A water-soluble capsaicinoid ionic liquid stimulant and preparation method thereof

Abstract

The present invention provides a water-soluble capsaicin ionic liquid stimulant and a preparation method thereof. An equimolar cation donor is added to a solution containing capsaicin to obtain a solution containing capsaicin ionic liquid; the solution containing capsaicin ionic liquid is rotary evaporated to obtain a water-soluble capsaicin ionic liquid stimulant. The present invention adopts ion salt formation technology, selects safe, environmentally friendly, and stimulating capsaicin substances and water-soluble cation donor substances as reaction raw materials, and prepares a water-soluble capsaicin ionic liquid stimulant. The stimulant can have the dual properties of capsaicin and cation donors, not only has strong stimulating properties, but also is easily soluble in water, has a high decomposition temperature, good flame retardancy, and a wider range of applications. It can be miscible with water in any proportion and can be loaded into various injectors and riot control ammunition.

Description

Technical Field

[0001] The invention belongs to the technical field of police anti-riot weapons, and particularly relates to a water-soluble capsaicinoid ionic liquid stimulant and a preparation method thereof. Background Art

[0002] Irritants, commonly known as tear gas, are riot control agents widely used at home and abroad and have become essential equipment for police in various countries. Their main feature is that they irritate people's eyes, nose, throat and skin, causing discomfort and thus temporarily losing their combat effectiveness. Irritants are currently widely used by police and peacekeeping departments in various countries to disperse people, seal off target areas, and maintain social order because they have strong irritating effects, symptoms appear and disappear quickly, are safe to use, can be dispersed in a variety of ways, are non-lethal, and do not cause permanent harm to people.

[0003] At present, the irritant-type anti-terrorism and riot control agents developed at home and abroad mainly include CS tear gas, OC tear gas, CS tear gas blast agent, etc. Among them, OC irritant (i.e. capsaicin irritant) has replaced traditional irritants due to its low effective irritation concentration, safe use, and environmental protection. It has been widely used in police riot control and has become a new family of riot control agents.

[0004] There are many methods for applying riot control agents at home and abroad, which can be summarized into combustion type, explosion type, aerosol type and spray type. Combustion type and explosion type riot control agents are widely used in riot control because of their high long-term storage stability, good filling performance and convenient carrying. However, the above two dispersion methods are thermal dispersion methods. During the high-temperature dispersion process, the functional material capsaicin will slowly decompose due to heat, resulting in a partial loss of combat effectiveness of the equipment. Aerosol type and spray type mainly use liquid dosage form irritants, and disperse the liquid irritants to the target area through high-pressure gas. This dispersion method does not have environmental damage factors such as high temperature, and the irritants can be released without loss, which significantly improves the utilization rate of the irritants. However, capsaicin irritants such as OC and PAVA have extremely poor solubility in water. When they are made into liquid dosage forms and dispersed by aerosol and spray types, a large amount of organic cosolvents and surfactants need to be added to increase solubility. The irritants produced have problems such as high production cost, poor environmental protection, and difficulty in post-effect environmental treatment. Therefore, from the perspective of improving equipment performance, it is necessary to develop a new type of environmentally friendly and economical liquid irritant suitable for aerosol and spray equipment. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The invention provides a water-soluble capsaicinoid ionic liquid stimulant and a preparation method thereof, so as to solve the technical problem of how to adapt to aerosol type and spray type equipment.

[0007] (II) Technical solution

[0008] In order to solve the above technical problems, the present invention proposes a method for preparing a water-soluble capsaicin ionic liquid stimulant. The preparation method comprises the following steps: adding an equimolar cation donor to a solution containing a capsaicin substance to obtain a solution containing a capsaicin ionic liquid; and rotary evaporating the solution containing the capsaicin ionic liquid to obtain a water-soluble capsaicin ionic liquid stimulant.

[0009] Furthermore, an equimolar cation donor is added to a solution containing capsaicin-like substances, and the mixture is reacted at 25 to 50° C. for 10 to 20 hours to obtain a solution containing capsaicin-like ionic liquid; the solution containing capsaicin-like ionic liquid is rotary evaporated at 50 to 70° C. for 3 to 8 hours to obtain a water-soluble capsaicin-like ionic liquid stimulant.

