Preparation method of 2-methyl-4-sodium chlophenoxycetate

Abstract

The invention provides a preparation method of 2-methyl-4-sodium chlophenoxycetate. The preparation method comprises the following steps: mixing 2-methyl-4-chlorophenoxyacetic acid solid, a sodium-containing compound solid and water in a kneading device or a rake-type drying device with a condensed water absorption device, reacting under sealed conditions to obtain powdery 2-methyl-4-sodium chlophenoxycetate; the molar ratio of the 2-methyl-4-chlorophenoxyacetic acid to a sodium-containing compound to water is 1 to 1.0-1.8 to 0.1 to 1.2. The content of the prepared product, namely 2-methyl-4-sodium chlophenoxycetate, is as high as 93% to 96%, the water content is less than 1.0%, and the prepared product has no pungent phenolic odor. Due to the low water content, a blanking pipe of a packing machine is not blocked when mechanical packaging is performed; because of the high content of the product, no organic impurities enter the product, the probability of phytotoxicity to crops is low and no pollution can be caused to soil.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a preparation method of sodium 2-methyl-4-chlorophenoxyacetate. Background technique [0002] 2-Methyl-4-chlorophenoxyacetic acid, commonly known as 2-methyl-4-chloro, is a phenoxycarboxylic acid pesticide and is a hormone-type, systemic, selective herbicide. The plant of this agent was reported by R Elsade in 1945 Growth-regulating activity, later used as herbicide production by the British Bian Neimen (ICI) company. 2M-4C herbicides are mainly used as stem and leaf treatment agents, used in cereal crops, conifers, non-cultivated land, grass, lawns, etc., to control annual and perennial broad-leaved weeds, such as amaranth, quinoa, cocklebur, and spinach Flowers, purslane, succulents, Persian mother-in-law, wormwood, etc. Most broadleaf crops, especially cotton, are sensitive to these herbicides. 2M4Cl can be used as a soil treatment agent, applied after soybean sow...

AI Technical Summary

Problems solved by technology

[0004] The solubility of 2-methyl-4-chlorine original drug in water is very small, and it cannot be used as a preparation directly. It is usually processed into different dosage forms such as esters and salts. When the dosage form is a low-chain ester, it has strong volatility and is prone to drift damage.

[0006] But there are following problems in this process: 1. in the production, because 30% liquid caustic soda is added dropwise, a large amount of water is brought in, and a large amount of heat energy (steam) is consumed during distillation and concentration; Processing costs; ③The product produced by this process has only 50%-70% of 2-methyl-4-chlor sodium salt content, and the moisture content is greater than 5%, has a pungent phenol smell, and the product appearance is brown to brown; ④Due to the high moisture content and the existence of organic impurities, it is easy to block the feeding pipeline of the packaging machine when packaging with a mechanical packaging machine; Substances are transferred to crops and soil, which may easily cause crop injury and residue, soil pollution, etc.

[0007] And due to the influence of raw materials and production technology for many years, 2,4-chlor sodium salt brine can only achieve 13%-20% active ingredient products, and 2,4-chlor sodium salt soluble powder can only achieve 50% %-70% active ingredients, compounded with other herbicides, poor compatibility

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