阅读说明：本技术 一种二氯乙酰二烷基胺的合成工艺 (Synthesis process of dichloroacetyldialkylamine ) 是由 刘凯 杨露 刘虎 李舟 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种二氯乙酰二烷基胺的合成工艺,包括以下步骤：在干燥的反应容器内加入二烷基胺、有机溶剂和体积浓度为10～40%碱液,滴加二氯乙酰氯,所述二烷基胺、有机溶剂、碱液和二氯乙酰氯的摩尔比为1.0～1.2：2.0～7.2：1.0～1.5：1.0～1.2；滴加完毕后保温搅拌,得到混合液A；将混合液A抽滤分层,有机相减压脱溶浓缩,得到二氯乙酰二烷基胺。本发明以液碱替代二烷基胺作为缚酸剂,在保证二氯乙酰二烷基胺收率的同时,酰胺化反应中将二烷基胺的用量降低至1.0当量,合成工艺不仅显著减少了二烷基胺投料量、降低生产成本、避免大量二烷基铵盐酸盐的产生,而且反应体系还对水兼容,对于含水二烷基胺则不再需要额外除水,大大简化了工艺操作流程。(The invention discloses a synthesis process of dichloroacetyl dialkyl amine, which comprises the following steps: adding dialkyl amine, an organic solvent and 10-40% of alkali liquor by volume concentration into a dry reaction container, and dropwise adding dichloroacetyl chloride, wherein the molar ratio of the dialkyl amine to the organic solvent to the alkali liquor to the dichloroacetyl chloride is 1.0-1.2: 2.0-7.2: 1.0-1.5: 1.0 to 1.2; after the dropwise adding, stirring at a constant temperature to obtain a mixed solution A; and (3) carrying out suction filtration and layering on the mixed solution A, and carrying out decompression, dissolution and concentration on the organic phase under reduced pressure to obtain the dichloroacetyl dialkyl amine. The method uses liquid alkali to replace dialkylamine as an acid-binding agent, ensures the yield of the dichloroacetyl dialkylamine, reduces the dosage of the dialkylamine to 1.0 equivalent in amidation reaction, obviously reduces the dosage of the dialkylamine, reduces the production cost, avoids the generation of a large amount of dialkyl ammonium hydrochloride, ensures that a reaction system is compatible with water, does not need additional water removal for the water-containing dialkylamine, and greatly simplifies the process operation flow.)

1. A synthesis process of dichloroacetyl dialkyl amine is characterized by comprising the following steps:

step (1): adding dialkyl amine, an organic solvent and 10-40% of alkali liquor by volume concentration into a dry reaction container, and dropwise adding dichloroacetyl chloride, wherein the molar ratio of the dialkyl amine to the organic solvent to the alkali liquor to the dichloroacetyl chloride is 1.0-1.2: 2.0-7.2: 1.0-1: 5: 1.0 to 1.2;

step (2): after the dropwise adding, stirring at a constant temperature to obtain a mixed solution A;

and (3): and (3) carrying out suction filtration and layering on the mixed solution A, and carrying out decompression, dissolution and concentration on the organic phase under reduced pressure to obtain the dichloroacetyl dialkyl amine.

2. The process of claim 1 for the synthesis of dichloroacetoacetdialkylamine, wherein: the dialkyl amine is N-methyl methylamine or N-ethyl ethylamine or diisopropylamine.

3. The process of claim 1 for the synthesis of dichloroacetoacetdialkylamine, wherein: the organic solvent adopts toluene or dichloroethane or methyl tert-butyl ether or n-heptane or n-butyl ether.

4. The process of claim 1 for the synthesis of dichloroacetoacetdialkylamine, wherein: the alkali liquor is sodium hydroxide solution or potassium hydroxide solution or sodium carbonate solution.

5. The process of claim 1 for the synthesis of dichloroacetoacetdialkylamine, wherein: slowly dripping during the dripping in the step (1) to keep the temperature in the reaction container within 0-30 ℃.

6. The process according to claim 5, wherein the synthesis of dichloroacetoacetdialkylamine comprises: the stirring speed in the step (2) is 100-400 r/min, and the stirring time is 10-30 min.

7. The process of claim 6 for the synthesis of dichloroacetoacetdialkylamine, wherein: in the step (3), the negative pressure is 0.092MPa and the temperature is 50 ℃ during the vacuum desolventizing concentration.

Technical Field

The invention relates to the technical field of fine chemical engineering, in particular to a synthesis process of dichloroacetyl dialkyl amine.

