阅读说明：本技术 一种提高杀螟丹稳定性的合成方法 (Synthetic method for improving stability of cartap ) 是由 颜泽彬 熊金华 徐飞 周可祥 王玉贵 吴春喜 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种提高杀螟丹稳定性的合成方法,包括如下步骤：将杀虫单溶于氯乙烷中,调节pH,将配置好的杀虫单溶液降温到0度,开始滴加氰化钠溶液,溶液进行分水,将有机相转入醇化釜；在气体发生釜中加入氯化钙,浓盐酸,缓慢升温,将产生的氯化氢气体通入醇化釜中,在醇化釜中转入反应好的二氯乙烷溶液,加入少量水,加入甲醇,通入气体发生釜产生的氯化氢气体,将醇化釜物料转入脱溶釜,开真空,加热升温,加入定量的水,搅拌,至物料全溶,加入定量稀硫酸,趁热转入结晶釜。将转入的物料降温到0度左右,可以抽滤,滤饼为杀螟单盐酸盐。本发明具有成本低、投资小、能耗低、操作简便,产品稳定性大幅提高的优点。(The invention discloses a synthetic method for improving stability of cartap, which comprises the following steps: dissolving monosultap in ethyl chloride, adjusting pH, cooling the prepared monosultap solution to 0 deg.C, dropwise adding sodium cyanide solution, dividing water, and transferring the organic phase into alcoholization kettle; adding calcium chloride and concentrated hydrochloric acid into a gas generation kettle, slowly heating, introducing generated hydrogen chloride gas into an alcoholization kettle, transferring a reacted dichloroethane solution into the alcoholization kettle, adding a small amount of water, adding methanol, introducing the hydrogen chloride gas generated by the gas generation kettle, transferring the alcoholization kettle material into a desolventizing kettle, opening vacuum, heating to raise the temperature, adding a certain amount of water, stirring until the material is completely dissolved, adding a certain amount of dilute sulfuric acid, and transferring into a crystallization kettle while the material is hot. Cooling the transferred material to about 0 ℃, and performing suction filtration to obtain a filter cake which is the single hydrochloride for killing the borers. The invention has the advantages of low cost, small investment, low energy consumption, simple operation and greatly improved product stability.)

1. A synthetic method for improving stability of cartap is characterized by comprising the following steps:

step 1: monosultap solution: dissolving monosultap in chloroethane;

step 2: adjusting the pH value: adding 30% sodium cyanide solution and adding liquid caustic soda to adjust the pH to about 9;

and step 3: addition reaction: cooling the prepared monosultap solution to 0 ℃, starting to dropwise add a sodium cyanide solution, keeping the temperature of the solution at 0-5 ℃ all the time during dropwise adding, keeping the temperature at about 5-10 ℃ after reaction, keeping the temperature for 2 hours, carrying out water diversion on the solution, and transferring an organic phase into an alcoholization kettle;

and 4, step 4: hydrogen chloride generation reaction: adding calcium chloride and concentrated hydrochloric acid into a gas generation kettle, slowly heating, and introducing the generated hydrogen chloride gas into an alcoholization kettle;

and 5: transferring the reacted dichloroethane solution into an alcoholization kettle, adding a small amount of water, adding methanol, heating to maintain the temperature at 10-20 ℃, introducing hydrogen chloride gas generated by a gas generation kettle, and preserving the heat for 1 hour after the reaction is finished;

step 6: desolventizing: transferring the material in the alcoholization kettle to a desolventizing kettle, vacuumizing, heating to raise the temperature, adding a certain amount of water after the solvent is completely removed clearly visible in the reaction kettle when the temperature is 60 ℃, stirring, raising the temperature to 60-70 ℃ until the material is completely dissolved, adding a certain amount of dilute sulfuric acid, and transferring to a crystallization kettle while the material is hot.

And 7: and (3) crystallization: cooling the transferred material to about 0 ℃, and performing suction filtration to obtain a filter cake which is the single hydrochloride for killing the borers.

2. The method for synthesizing cartap with improved stability according to claim 1, wherein the NaCN solution is heated to 25 ℃ in step 2.

3. The method for synthesizing cartap with improved stability according to claim 1, wherein the mole ratio of sodium cyanide to monosultap in step 3 is 2.05-2.1.

4. The method for synthesizing cartap with improved stability according to claim 1, wherein the molar amount of water is 2.5 times of the molar amount of monosultap in step 5, and the molar amount of methanol is 3 times of the molar amount of monosultap.

