阅读说明：本技术 二甲草胺合成新工艺 (Novel synthetic process of dimethachlor ) 是由 吴克崇 吴贯中 郭胜 郭凯杰 于 2020-07-19 设计创作，主要内容包括：本发明公开了一种二甲草胺合成新工艺,包括以下步骤：步骤S1：将氯乙基甲基醚与二甲基苯胺投入反应釜进行N-烷基化反应,用导热油升温反应,反应结束后静置分层,油层进入下步精馏,水层排污,得到N-烷基化产物；步骤S2：将N-烷基化产物加入精馏塔釜中进行精馏,将过量二甲基苯胺分离出来去套用,接收合格的胺醚用于下步反应,少量高沸点残渣直接排渣,得到N-(2-甲氧基乙基)-2,6-二甲基苯胺产物；步骤S3：将N-(2-甲氧基乙基)-2,6-二甲基苯胺产物计量后投入酰化釜进行酰化反应。本发明设计的二甲草胺合成工艺可提高生产效率,降低生产成本,同时还可改善生产环境,而且还可以明显提高二甲草胺的收率。(The invention discloses a novel synthetic process of dimethachlor, which comprises the following steps: step S1: putting chloroethyl methyl ether and dimethylaniline into a reaction kettle for N-alkylation reaction, heating with heat conducting oil for reaction, standing for layering after the reaction is finished, rectifying an oil layer next step, discharging sewage from a water layer, and obtaining an N-alkylation product; step S2: adding the N-alkylated product into a rectifying tower kettle for rectification, separating out excessive dimethylaniline for reuse, receiving qualified amine ether for the next reaction, and directly discharging slag from a small amount of high-boiling-point residues to obtain an N- (2-methoxyethyl) -2, 6-dimethylaniline product; step S3: the N- (2-methoxyethyl) -2, 6-dimethylaniline product is measured and then put into an acylation kettle for acylation reaction. The synthetic process of the alachlor designed by the invention can improve the production efficiency, reduce the production cost, improve the production environment and obviously improve the yield of the alachlor.)

1. The novel process for synthesizing the alachlor is characterized by comprising the following steps of:

step S1: preparation of the N-alkylated product: putting chloroethyl methyl ether and dimethylaniline into a reaction kettle for N-alkylation reaction, heating with heat conducting oil for reaction, standing for layering after the reaction is finished, rectifying an oil layer next step, discharging sewage from a water layer, and obtaining an N-alkylation product;

step S2: preparing amine ether: adding the N-alkylated product obtained in the step S1 into a rectifying tower kettle for rectification, separating excessive dimethylaniline for reuse, receiving qualified amine ether for the next reaction, and directly discharging a small amount of high-boiling-point residues to obtain an N- (2-methoxyethyl) -2, 6-dimethylaniline product;

step S3: acylation reaction: metering the N- (2-methoxyethyl) -2, 6-dimethylaniline product obtained in the step S2, then putting the product into an acylation kettle for acylation reaction, then putting the solvent toluene and liquid alkali, slowly dripping metered chloroacetyl chloride, preserving heat for reaction after dripping, putting the product into a washing kettle for water washing, putting an upper oil layer into a desolventizing process, and performing decontamination water treatment on a water layer to obtain a dimethachlor toluene solution;

step S4: and (4) allowing the washed dimethachlor toluene solution obtained in the step (S3) to enter a lifting membrane for desolventizing, and removing the solvent for reuse, thereby finally obtaining the dimethachlor crude oil.

2. The new dimethachlor synthesis process as claimed in claim 1, wherein in step S1, said reaction kettle is a 500 l stainless steel autoclave, and the raw materials used in the N-alkylation reaction process are respectively 3kmol of 2, 6-dimethylaniline, 1kmol of chloroethyl methyl ether, and 1kmol of 40% aqueous sodium hydroxide solution.

3. The new process for synthesizing dimethachlor according to claim 1, wherein in the step S1, nitrogen in the reaction kettle is replaced three times, the temperature of the heat transfer oil is 170 ℃, and the reaction time is 6 hours.

4. The novel process for synthesizing dimethachlor as claimed in claim 1, wherein in step S1, when the reaction kettle is kept still for layering, the oil phase is washed with water and then rectified to obtain an amine ether intermediate.

5. The new process for synthesizing dimethachlor as claimed in claim 1, wherein in step S3, after the solvent toluene is added into the reaction kettle, the PH of the system is adjusted to 6-7 by liquid alkali, the temperature is controlled to 20-25 ℃, and then metered chloroacetyl chloride is slowly added dropwise.

6. The novel process for synthesizing dimethachlor according to claim 5, wherein in the step S3, chloracetyl chloride is dripped and then the reaction is carried out for 1 hour.

