A kind of synthetic method of dichloropropyleneamine

Abstract

The invention provides a method for synthesizing dichloroallylamine, comprising: putting diallylamine, a solvent and pyridine into a reaction bottle, adding dichloroacetyl chloride into a constant pressure dropping funnel, and dropping dichloroacetyl chloride into the reaction bottle under normal pressure to form a reaction system; after the dropping of dichloroacetyl chloride is completed, the reaction system in the reaction bottle is fully reacted; after the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloroallylamine and a filtered precipitate, the precipitate is washed with an organic solvent to obtain an organic solution containing dichloroallylamine, the filtrate containing dichloroallylamine and the organic solution containing dichloroallylamine are combined into an organic phase and washed to neutrality, and the organic phase is desolvated to obtain the product dichloroallylamine. The synthesis method uses pyridine as an acid binding agent, which can reduce the occurrence of side reactions, and pyridine can generate a hydrochloride precipitate with the byproduct hydrogen chloride, which is easy to separate from the product dichloroallylamine, so that high-purity and high-yield dichloroallylamine can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, in particular to a method for synthesizing dichloroallylamine. Background Art

[0002] Dichloroallylamine is a special agent for preventing and killing grass weeds, which can improve the resistance of corn to thiocarbamate herbicides, and can also protect wheat, rice, etc. from the damage of herbicides such as chloranil and acetochlor. At present, the synthetic route of dichloroallylamine mainly uses diallylamine and dichloroacetyl chloride as raw materials for acylation reaction, and adopts different acid binding agents to improve the yield of dichloroallylamine. The chemical property of dichloroacetyl chloride is very active and unstable, and can react nucleophilically with nucleophilic substances (such as water, diallylamine). The acid binding agent used in the prior art includes liquid caustic soda, sodium bicarbonate, triethylamine and triallylamine. Among the above-mentioned acid binding agents, some have certain nucleophilicity themselves, can react nucleophilically with dichloroacetyl chloride, and some can react with acylation byproduct hydrogen chloride to generate nucleophilic substances. For example, liquid alkali contains a certain amount of water. Sodium bicarbonate can react with hydrogen chloride produced by acylation reaction to generate water, which reacts with dichloroacetyl chloride to generate dichloroacetic acid. The nitrogen atom in triethylamine adopts SP 3 Hybridization, while the ethyl group has a certain electron-donating ability, so that the lone pair of electrons on the nitrogen atom has a certain nucleophilicity, and can react nucleophilically with dichloroacetyl chloride to form a quaternary ammonium salt; triallylamine has the same nucleophilic property as triethylamine, and can react nucleophilically with dichloroacetyl chloride to produce a quaternary ammonium salt. Since the above-mentioned acid-binding agents themselves or the by-products produced by the acid-binding agents will react nucleophilically with dichloroacetyl chloride, there are conditions for competing with the acylation reaction, so it is impossible to obtain high-yield and high-purity dichloroallylamine.

[0003] In view of this, it is necessary to improve the synthesis method of dichloropropyleneamine in the prior art to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a method for synthesizing dichloropropyleneamine, so as to solve the problem that it is difficult to obtain dichloropropyleneamine with high purity and high yield in the prior art.

[0005] To achieve the above object, the present invention provides a method for synthesizing dichloropropyleneamine, comprising the following steps:

[0006] Step S1, diallylamine, a solvent and pyridine are put into a reaction bottle, dichloroacetyl chloride is added into a constant pressure dropping funnel, and dichloroacetyl chloride is added dropwise into the reaction bottle under normal pressure to form a reaction system;

[0007] Step S2: After the addition of dichloroacetyl chloride is completed, the reaction system in the reaction bottle is allowed to fully react;

[0008] Step S3: After the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloropropyleneamine and a filtered precipitate, the precipitate is washed with an organic solvent to obtain an organic solution containing dichloropropyleneamine, the filtrate containing dichloropropyleneamine and the organic solution containing dichloropropyleneamine are combined to form an organic phase, the organic phase is washed to neutrality, and the organic phase is desolventized to obtain the product dichloropropyleneamine.