[0010] Furthermore, the capsaicinoid substance is at least one of synthetic capsaicin, natural capsaicin, dihydrocapsaicin or nordihydrocapsaicin.

[0011] Furthermore, the synthetic capsaicin is nonanoic acid vanillamide.

[0012] Furthermore, the natural capsaicin is N-vanillyl-8-methyl-6-nonenamide.

[0013] Furthermore, dihydrocapsaicin is N-vanillyl-8-methylnonanamide.

[0014] Furthermore, nordihydrocapsaicin is N-vanillyl-7-methyloctanamide.

[0015] Furthermore, the cation is at least one of a quaternary ammonium cation, an imidazole cation, a pyrrolidine cation, and a pyrrolidone cation.

[0016] In addition, the present invention also provides a water-soluble capsaicin-based ionic liquid stimulant, which is prepared by the above method.

[0017] Furthermore, the irritant is composed of a capsaicin anion having irritation and a cation soluble in water, and has the structural formula:

[0018]

[0019] The anion in the structural formula is a pungent capsaicinoid substance, and the cation in the structural formula is formed by a cation donor that is easily soluble in water.

[0020] (III) Beneficial effects

[0021] The present invention provides a water-soluble capsaicin ionic liquid stimulant and a preparation method thereof. An equimolar cation donor is added to a solution containing capsaicin to obtain a solution containing capsaicin ionic liquid; the solution containing capsaicin ionic liquid is rotary evaporated to obtain a water-soluble capsaicin ionic liquid stimulant. The present invention adopts ion salt formation technology, selects safe, environmentally friendly, and stimulating capsaicin substances and water-soluble cation donor substances as reaction raw materials, and prepares a water-soluble capsaicin ionic liquid stimulant. The stimulant can have the dual properties of capsaicin and cation donors, not only has strong stimulating properties, but also is easily soluble in water, has a high decomposition temperature, good flame retardancy, and a wider range of applications. It can be miscible with water in any proportion and can be loaded into various injectors and riot control ammunition.

[0022] The water-soluble capsaicin ionic liquid stimulant of the present invention has the following characteristics:

[0023] (1) Ionic liquid irritants have both the irritation properties of capsaicin and the water solubility of cationic donors, and can be miscible with water in any proportion. Therefore, when preparing water-based riot control agents, it is no longer necessary to add a large amount of organic solvents and surfactants, which can significantly improve the environmental protection and economic efficiency of liquid irritants;

[0024] (2) Ionic liquid irritants are liquid salt substances that have the characteristics of high decomposition temperature of salts and are non-flammable, so they are also suitable for explosive and other heat-dispersive ammunition;

[0025] (3) The synthesis method of ionic liquid stimulants is simple, the raw materials are all commercially available, and the product quality is guaranteed. DETAILED DESCRIPTION

[0026] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with embodiments.

[0027] Example 1

[0028] A choline-synthesized capsaicin ionic liquid stimulant is prepared by the following method: synthetic capsaicin (nonanoic acid vanillylamide) powder (29.34 g, 0.1 mol) is dissolved in anhydrous ethanol at room temperature, choline hydroxide (in the form of a 50% aqueous solution) in an amount equal to that of nonanoic acid vanillylamide is added to the system under vigorous stirring, the reaction is terminated after stirring at 25° C. for 20 hours, the solution after the reaction is rotary evaporated at 55° C. for 3 hours to remove the solvent ethanol and water, and the ionic liquid synthesis reaction is as follows:

[0029]

[0030] The prepared ionic liquid was dissolved in water and completely dissolved in water in a very short time, indicating that the synthesized capsaicin ionic liquid has excellent water solubility. The choline capsaicin ionic liquid prepared by the above operation was diluted to a concentration of 2wt% and 10wt% respectively and then loaded into the injector and sprayed at room temperature. Effect: The guinea pigs treated showed symptoms such as scratching their ears, tears, closing their eyes, sneezing, etc. The irritation level was not less than that of capsaicin of the same concentration, and the irritation effect was even better.

