阅读说明：本技术 一种制备2-氯乙胺盐酸盐的方法 (Method for preparing 2-chloroethylamine hydrochloride ) 是由 林峰 于 2020-04-17 设计创作，主要内容包括：本发明涉及精细化工技术领域,针对现有技术2-氯乙胺盐酸盐的合成过程能耗较高的问题,公开了一种制备2-氯乙胺盐酸盐的方法,所述2-氯乙胺盐酸盐的制备过程包括如下步骤：(1)合成2-氯乙胺盐酸盐：室温下,在容器中投入无水乙醇胺和甲苯,搅拌升温反应,然后滴加三氯化磷,升温反应；(2)分离：反应完毕后,降温静置,抽取下层粘稠物亚磷酸并过滤,得到上层混合物,再真空干燥得到灰色固体；(3)重结晶：将上述灰色固体加入戊醇重结晶,过滤,60-65℃干燥,得成品。本发明采用了三氯化磷作为氯化试剂,过程中不存在水参与过程,没有废水需要蒸除,降低工艺的能耗；三氯化磷的副产物为亚磷酸,是可以二次回收利用的原料。(The invention relates to the technical field of fine chemical engineering, and discloses a method for preparing 2-chloroethylamine hydrochloride aiming at the problem of higher energy consumption in the synthesis process of 2-chloroethylamine hydrochloride in the prior art, wherein the preparation process of the 2-chloroethylamine hydrochloride comprises the following steps: (1) synthesis of 2-chloroethylamine hydrochloride: at room temperature, adding anhydrous ethanolamine and toluene into a container, stirring and heating for reaction, then dropwise adding phosphorus trichloride, and heating for reaction; (2) separation: after the reaction is finished, cooling and standing, extracting phosphorous acid of a lower-layer sticky matter and filtering to obtain an upper-layer mixture, and then carrying out vacuum drying to obtain a gray solid; (3) and (3) recrystallization: adding pentanol into the gray solid for recrystallization, filtering, and drying at 60-65 ℃ to obtain a finished product. The invention adopts phosphorus trichloride as a chlorination reagent, no water participation process exists in the process, no waste water needs to be distilled, and the energy consumption of the process is reduced; the byproduct of phosphorus trichloride is phosphorous acid which is a raw material capable of being recycled for secondary use.)

1. The method for preparing 2-chloroethylamine hydrochloride is characterized in that the synthetic route of the 2-chloroethylamine hydrochloride is as follows:

2. the method for preparing 2-chloroethylamine hydrochloride according to claim 1, wherein the preparation process of the 2-chloroethylamine hydrochloride comprises the following steps:

(1) synthesis of 2-chloroethylamine hydrochloride: at room temperature, adding anhydrous ethanolamine and toluene into a container, mechanically stirring for heating reaction, then dropwise adding phosphorus trichloride, heating reaction after dropwise adding, and performing QC tracking reaction;

(2) separation: after the reaction is finished, cooling and standing, extracting phosphorous acid of a lower-layer sticky matter and filtering to obtain an upper-layer mixture, and then carrying out vacuum drying to obtain a gray solid;

(3) and (3) recrystallization: adding pentanol into the gray solid for recrystallization, filtering, and drying at 60-65 ℃ to obtain the finished product.

3. The method for preparing 2-chloroethylamine hydrochloride according to claim 2, wherein the mass of phosphorus trichloride added in the step (1) is 0.6 to 1.2 times the mass of the anhydrous ethanolamine.

4. The method for preparing 2-chloroethylamine hydrochloride according to claim 2, wherein the mass ratio of the anhydrous ethanolamine to the toluene added in the step (1) is 1: 3-4.

5. The method for preparing 2-chloroethylamine hydrochloride according to claim 2, wherein the temperature rise rate in the step (1) is 1-4 ℃/min, the final temperature rise is 50-60 ℃, and the reaction time is 2.8-3.2 h.

6. The method for preparing 2-chloroethylamine hydrochloride according to claim 2, wherein the temperature in the step (2) is reduced to 38-42 ℃, and the standing time is 3.5-4 h.

7. The method for preparing 2-chloroethylamine hydrochloride according to claim 2, characterized in that the mass ratio of pentanol to gray solid added in step (3) is 3.2-3.5: 1.

8. the method for preparing 2-chloroethylamine hydrochloride according to claim 2, wherein the recrystallization in the step (3) is carried out by the following specific process: and refluxing and dissolving amyl alcohol and gray solid, naturally cooling to room temperature after 1-1.2h, continuously cooling to 4-6 ℃, and stirring for 30-35 min.