[0009] As a further improvement of the present invention, the solvent in step S1 is dichloromethane.

[0010] As a further improvement of the present invention, the molar ratio of diallylamine, dichloroacetyl chloride and pyridine in step S1 is diallylamine: dichloroacetyl chloride: pyridine = 1: (0.95-1.1): 0.95.

[0011] As a further improvement of the present invention, the volume-to-weight ratio of dichloromethane to diallylamine in step S1 is 2.75.

[0012] As a further improvement of the present invention, the temperature in the reaction bottle before the dichloroacetyl chloride is added dropwise in step S1 is -5°C to -10°C.

[0013] As a further improvement of the present invention, the temperature in the reaction flask during the dropwise addition of dichloroacetyl chloride in step S1 is below 0°C.

[0014] As a further improvement of the present invention, after the dropwise addition of dichloroacetyl chloride in step S2 is completed, the temperature of the reaction system in the reaction bottle is controlled at 5°C to -5°C during the reaction process.

[0015] As a further improvement of the present invention, the organic solvent in step S3 is dichloromethane.

[0016] As a further improvement of the present invention, the organic phase washing process in step S3 is to wash the organic phase in sequence with deionized water, dilute hydrochloric acid, and deionized water until it is neutral.

[0017] As a further improvement of the present invention, the organic phase is desolventized by vacuum distillation in step S3.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] In the present application, pyridine is used as an acid-binding agent, and diallylamine and dichloroacetyl chloride undergo an acylation reaction to generate dichloroallylamine. No water is required during the acylation reaction, and the product does not contain water. Therefore, dichloroacetyl chloride will not undergo a nucleophilic reaction with water and become inactivated. At the same time, the acid-binding agent used in the prior art itself or the by-products produced by the acid-binding agent will undergo a nucleophilic reaction with dichloroacetyl chloride, which has the conditions to compete with the acylation reaction, and the nitrogen atom of pyridine adopts SP 2 Hybridization, the lone pair of electrons on the nitrogen atom is conjugated with the aromatic ring, so that the nucleophilicity of the lone pair of electrons on the nitrogen atom of pyridine is weaker than the nucleophilicity of the lone pair of electrons on the nitrogen atom in diallylamine, and the nucleophilicity of diallylamine with dichloroacetyl chloride is greater than the nucleophilicity of pyridine with dichloroacetyl chloride. Therefore, pyridine is used as an acid-binding agent, which does not have the conditions to compete with the acylation reaction, and thus high-purity and high-yield dichloroallylamine can be obtained, and pyridine can react with the hydrogen chloride produced by the acylation reaction to form a hydrochloride precipitate of pyridine, which can not only make the acylation reaction occur in the direction of generating dichloroallylamine, but also the hydrochloride precipitate of pyridine generated by the side reaction can be easily separated from the product dichloroallylamine. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention provides a synthesis step of a method for synthesizing dichloropropyleneamine;

[0021] Figure 2 HPLC chromatogram of Example 1 of the present invention;

[0022] Figure 3 This is the HPLC chromatogram of Example 2 of the present invention;

[0023] Figure 4 The HPLC chromatogram of Example 3 of the present invention is shown in FIG. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0025] Please refer to Figures 1 to 4 A specific implementation method of the disclosed method for synthesizing dichloropropyleneamine.

[0026] In the embodiments of the present application, the unit "g" is the weight unit "gram"; "normal pressure" is 101Kpa; the unit "Kpa" is the pressure unit "kilopascal"; the unit "℃" is the temperature unit "degrees Celsius"; the unit "mL" is the volume unit "milliliter"; "min" is the time unit "minute"; and "nm" is the length unit "nanometer".

