stirring, thermometer, condenser, dropping funnel, and water separator, 30.4 g, 0.5mol potassium hydroxide (purity 92%) began to heat up to reflux for about 5 to 6 hours, separated 9 grams of water, and a large amount of white flocculent solids were precipitated in the bottle as potassium 2,5-dichlorophenate, and then cooled to After cooling down at room temperature with a water bath, add 40.9 g.0.51 mol of acetyl chloride (purity 98%) dropwise for about 2 hours. The white flocculent solid disappears, and a white powdery solid precipitates out. Sampling and gas spectrometry analysis. When the 2,5-dichlorophenol was finished, it was filtered, and the mother liquor was distilled to give a dark yellow solid of 103 grams of 2,5-dichlorophenyl acetate, with a content o...

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

A preparation method of a benzoic acid herbicide dicamba relates to the technical filed of pesticide production. The invention employs 2,5-dichlorophenols as a raw material and carries out esterification, Fries rearrangement, etherification and oxidation to obtain 3,6-dichloro-2-methoxybenzoic acid. The synthetic method has simple technology, easily available raw material, low cost, generates little "three wastes (waste gas, waste water and industrial residue)" and is more environment-friendly and more suitable for industrialized production.

Description

technical field [0001] The invention relates to the technical field of pesticide production. Background technique [0002] Dicamba, scientific name 3,6-dichloro-2-methoxybenzoic acid, belongs to the series of benzoic acid herbicides and is a relatively friendly herbicide to the environment. Its production method mostly uses the potassium salt of 2,5-dichlorophenol and carbon dioxide under high pressure conditions to carry out carboxylation, re-esterification, and hydrolysis to obtain dicamba. [0003] In recent years, there are few reports on the synthesis methods of 3,6-dichloro-2-methoxybenzoic acid (dicamba), but there are many reports on its preparation methods in the 1950s to 1970s. The synthesis methods are generally summarized as follows . [0004] 1. In the patent document Ussr345129, 1973; Po1:78848, 1975; us4161611, 2-amino-3,6-dichlorobenzoic acid is used as raw material to synthesize 3,6 after diazotization and etherification with methyl chloride - Dichloro-2-...

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): C07C65/21C07C51/255
Inventor 于国权吉志扬张振明王建荣丁华平
Owner JIANGSU CHANGQING AGROCHEMICAL CO LTD
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