Synthesis method of thiodicarb

A synthesis method and technology of thiodicarb, applied in the direction of organic chemistry, etc., can solve the problems of poor thermal storage stability, many by-products, shortened reaction time, etc. economic effect

Active Publication Date: 2021-03-12
潍坊海邦化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method is based on laboratory test data, and mainly has the following disadvantages: (1) the reaction time is long, and only the synthesis process needs more than 8 hours; (2) the yield is low, and the highest yield does not exceed 85.3%; Chinese patent CN111054278A proposes the use of Pyridine and sulfur dichloride synthesized ligand, methomyl, catalyst, solvent xylene are the method for the continuous synthesis of thiodicarb as raw materials, although the continuous synthesis process shortens the reaction time, but does not provide thiodicarb yield. rate data, only the content data of methomyl and thiodicarb for sampling analysis are given
This method has the following deficiencies: (1) the content of methomyl in the prepared thiodicarb product is relatively high, and the minimum content in the examples is 0.67%
[0015] (3) The reaction time is long, the existing intermittent production process, thiodicarb only synthesis process and its reaction time is 8-20 hours;
[0016] (4) The prepared thiodicarb has poor heat storage stability;
[0017] (5) There are too many by-products with different structures during the synthesis of thiodicarb, which directly affects the product purity, melting point (melting range) and other indicators;

Method used

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  • Synthesis method of thiodicarb
  • Synthesis method of thiodicarb
  • Synthesis method of thiodicarb

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0054] 1. Prepare materials

[0055] 295Kg of xylene is sucked into the synthesis kettle by vacuum, and the stirring is started;

[0056] Metering SCl 2 Liquid 141Kg, pumped into the high tank by vacuum;

[0057] Measure 104Kg of pyridine, and pump it into the synthesis kettle;

[0058] Measure methomyl 400Kg (content 97.3%), stand-by;

[0059] Measure 1.6Kg of catalyst trialkyl tertiary amine;

[0060] 2. Ligand synthesis

[0061] Put refrigerant liquid into the jacket of the synthetic kettle for use, cool down the temperature in the kettle to -4°C, and start adding SCl dropwise 2 , control the rate of addition, the reaction temperature was maintained at 3°C, and the addition time was controlled at 90 minutes. SCl 2 After the dropwise addition, continue to stir for 20 minutes;

[0062] 3. Thiodicarb synthesis

[0063] Drain the refrigerant in the jacket of the synthetic kettle, add 400Kg of methomyl and 1.6Kg of catalyst from the manhole, then stir for 20 minutes, fe...

Embodiment 2

[0079] 1. Prepare materials

[0080] 298Kg of xylene is sucked into the synthesis kettle by vacuum, and the stirring is started;

[0081] Metering SCl 2 Liquid 153Kg, pumped into the high tank by vacuum;

[0082] Measure 108Kg of pyridine, and pump it into the synthesis kettle;

[0083] Measure methomyl 400Kg (content 97.3%), stand-by;

[0084] Measure 2Kg of catalyst and set it aside.

[0085] 2. Ligand synthesis

[0086] Put refrigerant liquid into the jacket of the synthetic kettle for use, cool down the temperature in the kettle to -3°C, and start adding SCl dropwise 2 , control the rate of addition, the reaction temperature was maintained at 4 ° C, and the time of addition was controlled at 100 minutes. SCl 2 After the dropwise addition was complete, stirring was continued for 25 minutes.

[0087] 3. Thiodicarb synthesis

[0088] Drain the frozen liquid in the jacket of the synthetic kettle, add 400Kg of methomyl and 2Kg of catalyst from the manhole, then stir fo...

Embodiment 3

[0102] 1. Prepare materials

[0103] 370Kg of xylene is sucked into the synthesis kettle by vacuum, and the stirring is started;

[0104] Metering SCl 2 Liquid 163Kg, pumped into the high tank by vacuum;

[0105] Meter 120Kg of pyridine and pump it into the synthesis kettle;

[0106] Measure methomyl 450Kg (content 97.3%), stand-by;

[0107] Measure 2.5Kg of catalyst and set it aside.

[0108] 2. Ligand synthesis

[0109] Put refrigerant into the jacket of the synthetic kettle for use, cool down the temperature in the kettle to -2°C, and start adding SCl dropwise 2 , control the rate of addition, the reaction temperature was maintained at 5 ° C, and the time of addition was controlled at 110 minutes. SCl 2 After the dropwise addition was complete, stirring was continued for 20 minutes.

[0110] 3. Thiodicarb synthesis

[0111] Drain the frozen liquid in the jacket of the synthesis kettle, add 400Kg of methomyl and 2.5Kg of catalyst from the manhole, then stir for 25 min...

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Abstract

The invention provides a synthesis method of thiodicarb, and the method comprises the following steps: synthesizing a ligand, and synthesizing thiodicarb. According to the invention, trialkyl tertiaryamine is used as a catalyst for synthesis of thiodicarb, and during synthesis of thiodicarb, the reaction pressure is increased, and the industrial synthesis reaction time is shortened to 5 hours; inthe thiodicarb synthesis process, the temperature is controlled in three stages, the reaction temperature is controlled at 10-15 DEG C for 1-1.5 hours, the reaction temperature is controlled at 20-25DEG C for 1-1.5 hours, the reaction temperature is controlled at 30-35 DEG C for 1-2 hours, and gradient heating is adopted, so the defect of multiple side reactions caused by always reacting at a relatively high temperature is avoided.

Description

technical field [0001] The invention belongs to the technical field of pesticide compound synthesis, and in particular relates to a production method in which methomyl is synthesized by batch reaction in the presence of a catalyst to improve the yield, purity and thermal storage stability of thiodicarb. Background technique [0002] Thiodicarb, also known as dimethomyl, thiodicarb, and lavin, is an insecticide further improved on the basis of methomyl, that is, two methomyls are connected through a thioether chain. Molecules form biscarbamate. Thiodicarb mainly has gastric poisoning effect on pests, has almost no contact effect, no fumigation and systemic effect, has strong selectivity, and has a short residual effect in soil. Its mechanism of action lies in nerve obstruction, that is, by inhibiting the activity of acetylcholinesterase, it hinders the reactivation of the conduction material in nerve fibers, resulting in the death of pest poisoning. Thiodicarb has special e...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C381/08
CPCC07C381/08
Inventor 赵万喜刘昕赵旭张文佩王瑞华王晨希李光磊
Owner 潍坊海邦化工有限公司
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