[0027] Please refer to Figure 1 As shown, Figure 1 The present invention provides a method for synthesizing dichloropropyleneamine, which comprises at least steps S1 to S3:

[0028] Step S1, diallylamine, a solvent and pyridine are put into a reaction bottle, dichloroacetyl chloride is added into a constant pressure dropping funnel, and dichloroacetyl chloride is added dropwise into the reaction bottle under normal pressure to form a reaction system;

[0029] Step S2: After the addition of dichloroacetyl chloride is completed, the reaction system in the reaction bottle is allowed to fully react;

[0030] Step S3: After the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloropropyleneamine and a filtered precipitate, the precipitate is washed with an organic solvent to obtain an organic solution containing dichloropropyleneamine, the filtrate containing dichloropropyleneamine and the organic solution containing dichloropropyleneamine are combined to form an organic phase, the organic phase is washed to neutrality, and the organic phase is desolventized to obtain the product dichloropropyleneamine.

[0031] It should be noted that in the present application, pyridine is used as an acid binding agent and dichloromethane is used as a solvent. The molar ratio of diallylamine, dichloroacetyl chloride and pyridine is diallylamine: dichloroacetyl chloride: pyridine = 1: (0.95-1.1): 0.95. And the volume-to-weight ratio of dichloromethane to diallylamine is 2.75. The temperature in the reaction bottle before the addition of dichloroacetyl chloride is -5°C to -10°C, the temperature in the reaction bottle during the addition of dichloroacetyl chloride is below 0°C, and after the addition of dichloroacetyl chloride in step S2 is completed, the temperature in the reaction bottle during the reaction of the reaction system in the reaction bottle is controlled to be 5°C to -5°C. The organic solvent in step S3 is dichloromethane. The organic phase washing process is to wash the organic phase to neutrality in the order of deionized water, dilute hydrochloric acid, and deionized water.

[0032] Specifically, first take a certain proportion of diallylamine, dichloromethane and pyridine and put them into the reaction bottle, and add dichloroacetyl chloride in the constant pressure dropping funnel. The molar ratio of diallylamine, dichloroacetyl chloride and pyridine is diallylamine: dichloroacetyl chloride: pyridine = 1: (0.95-1.1): 0.95, and the volume-weight ratio of dichloromethane to diallylamine is 2.75. When the temperature in the reaction bottle reaches -5°C to -10°C under normal pressure, dichloroacetyl chloride is slowly added dropwise to the reaction bottle to form a reaction system, and the temperature in the reaction bottle is below 0°C during the addition. After the addition of dichloroacetyl chloride is completed, the temperature in the reaction bottle is controlled to 5°C to -5°C, and the reaction is performed for 1 hour. After the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloroallylamine and a precipitate after filtration, and the precipitate is a hydrochloride of pyridine generated by the salt-forming reaction of hydrogen chloride generated by the acylation reaction and pyridine. Since the precipitate also contains some dichloropropeneamine, the precipitate is washed with dichloromethane to obtain a dichloropropeneamine-containing dichloropropeneamine solution, the filtrate containing dichloropropeneamine and the dichloropropeneamine-containing dichloropropeneamine solution are combined into an organic phase, the organic phase is washed with deionized water, dilute hydrochloric acid, and deionized water in sequence until neutral, the product dichloropropeneamine is obtained after the solvent is removed by reduced pressure distillation, and the purity of dichloropropeneamine is analyzed by high performance liquid chromatography (HPLC). The high performance liquid chromatograph model is Shimadzu LC-2030C Plus high performance liquid chromatograph, methanol is used as the mobile phase, the temperature is set to 25°C, the wavelength is 240nm, and the flow rate is 1.000mL / min.

[0033] In the present application, dichloroacetyl chloride and diallylamine undergo acylation reaction to generate dichloroallylamine and hydrogen chloride. The chemical properties of dichloroacetyl chloride are very active and unstable, and it is easy to react with nucleophilic substances.

[0034] In the prior art, commonly used liquid caustic soda, sodium bicarbonate, triethylamine and triallylamine are used as acid binding agents.

[0035] When liquid alkali is used as an acid-binding agent, water in the liquid alkali reacts with dichloroacetyl chloride to generate dichloroacetic acid, which inactivates the dichloroacetyl chloride. Therefore, it is difficult to obtain a high yield of dichloroallylamine in the acylation reaction using liquid alkali as an acid-binding agent.