Technical Field

The invention relates to the technical field of chemistry and chemical engineering, in particular to a novel synthetic process of dimethachlor.

Background

Dimethachlor is an acetamide herbicide, has a chloroacetamide structure, is a cell division inhibitor, affects cell growth by inhibiting the synthesis of long-chain fatty acids, has selectivity, and is mainly absorbed through hypocotyls and buds. In acetamide herbicides, chloroacetamides occupy the leading position, and have the advantages of relative high efficiency, low toxicity and low residue, so that the chloroacetamides occupy the important position in the pesticide industry and are more and more widely applied.

However, in the prior art, the reaction steps in the process of synthesizing the dimethachlor are complex and difficult to control, the production efficiency is low, the production cost is high, and the environmental pollution is serious, so a new technology for synthesizing the dimethachlor is provided for solving the problems.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a novel synthetic process of dimethachlor.

The invention provides a novel synthetic process of dimethachlor, which comprises the following steps:

step S1: preparation of the N-alkylated product: putting chloroethyl methyl ether and dimethylaniline into a reaction kettle for N-alkylation reaction, heating with heat conducting oil for reaction, standing for layering after the reaction is finished, rectifying an oil layer next step, discharging sewage from a water layer, and obtaining an N-alkylation product;

step S2: preparing amine ether: adding the N-alkylated product obtained in the step S1 into a rectifying tower kettle for rectification, separating excessive dimethylaniline for reuse, receiving qualified amine ether for the next reaction, and directly discharging a small amount of high-boiling-point residues to obtain an N- (2-methoxyethyl) -2, 6-dimethylaniline product, namely N- (2-methoxyethyl) -2, 6-dimethylaniline, which is called amine ether for short;

step S3: acylation reaction: metering the N- (2-methoxyethyl) -2, 6-dimethylaniline product obtained in the step S2, then putting the product into an acylation kettle for acylation reaction, then putting the solvent toluene and liquid alkali, slowly dripping metered chloroacetyl chloride, preserving heat for reaction after dripping, putting the product into a washing kettle for water washing, putting an upper oil layer into a desolventizing process, and performing decontamination water treatment on a water layer to obtain a dimethachlor toluene solution;

step S4: and (4) allowing the washed dimethachlor toluene solution obtained in the step (S3) to enter a lifting membrane for desolventizing, and removing the solvent for reuse, thereby finally obtaining the dimethachlor crude oil.

Preferably, the reaction kettle is a 500-liter stainless steel high-pressure reaction kettle, and the raw materials used in the N-alkylation reaction process are respectively 3kmol of 2, 6-dimethylaniline, 1kmol of chloroethyl methyl ether and 1kmol of 40% sodium hydroxide aqueous solution.

Preferably, the nitrogen in the reaction kettle is replaced for three times, the temperature of the heat conducting oil is 170 ℃, and the reaction time is 6 hours.

Preferably, when the reaction kettle is kept still for layering, the oil phase is washed by water and then rectified to obtain the amine ether intermediate, the content is more than or equal to 98 percent, and the yield is 86 percent.

Preferably, after the solvent toluene is added into the reaction kettle, the pH of the system is adjusted to 6-7 by liquid alkali, the temperature is controlled to 20-25 ℃, and then metered chloroacetyl chloride is slowly dropped.

Preferably, the reaction is incubated for 1 hour after the chloroacetyl chloride is added dropwise.

The novel process for synthesizing the dimethachlor has the beneficial effects that:

(1) sequentially adding 3kmol of 2, 6-dimethylaniline, 1kmol of chloroethyl methyl ether and 1kmol of 40% sodium hydroxide aqueous solution into a 500L stainless steel high-pressure reaction kettle, replacing three times by nitrogen, heating to react for six hours at 170 ℃, cooling and discharging after the reaction is finished, standing for layering, washing an oil phase by water, and rectifying to obtain an amine ether intermediate;

(2) qualified amine ether is metered and then put into an acylation kettle, and then solvent toluene is put into the acylation kettle. Regulating the pH of the system to 6-7 by using liquid alkali, controlling the temperature to be 20-25 ℃, slowly dripping metered chloroacetyl chloride, carrying out heat preservation reaction for one hour after dripping, then putting the mixture into a washing kettle, adding water for washing, carrying out desolventizing process on an upper oil layer, and carrying out sewage treatment on a water layer;

(3) the washed dimethachlor toluene solution enters a lifting membrane for desolventizing, and the desolventized solution is reused, so that the dimethachlor crude oil is finally obtained;

the synthetic process of the alachlor designed by the invention can improve the production efficiency, reduce the production cost, improve the production environment and obviously improve the yield of the alachlor.

Detailed Description

The present invention will be further illustrated with reference to the following specific examples.