5. The method for synthesizing cartap according to claim 1, wherein the amount of sulfuric acid added in step 6 is determined according to the requirement of customers on the pH value of the product, and the pH value is less than or equal to 3.3: monosultap: sulfuric acid 1 Kmol: 0.7 KG; pH 3.3-3.7: monosultap: sulfuric acid 1 Kmol: 0.5 KG.

6. The method for synthesizing cartap according to claim 5, wherein after stirring for 10 minutes, the pH is measured again and then transferred to a crystallization kettle, and the pH is higher than the product pH required by customers, so as to ensure that the dried product pH meets the requirement.

Technical Field

The invention relates to a synthetic method of cartap, in particular to a synthetic method for improving stability of cartap.

Background

Cartap, also known as Badan or Padan, is a variety of nereistoxin insecticides, has good effect on pest poisoning, has stomach poisoning and contact poisoning effects, and also has functions of systemic absorption and ovicidal action. The insecticidal principle is the same as that of dimehypo, belongs to nerve conduction blocking agents, and can be converted into nereistoxin to kill insects when entering the bodies of the insects. Cartap is mainly used for crops such as rice, vegetables, fruit trees, tea trees and the like, and is named as cartap because of the cartap. Cartap appears as a white powder with a melting point of 179 and 181 ℃. Is soluble in water, slightly soluble in methanol and ethanol, and insoluble in organic solvents such as acetone, diethyl ether, ethyl acetate, chloroform, and benzene. Stable at normal temperature and under acidic condition, and unstable under alkaline condition.

Cartap is usually prepared as hydrochloride, white crystal in appearance and slight peculiar smell. Decomposing at 183-183.5 deg.C, and melting point (raw material) is 179-181 deg.C. Slightly soluble in methanol, insoluble in ethanol, and insoluble in organic solvents such as diethyl ether, acetone, chloroform, and benzene. The solubility in water at 25 ℃ was 200 g/L. Is stable in an acidic medium, is unstable in an alkaline medium, and is corrosive to metals such as iron.

The first conventional synthetic method for cartap at the present stage comprises the following steps:

1. monosultap solution: monosultap is dissolved in ethyl chloride.

2. Adding: 30% sodium cyanide solution (heated to 25 ℃) is added with caustic soda to adjust the pH to about 9.

3. Addition reaction: cooling the prepared monosultap solution to 0 ℃, starting to dropwise add a sodium cyanide solution, keeping the temperature of the solution at 0-5 ℃ all the time during dropwise adding, keeping the temperature at about 5-10 ℃ after reaction for 2 hours (the molar ratio of sodium cyanide to monosultap is 2.05-2.1), dividing water into the solution, and transferring the organic phase into an alcoholization kettle.

5. Hydrogen chloride generation reaction: adding phosphorous acid into a gas generation kettle, dropwise adding concentrated hydrochloric acid, and introducing the generated hydrogen chloride gas into an alcoholization kettle.

4. Transferring the reacted dichloroethane solution into an alcoholization kettle, adding a small amount of water (the molar weight of water is 2.5 times of the molar weight of the monosultap), adding methanol (the molar weight is 3 times of the molar weight of the monosultap), and heating to maintain the temperature at 10-20 ℃. Introducing hydrogen chloride gas generated by the gas generation kettle. After the reaction is finished, the temperature is kept for 1 hour

5. Desolventizing: transferring the material in the alcoholization kettle to a desolventizing kettle, vacuumizing, heating to raise the temperature, and adding a certain amount of water after the solvent is completely removed clearly visible in the reaction kettle when the temperature is 60 ℃. And transferring the hot solution into a crystallization kettle.

6. And (3) crystallization: cooling the transferred material to about 0 ℃, and performing suction filtration to obtain a filter cake which is the single hydrochloride for killing the borers.

The technical parameters of cartap synthesized by the first process are shown in the following table 1:

table 1: technical parameters of the existing first cartap synthesis process

The process for preparing the hydrogen chloride gas by using the phosphorous acid has the advantages that the phosphorus content in the wastewater is more, the wastewater treatment cost is higher, particularly, the phosphorous acid price is far higher than that of calcium chloride, the wastewater generated by the process contains more phosphorus, certain pressure is caused for environmental protection, and the wastewater treatment cost is higher.

The second conventional synthetic method for cartap at the present stage comprises the following steps:

1. monosultap solution: monosultap is dissolved in ethyl chloride.

2. 30% sodium cyanide solution (heated to 25 ℃) is added with liquid alkali to adjust the pH to about 9.

