Green synthesis method of methyl-chloride

A technology of green synthesis and methyl sulfide, which is applied in the field of green synthesis of methyl-chloride, can solve the problems of high environmental protection pressure, easy thermal decomposition, and rapid temperature rise of the reaction system, and achieve easy separation, less three wastes, and easy Effect of treatment

A technology of green synthesis and methyl sulfide, which is applied in the field of green synthesis of methyl-chloride, can solve the problems of high environmental protection pressure, easy thermal decomposition, and rapid temperature rise of the reaction system, and achieve easy separation, less three wastes, and easy Effect of treatment

CN110483568AActive Publication Date: 2019-11-22湖北驰顺化工有限公司 +1
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  • Green synthesis method of methyl-chloride
  • Green synthesis method of methyl-chloride

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preparation example Construction

[0032] A kind of green synthetic method of methyl-chloride, comprises the steps:

[0033] S1. In the reaction system for preparing methyl-chloride with methyl sulfide and chlorine as raw materials, the characteristic that disulfur dichloride can be used to chlorinate methyl sulfide is used to control the amount of chlorine introduced to make the reaction The disulfur dichloride produced in the process continues to react with methyl sulfide to convert to methyl-chloride and sulfur;

[0034] S2. After the reaction is completed, add catalyst A and catalyst B to the reaction system to precipitate the sulfur in the system as loose crystals, separate sulfur and methyl-chloride crude products, and obtain high-purity methyl chloride through vacuum distillation. -chloride. In this technical solution, catalysts A and B must be added at the same time, otherwise it is difficult to realize the precipitation of sulfur or the precipitation rate is low, and the properties of sulfur precipita...

Embodiment 1

[0046] A kind of green synthetic method of methyl-chloride of the present invention, comprises the steps:

[0047] (1) Add 150g (98%) methyl sulfide (O,O-dimethyl S-hydrogen-di Thiophosphoric acid ester), 66g of chlorine gas is passed in about 3 hours at 30-40°C, the reaction tail gas (hydrogen chloride) is absorbed by water, and the chlorine flow is completed.

[0048](2) Heat up to 50°C (increase the temperature to increase the subsequent reaction speed), add 2g of sodium hydroxide, keep warm and stir for 1h, add 75g of 4% mass fraction PDS desulfurizer aqueous solution, stir at constant temperature for 1h, then cool down to 20°C (cool down can increase the crystallization speed), after 2 hours of heat preservation, filter to obtain loose crystalline sulfur, and separate the liquid to obtain the crude methyl-chloride. The crude product was transferred to a distillation flask, and rectified at -0.099 MPa high vacuum at 60°C to obtain 136.2 g of methyl-chloride (purity 99%), ...

Embodiment 2

[0050] A kind of green synthetic method of methyl-chloride of the present invention, comprises the steps:

[0051] (1) Add 300g (98%) methyl sulfide (O,O-dimethyl S-hydrogen-di Phosphorothioate), 132g of chlorine gas is passed in about 2 hours at 30-40°C, the reaction tail gas is absorbed by water, and the chlorine flow is completed.

[0052] (2) Heat up to 50°C and add 3g of sodium hydroxide, keep stirring and react for 1h, add 200g of 3% mass fraction PDS desulfurizer aqueous solution, stir at constant temperature for 0.5h, then cool down to 20°C, keep warm for 1h and filter to obtain loose crystal sulfur. The liquid was separated to obtain the crude product of methyl-chloride. The crude product was transferred to a distillation flask, and rectified at -0.099 MPa high vacuum at 60°C to obtain 268.8 g of methyl-chloride (purity 99%), yield 90.1%.

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Abstract

The invention discloses a green synthesis method of methyl-chloride. The method comprises the following steps of S1, in a reaction system for preparing the methyl-chloride by taking the methyl sulfideand the chlorine as the raw materials, utilizing the characteristic that the disulfur dichloride can chlorinate the methyl sulfide, continuously reacting the disulfur dichloride generated during thereaction process with the methyl sulfide to convert into the methyl-chloride and the sulfur by controlling the introduction amount of the chlorine; and S2, after the reaction is completed, adding a catalyst A and a catalyst B into the reaction system, precipitating the sulfur in the system in the form of loose crystals, separating to obtain the sulfur and a methyl-chloride crude product, and carrying out rectification under vacuum to obtain the high-purity methyl-chloride. According to the method, not only the high-purity methyl-chloride can be prepared, the yield is increased, but also the crystalline sulfur with excellent properties can be obtained and can be reused, a large amount of salt-containing wastewater and the elastic sulfur waste residues are effectively avoided, the pollutioncaused by the waste gas is also avoided, the environmental protection is achieved, and the social benefits and the environmental benefits are remarkable.

Description

technical field [0001] The invention belongs to the technical field of preparation of pesticide intermediates, and in particular relates to a green synthesis method of methyl-chloride. Background technique [0002] O, O-dimethylphosphorothioate chloride (referred to as methyl chloride, the same below) is a special intermediate for the synthesis of phosphorothioate pesticides. Methyl-chloride can be used to prepare nearly twenty kinds of high-efficiency, medium-low toxicity organophosphorus pesticides, such as pirimiphos-methyl, chlorpyrifos-methyl, fenitrothion, tolclofos-methyl, etc. Among them, chlorpyrifos-methyl, chlorpyrifos, and pirimiphos-methyl are high-efficiency and low-toxic organophosphate varieties recommended by the Food and Agriculture Organization of the United Nations (FAO). In recent years, the demand for methyl-chloride in the pesticide market has shown an increasing trend year by year. [0003] At present, the mainstream methyl-chloride synthesis route ...

Claims

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Application Information

Patent Timeline
22 Nov 2019
Publication
CN110483568A
IPC
C07F9/14
CPC
C07F9/14
Inventors
竺来发; 王胜得