Background

Dichloroacetyl dialkyl amine is an important fine chemical intermediate, and can be further derivatized to prepare difluoroacetic acid and ethyl difluoroacetate. In literature reports, the amidation reaction is usually carried out using dialkylamine as both a raw material and an acid-binding agent, for example, patent: CN102875379, JPH06228043, CN 104072357. In order to ensure the yield of amidation, it is necessary to have more than 2.0 equivalents of dialkylamine to participate in the reaction, and then a large amount of dialkyl ammonium hydrochloride is obtained. Because the cost of the dialkyl amine is high, the dialkyl amine needs to be dissociated by liquid alkali for recycling, and the recycled dialkyl amine needs to be further subjected to treatments such as dewatering and drying to meet the application requirement. Therefore, the development of a process with economic raw material consumption and convenient operation for synthesizing dichloroacetyl dialkyl amine has important significance.

Generally speaking, acyl chloride compounds are relatively active and can be decomposed when meeting water, so in order to avoid acyl chloride decomposition in the amidation process, the amidation reactions in the patents are all anhydrous systems, and the systems are ensured to be isolated from water by measures such as a sealed system with a buffer and the like. However, hydrolysis of acid chlorides competes with amidation, and amidation is easier to perform than hydrolysis. The inventor finds that the hydrolysis reaction can be effectively inhibited by adjusting conditions such as feeding modes, reaction temperature and the like in the experimental process. Therefore, in the experimental process, dichloroacetyl chloride is slowly dripped into the liquid alkali solution of the dialkylamine at a low temperature, and the dichloroacetyl dialkylamine is obtained with higher yield; further, by adjusting the reaction ratio, the charge ratio of the dialkylamine in the amidation reaction can be reduced to 1.0 equivalent while ensuring high yield. The synthesis of dichloroacetyldialkylamine by the above method is not known at present, which is referred to as a patent.

Disclosure of Invention

In order to solve the technical problems, the invention provides a synthesis process of dichloroacetyl dialkylamine, liquid alkali is used for replacing dialkylamine as an acid-binding agent, the yield of the dichloroacetyl dialkylamine is ensured, simultaneously, the dosage of the dialkylamine in amidation reaction is reduced to 1.0 equivalent, the synthesis process not only obviously reduces the dosage of the dialkylamine, reduces the production cost and avoids the generation of a large amount of dialkyl ammonium hydrochloride, but also ensures that a reaction system is compatible with water, no additional water removal is needed for the water-containing dialkylamine, and the process operation flow is greatly simplified.

The purpose of the invention is realized by the following technical scheme:

a synthesis process of dichloroacetyl dialkyl amine is characterized by comprising the following steps:

step (1): adding dialkyl amine, an organic solvent and 10-40% of alkali liquor by volume concentration into a dry reaction container, and dropwise adding dichloroacetyl chloride, wherein the molar ratio of the dialkyl amine to the organic solvent to the alkali liquor to the dichloroacetyl chloride is 1.0-1.2: 2.0-7.2: 1.0-1: 5: 1.0 to 1.2;

step (2): after the dropwise adding, stirring at a constant temperature to obtain a mixed solution A;

and (3): and (3) carrying out suction filtration and layering on the mixed solution A, and carrying out decompression, dissolution and concentration on the organic phase under reduced pressure to obtain the dichloroacetyl dialkyl amine.

Preferably, the dialkylamine is N-methyl methylamine or N-ethyl ethylamine or diisopropylamine.

Preferably, the organic solvent is toluene or dichloroethane or methyl tert-butyl ether or n-heptane or n-butyl ether.

Preferably, the alkali liquor is sodium hydroxide solution or potassium hydroxide solution or sodium carbonate solution.

Preferably, the dropwise addition in the step (1) is performed slowly so that the temperature in the reaction vessel is maintained within 0 to 30 ℃.

Preferably, the stirring speed in the step (2) is 100-400 r/min, and the stirring time is 10-30 min.

Preferably, in the step (3), the negative pressure is 0.092MPa and the temperature is 50 ℃ when the vacuum desolventizing concentration is carried out.

The invention has the advantages that:

the invention provides a synthesis process of dichloroacetyl dialkylamine, wherein liquid alkali is used for replacing dialkylamine as an acid-binding agent, the yield of dichloroacetyl dialkylamine is ensured, and the dosage of the dialkylamine in amidation reaction is reduced to 1.0 equivalent.

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.

Example 1

1.5mol of N-methyl methylamine, 3.0mol of toluene and 1.5mol of 10 percent sodium hydroxide solution are added into a 2000ml dry flask, 1.5mol of dichloroacetyl chloride is dripped at the temperature of 0-10 ℃, the temperature is kept and the stirring is carried out for 20min after the dripping is finished, and the stirring speed is 100 r/min. And (3) carrying out suction filtration and layering, carrying out vacuum desolventizing and concentrating on the organic phase, wherein the vacuum pressure is 0.092MPa and the temperature is 50 ℃ during vacuum desolventizing and concentrating, and obtaining 1.37mol of N, N-dimethyldichloroacetamide.