Technical Field

The invention relates to the technical field of fine chemical engineering, in particular to a method for preparing 2-chloroethylamine hydrochloride.

Background

The chloroethylamine hydrochloride is an important fine chemical product intermediate and is mainly applied to the industries of medicines, pesticides, surfactants, dyes and the like. In the field of high-tech materials, the method is mainly used for synthesizing aziridine cross-linking agent which acts with aqueous high polymer resin to form a surface coating; in 2016, 25 months 7, the European Cluster of catalysis research (European Cluster on catalysis) published the "European Circuit of catalysis science and technology" map, one of which is: catalysis improves sustainability of chemical processes, and relates to a novel monomer and a polymerization technique of unconventional monomers (such as epoxy compounds and aziridine), namely aziridine can also be used as a novel polymer synthetic monomer; the method can be used for synthesizing cefotiam and taurine in the pharmaceutical industry, and the Shandong platinum source pharmaceutical industry Co Ltd provides that the chloramine hydrochloride reacts with sodium methyl mercaptide to obtain an intermediate for lapatinib, namely treating late-stage or metastatic breast cancer, and the chloramine hydrochloride can also be used as a derivative reagent of amino acid, biuret and nucleotide in 2017. The prior synthesis method of the chloramine hydrochloride comprises the following steps: the hydroxyethylamine is chlorinated in the presence of concentrated hydrochloric acid or thionyl chloride, and then the excess hydrochloric acid or thionyl chloride is removed by distillation under reduced pressure.

Hydrochloric acid is used as a chlorination reagent, so that the requirement on a reaction kettle for industrial production is high, and excessive energy consumption is used for evaporating water in the post-treatment; the thionyl chloride is used as a chlorinating agent, redundant hydrogen chloride gas and sulfur dioxide gas are generated, the hydrogen chloride gas can reach 99% in a secondary alkali liquid absorption tower under the general condition, but the absorption rate of the sulfur dioxide is only 90%, so the process preferably reduces the generation of the sulfur dioxide as much as possible, and the investment pressure of environment-friendly equipment is reduced.

The patent No. CN201711482853.3 discloses a preparation method of 2-chloroethylamine hydrochloride, which specifically comprises the steps of taking ethanolamine as a raw material, taking organic acid as a catalyst, and taking hydrogen chloride as a chlorination reagent to carry out substitution reaction to prepare the 2-chloroethylamine hydrochloride. The method has the advantages of easily available raw materials, quick reaction, high product yield and high product purity; the byproduct hydrogen chloride is used as a chlorinated reagent to replace thionyl chloride, so that the generation of polluting gases is avoided, and the environmental pollution is greatly reduced.

The method has the disadvantages that hydrochloric acid is adopted as a chlorination reagent, the requirement on a reaction kettle for industrial production is high, and excessive energy consumption is required for evaporating water in the post-treatment.

Disclosure of Invention

The invention provides a method for preparing 2-chloroethylamine hydrochloride, aiming at overcoming the problem of higher energy consumption in the synthesis process of 2-chloroethylamine hydrochloride in the prior art, and the invention adopts phosphorus trichloride as a chlorination reagent, so that no water participation process exists in the process, no waste water needs to be distilled off, and the energy consumption of the process is reduced; the by-product of phosphorus trichloride is phosphorous acid, and is a raw material that can be recycled for the second time, does not have a large amount of solid wastes, and phosphorous acid can be sold and then reduce raw material cost simultaneously, so relative to other synthesis processes, phosphorus trichloride is more economic environmental protection for chlorination reagent.

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

a method for preparing 2-chloroethylamine hydrochloride, wherein the synthetic route of the 2-chloroethylamine hydrochloride is as follows:

preferably, the preparation process of the 2-chloroethylamine hydrochloride comprises the following steps:

(1) synthesis of 2-chloroethylamine hydrochloride: at room temperature, adding anhydrous ethanolamine and toluene into a container, mechanically stirring for heating reaction, then dropwise adding phosphorus trichloride, heating reaction after dropwise adding is finished, and performing QC (quality control) tracking reaction;

(2) separation: after the reaction is finished, cooling and standing, extracting phosphorous acid of a lower-layer sticky matter and filtering to obtain an upper-layer mixture, and then carrying out vacuum drying to obtain a gray solid;

(3) and (3) recrystallization: adding pentanol into the gray solid for recrystallization, filtering, and drying at 60-65 ℃ to obtain the finished product.