3. Addition reaction: cooling the prepared monosultap solution to 0 ℃, starting to dropwise add a sodium cyanide solution, keeping the temperature of the solution at 0-5 ℃ all the time during dropwise adding, keeping the temperature at about 5-10 ℃ after reaction for 2 hours (the molar ratio of sodium cyanide to monosultap is 2.05-2.1), dividing water into the solution, and transferring the organic phase into an alcoholization kettle.

5. Hydrogen chloride generation reaction: calcium chloride and concentrated hydrochloric acid are added into a gas generation kettle, and the generated hydrogen chloride gas is introduced into an alcoholization kettle, and the temperature is slowly increased in the process.

4. Transferring the reacted dichloroethane solution into an alcoholization kettle, adding a small amount of water (the molar weight of water is 2.5 times of the molar weight of the monosultap), adding methanol (the molar weight is 3 times of the molar weight of the monosultap), and heating to maintain the temperature at 10-20 ℃. Introducing hydrogen chloride gas generated by the gas generation kettle. After the reaction is finished, the temperature is kept for 1 hour

5. Desolventizing: transferring the material in the alcoholization kettle to a desolventizing kettle, vacuumizing, heating to raise the temperature, and adding a certain amount of water after the solvent is completely removed clearly visible in the reaction kettle when the temperature is 60 ℃. And transferring the hot solution into a crystallization kettle.

6. And (3) crystallization: cooling the transferred material to about 0 ℃, and performing suction filtration to obtain a filter cake which is the single hydrochloride for killing the borers. The products obtained by the process route meet the national standard. Technical indexes of cartap technical grade: (national standards).

The technical parameters of cartap synthesized by the second process are as follows:

table 2: technical parameters of the existing second cartap synthesis process

The second synthesis route is the best synthesis route on the market at present, the generated wastewater does not contain phosphorus and the like, but the process has the defect that the PH of the obtained product is not in the range required by customers. In particular, some requirements are that the pH is less than 3.7, which cannot be met by the above process.

Disclosure of Invention

The invention aims to provide a synthetic method for improving the stability of cartap, which can solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

a synthetic method for improving stability of cartap comprises the following steps:

step 1: monosultap solution: dissolving monosultap in chloroethane;

step 2: adjusting the pH value: adding 30% sodium cyanide solution and adding liquid caustic soda to adjust the pH to about 9;

and step 3: addition reaction: cooling the prepared monosultap solution to 0 ℃, starting to dropwise add a sodium cyanide solution, keeping the temperature of the solution at 0-5 ℃ all the time during dropwise adding, keeping the temperature at about 5-10 ℃ after reaction, keeping the temperature for 2 hours, carrying out water diversion on the solution, and transferring an organic phase into an alcoholization kettle;

and 4, step 4: hydrogen chloride generation reaction: adding calcium chloride and concentrated hydrochloric acid into a gas generation kettle, slowly heating, and introducing the generated hydrogen chloride gas into an alcoholization kettle;

and 5: transferring the reacted dichloroethane solution into an alcoholization kettle, adding a small amount of water, adding methanol, heating to maintain the temperature at 10-20 ℃, introducing hydrogen chloride gas generated by a gas generation kettle, and preserving the heat for 1 hour after the reaction is finished;

step 6: desolventizing: transferring the material in the alcoholization kettle to a desolventizing kettle, vacuumizing, heating to raise the temperature, adding a certain amount of water after the solvent is completely removed clearly visible in the reaction kettle when the temperature is 60 ℃, stirring, raising the temperature to 60-70 ℃ until the material is completely dissolved, adding a certain amount of dilute sulfuric acid, and transferring to a crystallization kettle while the material is hot.

And 7: and (3) crystallization: cooling the transferred material to about 0 ℃, and performing suction filtration to obtain a filter cake which is the single hydrochloride for killing the borers.

Further, the NaCN solution is heated to 25 degrees Celsius in step 2.

Further, the molar ratio of sodium cyanide to monosultap in step 3 is 2.05-2.1.

Further, in the step 5, the molar amount of water is 2.5 times of the molar amount of the monosultap, and the molar amount of methanol is 3 times of the molar amount of the monosultap.

Further, the amount of the sulfuric acid added in the step 6 is equal to or less than 3.3 according to the requirement of a client on the pH value of the product: monosultap: sulfuric acid 1 Kmol: 0.7 KG; pH 3.3-3.7: monosultap: sulfuric acid 1 Kmol: 0.5 KG.