[0036] When sodium bicarbonate is used as an acid binding agent, sodium bicarbonate is solid and diallylamine is liquid. The hydrogen chloride produced by the acylation reaction is more likely to react with the diallylamine in liquid form to form a salt, and the salified diallylamine cannot continue to react with dichloroacetyl chloride. Meanwhile, the hydrogen chloride produced by the acylation reaction reacts with sodium bicarbonate to produce water by acid-base neutralization reaction, and the generated water reacts with dichloroacetyl chloride to deactivate dichloroacetyl chloride by nucleophilic reaction. Therefore, the acylation reaction using sodium bicarbonate as an acid binding agent is difficult to obtain dichloroallylamine in high yield.

[0037] When triethylamine is used as an acid binding agent, the nitrogen atom in triethylamine is SP 3 Hybridization, and the ethyl group has a certain electron-donating ability, which makes the lone pair of electrons on the nitrogen atom in triethylamine have a certain nucleophilicity, and can react with dichloroacetyl chloride to form a quaternary ammonium salt. Therefore, it is difficult to obtain a high yield of dichloroallylamine using triethylamine as an acid-binding agent.

[0038] When triallylamine is used as an acid-binding agent, it is difficult to obtain dichloroallylamine in high yield because triallylamine has the same nucleophilic property as triethylamine and can react with dichloroacetyl chloride to produce quaternary ammonium salt. In addition, the price of triallylamine is relatively high, which increases the production cost.

[0039] In the present application, pyridine is used as an acid-binding agent, and diallylamine and dichloroacetyl chloride undergo an acylation reaction to generate dichloroallylamine. Water is not required during the acylation reaction, and the product does not contain water. Therefore, dichloroacetyl chloride will not undergo a nucleophilic reaction with water and become inactivated. 2 Hybridization, the lone pair of electrons on the nitrogen atom is conjugated with the aromatic ring, so that the nucleophilicity of the lone pair of electrons on the nitrogen atom is weaker than the nucleophilicity of the lone pair of electrons on the nitrogen atom in diallylamine, then the nucleophilicity of diallylamine with dichloroacetyl chloride is greater than the nucleophilicity of pyridine with dichloroacetyl chloride, and pyridine is difficult to react with dichloroacetyl chloride to form a quaternary ammonium salt, thereby avoiding the inactivation of dichloroacetyl chloride as a raw material and affecting the yield and quality of the product. Therefore, using pyridine as an acid binding agent can obtain dichloroallylamine with high purity and high yield. At the same time, the hydrogen chloride produced by the acylation reaction can react with pyridine to form a hydrochloride precipitate of pyridine, which not only avoids the salt reaction between diallylamine and hydrogen chloride and causes the termination of the acylation reaction, but also makes the acylation reaction occur in the direction of generating dichloroallylamine, and the hydrochloride precipitate of pyridine generated by the side reaction is also easy to separate from the product dichloroallylamine.

[0040] Embodiment 1:

[0041] Prepare the raw materials according to the molar ratio of diallylamine: dichloroacetyl chloride: pyridine = 1: 0.95: 0.95, put 14.56g of diallylamine, 40mL of dichloromethane and 11.3g of pyridine into the reaction bottle, add 21g of dichloroacetyl chloride to the constant pressure dropping funnel, wherein the volume-weight ratio of dichloromethane to diallylamine is 2.75. When the temperature in the reaction bottle reaches -5℃~-10℃ under normal pressure, dichloroacetyl chloride is slowly added dropwise to the reaction bottle, and the temperature in the reaction bottle is below 0℃ during the addition. After the addition of dichloroacetyl chloride is completed, the temperature in the reaction bottle is controlled to 5℃~-5℃, and the reaction is carried out for 1 hour. After the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloroallylamine and a filtered precipitate. The precipitate was washed with dichloromethane to obtain an organic solution containing dichloroallylamine. The filtrate containing dichloroallylamine and the organic solution containing dichloroallylamine were combined to form an organic phase. The organic phase was washed with ionized water, dilute hydrochloric acid, and deionized water in sequence until neutral. The organic phase was desolvated by reduced pressure distillation to obtain 24.72 g of dichloroallylamine. The molar yield of dichloroallylamine was 83.5%. Figure 2 As shown, the horizontal axis of the HPLC chromatogram represents time, the vertical axis represents the response value of the electrical signal, the value of the horizontal axis corresponding to the highest point of the peak is the retention time, the retention time corresponding to peak number 1 is 1.838min, the retention time corresponding to peak number 2 is 2.104min, the retention time corresponding to peak number 3 is 2.337min, and the retention time corresponding to peak number 4 is 2.685min. The retention time corresponding to peak number 1 is the retention time of dichloropropenylamine, so peak number 1 is dichloropropenylamine, and the area of ​​peak number 1 accounts for 98.875%, so the dichloropropenylamine in the organic phase in Example 1 accounts for 98.875%, and the HPLC purity of dichloropropenylamine is 98.875%. Peak numbers 2 to 4 are impurities in the organic phase, and the sum of the area of ​​peak numbers 2 to 4 is 1.125%, so the impurity proportion of the organic phase in Example 1 is 1.125%.

[0042] Embodiment 2:

[0043] Prepare the raw materials according to the molar ratio of diallylamine: dichloroacetyl chloride: pyridine = 1: 1.05: 0.95, put 29.12g of diallylamine, 80mL of dichloromethane and 22.6g of pyridine into the reaction bottle, add 46.4g of dichloroacetyl chloride to the constant pressure dropping funnel, wherein the volume-weight ratio of dichloromethane to diallylamine is 2.75. When the temperature in the reaction bottle reaches -5℃~-10℃ under normal pressure, dichloroacetyl chloride is slowly added dropwise to the reaction bottle, and the temperature in the reaction bottle is below 0℃ during the addition. After the addition of dichloroacetyl chloride is completed, the temperature in the reaction bottle is controlled to 5℃~-5℃, and the reaction is carried out for 1 hour. After the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloroallylamine and a filtered precipitate. The precipitate was washed with dichloromethane to obtain an organic solution containing dichloroallylamine. The filtrate containing dichloroallylamine and the organic solution containing dichloroallylamine were combined to form an organic phase. The organic phase was washed with deionized water, dilute hydrochloric acid, and deionized water in sequence until neutral. The organic phase was desolvated by reduced pressure distillation to obtain 61.44 g of dichloroallylamine. The molar yield of dichloroallylamine was 98.4%. Figure 3 As shown, the retention time corresponding to peak number 1 is 1.839min, the retention time corresponding to peak number 2 is 2.104min, the retention time corresponding to peak number 3 is 2.335min, and the retention time corresponding to peak number 4 is 2.687min. The retention time corresponding to peak number 1 is the retention time of dichloropropenylamine, so peak number 1 is dichloropropenylamine. The area ratio of peak number 1 is 98.938%, so the proportion of dichloropropenylamine in the organic phase in Example 2 is 98.938%, and the HPLC purity of dichloropropenylamine is 98.938%. Peak numbers 2 to 4 are impurities in the organic phase, and the sum of the area ratios of peak numbers 2 to 4 is 1.062%, so the proportion of impurities in the organic phase in Example 2 is 1.062%.