Example 2

Adding 0.5mol of N-ethyl ethylamine, 2mol of dichloroethane and 0.6mol of 20% potassium hydroxide solution into a 1000ml dry flask, dropwise adding 0.5mol of dichloroacetyl chloride at 10-20 ℃, preserving heat and stirring for 10min after the dropwise adding is finished, wherein the stirring speed is 200 r/min. And (3) carrying out suction filtration and layering, carrying out vacuum desolventizing and concentrating on the organic phase, wherein the vacuum pressure is 0.092MPa and the temperature is 50 ℃ during vacuum desolventizing and concentrating, and obtaining 0.48mol of N, N-diethyl dichloroacetamide.

Example 3

Adding 0.55mol of N-ethyl ethylamine, 3mol of methyl tert-butyl ether and 0.75mol of 30% sodium carbonate solution into a 1000ml dry flask, dropwise adding 0.55mol of dichloroacetyl chloride at 20-30 ℃, preserving heat and stirring for 30min after the dropwise adding is finished, wherein the stirring speed is 400 r/min. Filtering, layering, decompressing, desolventizing and concentrating the organic phase, wherein the negative pressure is 0.092MPa and the temperature is 50 ℃ during decompressing, desolventizing and concentrating to obtain 0.528mol of 0.48N, N-diethyl dichloroacetamide.

Example 4

1.89mol of diisopropylamine, 6.3mol of n-heptane and 2.04mol of 40% sodium hydroxide solution are added into a 2000ml dry flask, 1.89mol of dichloroacetyl chloride is dripped at the temperature of 10-20 ℃, the mixture is stirred for 20min under the condition of heat preservation after the dripping is finished, and the stirring speed is 300 r/min. And (3) carrying out suction filtration and layering, carrying out vacuum desolventizing and concentrating on the organic phase, wherein the vacuum pressure is 0.092MPa and the temperature is 50 ℃ during vacuum desolventizing and concentrating, and obtaining 1.57mol of N, N-diisopropyl dichloroacetamide.

Example 5

1.0mol of diisopropylamine, 4.03mol of n-butyl ether and 1.3mol of 40% sodium hydroxide solution are added into a 2000ml dry flask, 1.5mol of dichloroacetyl chloride is dripped at the temperature of 10-20 ℃, the mixture is stirred for 20min under the condition of heat preservation after the dripping is finished, and the stirring speed is 50 r/min. And (3) carrying out suction filtration and layering, carrying out vacuum desolventizing and concentrating on the organic phase, wherein the vacuum pressure is 0.092MPa and the temperature is 50 ℃ during vacuum desolventizing and concentrating, and obtaining 1.32mol of N, N-diisopropyl dichloroacetamide.

Example 6

1.5mol of N-methyl methylamine, 4.0mol of toluene and 1.3mol of 10 percent sodium hydroxide solution are added into a 2000ml dry flask, 1.0mol of dichloroacetyl chloride is dripped at the temperature of 0-10 ℃, the temperature is kept and the stirring is carried out for 20min after the dripping is finished, and the stirring speed is 500 r/min. And (3) carrying out suction filtration and layering, carrying out vacuum desolventizing and concentrating on the organic phase, wherein the vacuum pressure is 0.092MPa and the temperature is 50 ℃ during vacuum desolventizing and concentrating, and obtaining 0.86mol of N, N-dimethyldichloroacetamide.

The products obtained in examples 1 to 6 were tested, and the test items and methods were as follows: the product dichloroacetyl dialkyl amine is measured by gas chromatography, the gas phase peak area is the purity of the product dichloroacetyl dialkyl amine, and the yield is calculated by utilizing the purity.

The test results are shown in table 1:

TABLE 1 product test results

Test items	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6
							Purity (%)	96.80	99.43	98.17	92.77	92.33	96.14
Yield (%)	91.33	95.16	96.08	83.22	84.16	91.17

As can be seen from the table above, among several kinds of dialkylamines, when N-ethyl ethylamine is used as a reactant, the yield is high and is more than 95%; other dialkylamines are not in high yield. According to the market price, the diethylamine is 16000 yuan/ton, 32% liquid alkali is 600 yuan/ton, the invention uses the liquid alkali to replace the dialkylamine as the acid-binding agent, so that the dosage of the diethylamine is reduced, and the production cost can be greatly reduced.

In summary, after reading the present disclosure, those skilled in the art should make various other modifications without creative efforts according to the technical solutions and concepts of the present disclosure, which are within the protection scope of the present disclosure.