Production technology of 2-methyl-4-chloro-sodium phenoxy acetate

Abstract

A process for preparing 2-methyl-4-chloro-sodium phenoxyacetate from O-phenylcresol, chloroacetic acid, sodium hydroxide and chlorine gas includes such steps as neutralizing reaction, etherifying reaction, chlorating reaction and salting reaction. It can be used as herbicide.

Description

technical field [0001] The invention relates to a new process for chemical production, in particular to a new process for producing 2-methyl-4-chloro-phenoxyethyl sodium. Background technique [0002] The trade name of 2-methyl-4-chloro-phenoxyacetic acid sodium is 2 methyl 4 chlorine (MCPA), which is one of the most commonly used herbicide varieties. It is widely used in rice, wheat, corn and other cereal crop fields to control annual and perennial broad-leaved weeds and sedge weeds. The herbicide has the advantages of wide herbicidal spectrum, good effect, low price, and slow formation of weed resistance. At the same time, it can be used with various herbicides such as sodium pentachlorophenate, fenben, enemy brand, grass-killing, and proturon. , expand the herbicidal spectrum, improve the weeding effect, it is widely used, and the market demand is relatively large. [0003] At present, domestic production of 2-methyl-4-chlorine (MPCA) that is 2-methyl-4-chloro-sodium ph...

AI Technical Summary

Problems solved by technology

[0003] At present, domestic production of 2-methyl-4-chlorine (MPCA) that is 2-methyl-4-chloro-sodium phenoxyacetate all adopts the traditional production process, and the traditional process has the following defects: (1) the chlorination reaction product yield is only 50% about

(2) The product has low purity (about 60%), contains more impurities (NaCL), is easy to absorb moisture and agglomerates, and has poor solubility, so it cannot be directly used in the production of 2-methyl-4-chloramine and ester products. To export standards, so that the development of such products has been subject to certain restrictions

(3) The phenol content is too high, about 4%, the dust and smell are relatively large during mixing, and it is easy to make the mixer stick to the wall

(4) Excessive by-products, such as by-product 2-methyl-6-chlorophenoxyacetic acid up to 18%, have adverse effects on the growth of some corn varieties, and cannot meet the requirements for the development and utilization of related products and their compound preparations

(5) In the production process, the "three wastes" are discharged too much, and the content of harmful substances is too high, causing serious environmental pollution and bringing adverse effects on people's living environment and sustainable development

(6) The material ratio is unreasonable, the conversion rate is low, and the material consumption is too large, which seriously restricts the further development of the enterprise

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