[0044] Embodiment three:

[0045] Prepare the raw materials according to the molar ratio of diallylamine: dichloroacetyl chloride: pyridine = 1: 1.1: 0.95, put 58.24g of diallylamine, 160mL of dichloromethane and 45.2g of pyridine into the reaction bottle, add 97.2g of dichloroacetyl chloride to the constant pressure dropping funnel, wherein the volume-weight ratio of dichloromethane to diallylamine is 2.75. When the temperature in the reaction bottle reaches -5℃~-10℃ under normal pressure, dichloroacetyl chloride is slowly added dropwise to the reaction bottle, and the temperature in the reaction bottle is below 0℃ during the addition. After the addition of dichloroacetyl chloride is completed, the temperature in the reaction bottle is controlled to 5℃~-5℃, and the reaction is carried out for 1 hour. After the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloroallylamine and a filtered precipitate. The precipitate was washed with dichloromethane to obtain an organic solution containing dichloropropyleneamine. The filtrate containing dichloropropyleneamine and the organic solution containing dichloropropyleneamine were combined to form an organic phase. The organic phase was washed with deionized water, dilute hydrochloric acid, and deionized water in sequence until neutral. After the organic phase was desolventized, 124.01 g of dichloropropyleneamine was obtained. Therefore, the molar yield of dichloropropyleneamine was 99.3%. Figure 4 As shown, the retention time corresponding to peak number 1 is 1.841min, the retention time corresponding to peak number 2 is 2.101min, the retention time corresponding to peak number 3 is 2.400min, the retention time corresponding to peak number 4 is 2.752min, and the retention time corresponding to peak number 5 is 3.650min. The retention time corresponding to peak number 1 is the retention time of dichloropropenylamine, so peak number 1 is dichloropropenylamine. The area ratio of peak number 1 is 99.512%, so the proportion of dichloropropenylamine in the organic phase in Example 3 is 99.512%, and the HPLC purity of dichloropropenylamine is 99.512%. Peak numbers 2 to 5 are impurities in the organic phase, and the sum of the area ratios of peak numbers 2 to 5 is 0.488%, so the proportion of impurities in the organic phase in Example 3 is 0.488%.

[0046] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0047] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for synthesizing dichloropropyleneamine, characterized in that: The following steps are involved: Step S1, diallylamine, a solvent and pyridine are put into a reaction bottle, dichloroacetyl chloride is added into a constant pressure dropping funnel, and dichloroacetyl chloride is added dropwise into the reaction bottle under normal pressure to form a reaction system; Step S2: After the addition of dichloroacetyl chloride is completed, the reaction system in the reaction bottle is allowed to fully react; Step S3: After the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloropropyleneamine and a filtered precipitate, the precipitate is washed with an organic solvent to obtain an organic solution containing dichloropropyleneamine, the filtrate containing dichloropropyleneamine and the organic solution containing dichloropropyleneamine are combined to form an organic phase, the organic phase is washed to neutrality, and the organic phase is desolventized to obtain the product dichloropropyleneamine.

2. The method for synthesizing dichloropropyleneamine according to claim 1, characterized in that: The solvent in step S1 is dichloromethane.

3. The method for synthesizing dichloropropyleneamine according to claim 2, characterized in that: In the step S1, the molar ratio of diallylamine, dichloroacetyl chloride and pyridine is diallylamine: dichloroacetyl chloride: pyridine = 1: (0.95-1.1): 0.

95.

4. The method for synthesizing dichloropropyleneamine according to claim 1, characterized in that: In the step S1, the temperature in the reaction bottle before the dichloroacetyl chloride is added dropwise is -5°C to -10°C.

5. The method for synthesizing dichloropropyleneamine according to claim 4, characterized in that: During the dropwise addition of dichloroacetyl chloride in step S1, the temperature in the reaction flask is below 0°C.

6. The method for synthesizing dichloropropyleneamine according to claim 5, characterized in that: After the dropwise addition of dichloroacetyl chloride in step S2 is completed, the temperature of the reaction system in the reaction bottle is controlled at 5° C. to -5° C. during the reaction process.

7. The method for synthesizing dichloropropyleneamine according to claim 1, characterized in that: The organic solvent in step S3 is dichloromethane.

8. The method for synthesizing dichloropropyleneamine according to claim 7, characterized in that: The organic phase washing process in step S3 is to wash the organic phase in sequence with deionized water, dilute hydrochloric acid, and deionized water until it is neutral.

9. The method for synthesizing dichloropropyleneamine according to claim 8, characterized in that: In step S3, the organic phase is desolventized by vacuum distillation.

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