[0031] Example 2

[0032] An imidazole natural capsaicin ionic liquid stimulant is prepared by the following method: natural capsaicin (N-vanillyl-8-methyl-6-nonenamide) powder (30.54 g, 0.1 mol) is dissolved in anhydrous ethanol at room temperature, imidazole (in the form of aqueous solution) in an amount equimolar to natural capsaicin is added to the system under vigorous stirring, the reaction is terminated after stirring at 35°C for 10 hours, the solution after the reaction is rotary evaporated at 65°C for 3 hours to remove the solvent ethanol and water, and the ionic liquid synthesis reaction is:

[0033]

[0034] The prepared ionic liquid was dissolved in water and completely dissolved in water in a very short time, indicating that the synthesized capsaicin ionic liquid has excellent water solubility. The imidazole capsaicin ionic liquid prepared by the above operation was diluted to a concentration of 2wt% and 10wt% and then loaded into an injector and sprayed at room temperature. Effect: The guinea pigs treated all showed symptoms such as scratching their ears, tears, closing their eyes, sneezing, etc. The irritation level was not lower than that of capsaicin of the same concentration, and the irritation effect was even better.

[0035] Example 3

[0036] An α-pyrrolidone dihydrocapsaicin ionic liquid is prepared by the following method: dihydrocapsaicin (N-vanillyl-8-methylnonanamide) powder (30.74 g, 0.1 mol) is dissolved in anhydrous ethanol at room temperature, α-pyrrolidone (in the form of a 50% aqueous solution) in an amount equal to that of dihydrocapsaicin is added to the system under vigorous stirring, the reaction is terminated after stirring at 50° C. for 15 hours, and the solution after the reaction is rotary evaporated at 60° C. for 5 hours to remove the solvent ethanol and water. The ionic liquid synthesis reaction is:

[0037]

[0038] The prepared ionic liquid was dissolved in water and completely dissolved in water in a very short time, indicating that the synthesized capsaicin ionic liquid has excellent water solubility. The α-pyrrolidone dihydrocapsaicin ionic liquid prepared by the above operation was diluted to a concentration of 2wt% and 10wt% and then loaded into an injector for injection at room temperature. Effect: The guinea pigs treated all showed symptoms such as scratching their ears, tears, closing their eyes, and sneezing. The degree of stimulation was not less than that of capsaicin of the same concentration, and the stimulation effect was even better.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a water-soluble capsaicinoid ionic liquid stimulant, characterized in that: The preparation method comprises the following steps: adding an equimolar cation donor to a solution containing a capsaicin-like substance to obtain a solution containing a capsaicin-like ionic liquid; rotary evaporating the solution containing the capsaicin-like ionic liquid to obtain a water-soluble capsaicin-like ionic liquid stimulant; the capsaicin-like substance is at least one of synthetic capsaicin, natural capsaicin, dihydrocapsaicin or nordihydrocapsaicin; the synthetic capsaicin is nonanoic acid vanillamide, the natural capsaicin is N-vanillyl-8-methyl-6-nonenamide, the dihydrocapsaicin is N-vanillyl-8-methylnonanamide, and the nordihydrocapsaicin is N-vanillyl-7-methyloctanamide; and the cation is at least one of a quaternary ammonium cation, an imidazole cation, a pyrrolidine cation, and a pyrrolidone cation.

2. The method for preparing the water-soluble capsaicinoid ionic liquid stimulant according to claim 1, characterized in that: An equimolar cation donor is added to a solution containing capsaicinoid substances, and the mixture is reacted at 25-50° C. for 10-20 hours to obtain a solution containing capsaicinoid ionic liquid; the solution containing capsaicinoid ionic liquid is rotary evaporated at 50-70° C. for 3-8 hours to obtain a water-soluble capsaicinoid ionic liquid stimulant.

3. A water-soluble capsaicinoid ionic liquid stimulant, characterized in that: The stimulant is prepared by the method according to claim 1 or 2.

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