Synthetic method for improving yield of methamidophos intermediate

A synthetic method, the technology of methamidophos, applied in the field of fine chemical production, can solve the problem of not exceeding 75%, and achieve the effect of improving quality standards and high purity

Pending Publication Date: 2020-06-05
安道麦股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Up to now, the production process used by methamidophos manufacturers is basically the same. The content of methamidophos produced according to the process currently used by these enterprises is generally about 73%, and the main impurities are trimethyl ester, spermine and Dimethyl sulfate, the total content of these three impurities in methamidophos products accounts for more than 23%. If these impurities are separated by physical methods, such as using the known methamidophos crystallization method, although it can also increase the amount of methamidophos The content is 80-90%, but the production cost will inevitably increase by 50-100%. This is the fundamental reason why the content of methamidophos products produced by many domestic methamidophos manufacturers for decades still cannot exceed 75%.

Method used

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  • Synthetic method for improving yield of methamidophos intermediate

Examples

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Comparison scheme
Effect test

Embodiment 1

[0020] A kind of synthetic method that is used to improve the productive rate of methamidophos intermediate, it comprises getting O, O-dimethyl thiophosphoramide (spermine for short) 148g (1mol), methylene dichloride 15g, catalyzer methyl iodide 0.2g Put it into a 250mL reaction bottle, add 12.6g of dimethyl sulfate (0.1mol) dropwise, control the reaction temperature at 45-50°C, stir and react for 5 hours to obtain methamidophos with a content of 73.4% and a reaction yield of 92.7%.

Embodiment 2

[0022] A kind of synthetic method that is used to improve the productive rate of methamidophos intermediate, it comprises getting O, O-dimethyl phosphorothioate (spermine for short) 148g (1mol), chloroform 25g, catalyst methyl methanesulfonate 0.1 g was put into a 250mL reaction bottle, 12.6g of dimethyl sulfate was added dropwise, the reaction temperature was controlled at 35-40°C, and the reaction was stirred for 4 hours to obtain methamidophos with a content of 73.4% and a reaction yield of 96.8%.

Embodiment 3

[0024] A kind of synthetic method that is used to improve the productive rate of methamidophos intermediate, it comprises getting O, O-dimethyl thiophosphoramide (spermine for short) 148g (1mol), carbon tetrachloride 35g, catalyst trifluoroform Put 0.05 g of methyl sulfonate into a 250 mL reaction flask, add 12.6 g of dimethyl sulfate dropwise, control the reaction temperature at 30-35°C, and stir for 3 hours to obtain methamidophos with a content of 70.4% and a reaction yield of 97.9%.

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Abstract

The invention discloses a synthetic method for improving the yield of a methamidophos intermediate, and belongs to the technical field of fine chemical production. The method comprises the following steps: reacting O,O-dimethyl phosphoramidothioate with a catalyst and dimethyl sulfate at 25-60 DEG C to obtain methamidophos; wherein a solvent is halogenated alkane, and the catalyst comprises one ofmethyl iodide, methyl methanesulfonate, methyl trifluoromethanesulfonate, trimethylsilyl trifluoromethanesulfonate or isopropyl titanate. The method has the advantages that the process is simple, thereaction time is short, the obtained reaction yield is 90% or above, and the target product purity is high.

Description

technical field [0001] The invention relates to the effective preparation of a reaction intermediate, belongs to the technical field of fine chemical production, and in particular relates to a synthesis method for improving the yield of a methamidophos intermediate. Background technique [0002] Methamidophos is a broad-spectrum insecticide that has been used in China for nearly 30 years. Its high toxicity, as a pesticide variety, will be banned in China, but as an intermediate or raw material for low-toxicity pesticide products such as acephate and methamidophos, and as an important export variety, it is still It has long-lasting and broad production prospects. In the future, the application of methamidophos as an export product and intermediate will require high quality and high content. [0003] Up to now, the production process used by methamidophos manufacturers is basically the same. The content of methamidophos produced according to the process currently used by thes...

Claims

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Application Information

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IPC IPC(8): C07F9/24
CPCC07F9/2408
Inventor 李玉光范锦龙王现刚李卫刘孝平薛光才周用义孙梅
Owner 安道麦股份有限公司
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