And further, after stirring for 10 minutes, re-measuring the pH value to meet the requirement, and transferring the material to a crystallization kettle, wherein the pH value is higher than the product pH value required by a customer, so as to ensure that the dried product pH value meets the requirement.

Compared with the prior art, the invention has the beneficial effects that:

the invention adopts a method for preparing hydrogen chloride by calcium chloride and dilute hydrochloric acid and a method for increasing pH by adding a small amount of dilute sulfuric acid. Has the advantages of low cost, low investment, low energy consumption, simple operation and greatly improved product stability. More importantly, the method can adjust the pH value randomly according to the requirements of customers, the pH value of the cartap product is controlled to be relatively stable at a high temperature of between 3.0 and 4.0, most cartap raw medicines are exported to tropical or subtropical areas of southeast Asia, the temperature is higher than 30 ℃ throughout the year, if the pH value of the cartap raw medicines is higher than 4.0, the stability is relatively poor and the cartap is easy to inflate, and certain danger can be generated due to the inflation in both barreling and bagging, so that the method can greatly reduce the goods return phenomenon caused by poor stability of the product, can not cancel orders due to the fact that the pH value does not meet the requirements, and is beneficial to stabilizing the occupancy rate of the market.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A synthetic method for improving stability of cartap comprises the following steps:

step 1: monosultap solution: dissolving monosultap in chloroethane;

step 2: adjusting the pH value: adding 30% sodium cyanide solution (heated to 25 ℃) and adding liquid caustic soda to adjust the pH to about 9;

and step 3: addition reaction: cooling the prepared monosultap solution to 0 ℃, starting to dropwise add a sodium cyanide solution, keeping the temperature of the solution at 0-5 ℃ all the time during dropwise adding, keeping the temperature at about 5-10 ℃ after reaction for 2 hours (the molar ratio of sodium cyanide to monosultap is 2.05-2.1), dividing water into the solution, and transferring the organic phase into an alcoholization kettle;

and 4, step 4: hydrogen chloride generation reaction: adding calcium chloride and concentrated hydrochloric acid into a gas generation kettle, slowly heating, and introducing the generated hydrogen chloride gas into an alcoholization kettle;

and 5: transferring the reacted dichloroethane solution into an alcoholization kettle, adding a small amount of water (the molar weight of the water is 2.5 times of the molar weight of the insecticidal unit), adding methanol (the molar weight is 3 times of the molar weight of the insecticidal unit), heating to maintain the temperature at 10-20 ℃, introducing hydrogen chloride gas generated by a gas generation kettle, and preserving the temperature for 1 hour after the reaction is finished;

step 6: desolventizing: transferring the material of the alcoholization kettle into a desolventizing kettle, vacuumizing, heating to raise the temperature, when the temperature is 60 ℃ fast, clearly showing that the solvent is completely removed in the reaction kettle, adding quantitative water, stirring, raising the temperature to 60-70 ℃ until the material is completely dissolved, adding quantitative dilute sulfuric acid, wherein the amount of the added sulfuric acid is equal to or less than 3.3 according to the requirement of a client on the pH value of the product: monosultap: sulfuric acid 1 Kmol: 0.7 KG; pH 3.3-3.7: monosultap: sulfuric acid 1 Kmol: 0.5 KG. Stirring for 10 minutes, re-measuring the pH value to meet the requirement, transferring the material to a crystallization kettle, ensuring that the pH value of the dried product meets the requirement, and transferring the product to the crystallization kettle while the product is hot.

And 7: and (3) crystallization: cooling the transferred material to about 0 ℃, and performing suction filtration to obtain a filter cake which is the single hydrochloride for killing the borers.

The technical parameters of cartap synthesized by the process are as follows 3:

table 3: the technical parameters of the process for synthesizing cartap

If the pH is more than 4.5, the required requirement can be met by increasing the drying temperature, but the cartap raw medicine with the pH more than 4.5 has poor stability, is easy to expand and has reduced content. The air expansion rate reaches more than 60 percent after the air temperature is higher than 30 ℃ and the storage for one month. The following is a set of different pH heat storage tests at 50 degrees.

Table 4: heat storage test at 50 ℃ at various pH values

The swelling rate between pH 3.0 and 3.7 is zero and the content is relatively stable, but it should be noted that if the pH is lower than 3.0, the product is easy to harden, so the pH of high content cartap is best controlled between 3.0 and 4.0.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical solutions and the inventive concepts of the present invention within the technical scope of the present invention.