In the synthetic process, anhydrous ethanolamine is dissolved in toluene to serve as an initial raw material, phosphorus trichloride serves as a chlorination reagent, the reaction is carried out under the heating condition to generate chloroethylamine hydrochloride, then the reaction product is cooled, stood, separated, vacuum-dried to remove redundant hydrogen chloride gas, pentanol is added for recrystallization, and redundant impurities are removed, so that the high-purity 2-chloroethylamine hydrochloride product is obtained.

Preferably, the mass of the phosphorus trichloride added in the step (1) is 0.6 to 1.2 times of the mass of the anhydrous ethanolamine.

If too much phosphorus trichloride is added, excessive phosphorus trichloride is easy to cause unreacted phosphorus trichloride, additional distillation is needed for removal, the process steps are complicated, and if too little phosphorus trichloride is added, the reaction of the substrate anhydrous ethanolamine is incomplete, so that the yield of the final 2-chloroethylamine hydrochloride is reduced.

Preferably, the mass ratio of the anhydrous ethanolamine to the toluene added in the step (1) is 1: 3-4.

The toluene mainly plays a role of a solvent, and if the amount of the added toluene is too small, the dispersion effect is too poor, so that the reaction speed is reduced, the reaction is insufficient, and the reaction cannot be carried out in time; if the addition amount of the toluene is too much, the solvent cost is too high, raw material waste is caused, and the addition amount of the solvent only in the range of the invention can ensure that the anhydrous ethanolamine as the reaction substrate has better dispersion uniformity, so that the reaction can be timely and effectively carried out.

Preferably, the temperature rising rate in the step (1) is 1-2 ℃/min, the final temperature rising temperature is 50-60 ℃, and the reaction time is 2.8-3.2 h.

The temperature is increased to increase the activity of reactants, the reaction time is prolonged to ensure that the chlorination reaction is more sufficient, no waste of reaction materials is caused, and a high-quality target product is obtained.

Preferably, the temperature in the step (2) is reduced to 38-42 ℃, and the standing time is 3.5-4 h.

If the standing temperature is too high, partial products are easily wrapped by phosphorous acid, so that the purity of the products is reduced, an impurity removal treatment step is additionally added for removing the phosphorous acid on the surface, and meanwhile, the recycling efficiency of the phosphorous acid is reduced, and unnecessary waste is caused; if the temperature of stewing is too low, can lead to the viscosity increase of phosphorous acid, the mobility of phosphorous acid is relatively poor, and whole layering effect is poor, leads to the difficult extraction of phosphorous acid.

Preferably, the mass ratio of pentanol added in step (3) to gray solid is 3.2-3.5: 1.

preferably, the specific process of recrystallization in step (3) is: and refluxing and dissolving amyl alcohol and gray solid, naturally cooling to room temperature after 1-1.2h, separating out partial crystals, continuously cooling to 4-6 ℃, and stirring for 30-35 min.

If the addition of pentanol is too low, this will result in the grey solid becoming less soluble, resulting in a reduction in the purity of the final product; too much addition of pentanol reduces the crystallization rate of the final product, resulting in a lower final yield. The step-by-step cooling is to make the crystal precipitation easier, if the cooling speed is too fast, the temperature is directly cooled to 4-6 ℃ to easily precipitate oily substances rather than solid products, a part of crystals are precipitated at room temperature, and the temperature is continuously cooled to make the rest products continuously precipitated, so that the step-by-step precipitation of the products is ensured, and the performance and quality of the final products are optimized.

Therefore, the invention has the following beneficial effects:

(1) the invention provides a method for preparing 2-chloroethylamine hydrochloride, which adopts phosphorus trichloride as a chlorination reagent, and has no water participation process and no waste water needing to be distilled off in the process, thereby reducing the energy consumption of the process;

(2) the byproduct of phosphorus trichloride is phosphorous acid which is a raw material capable of being recycled for the second time, namely, a large amount of solid waste is not generated, and meanwhile, phosphorous acid can be sold to further reduce the cost of the raw material, so that compared with other synthesis processes, phosphorus trichloride is more economic and environment-friendly as a chlorination reagent;

(3) the preparation process has low energy consumption, no repeated reflux process, simple synthesis process, high synthesis efficiency and high yield of the obtained product.

Detailed Description

The invention is further described with reference to specific embodiments.