Continuous flow synthesis method of triaminoguanidine hydrochloride

Abstract

The invention relates to a continuous flow synthesis method of triaminoguanidine hydrochloride, which comprises the following steps: adding a material A and a material B into a microchannel reactor, and reacting to obtain the triaminoguanidine hydrochloride, wherein the material A comprises guanidine hydrochloride and a solvent; the material B comprises hydrazine hydrate. The continuous flow synthesis method provided by the invention has the advantages of simplicity and convenience in operation, greenness, safety, stable yield, high product purity and the like, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a continuous flow synthesis method of triaminoguanidine hydrochloride. Background Art

[0002] Triaminoguanidine salt is an ionic compound. The triaminoguanidine cation forms a large π bond, and the molecular stability is improved. Such compounds generally have a high positive formation enthalpy, a high nitrogen content in the molecular structure, and a low carbon and hydrogen content, making it easier to achieve oxygen balance, and a large amount of gas released during combustion and explosion. Because triaminoguanidine hydrochloride has better thermal stability and mechanical properties than other triaminoguanidine salts, and shows good compatibility when mixed with other non-energetic components, it can better release energy. Therefore, the hydrochloride of triaminoguanidine has attracted much attention from scientific researchers in the synthesis of energetic materials, and is widely used in the research and preparation of energetic compounds such as high-energy propellants and pyrotechnic products.

[0003] At present, the synthesis method of triaminoguanidine hydrochloride has the problems of complicated operation, low safety, low overall yield, poor product purity, etc., which seriously limits the possibility of its practical application. At present, triaminoguanidine hydrochloride is generally prepared by heating guanidine hydrochloride and excess hydrazine hydrate in dioxane under reflux, and the yield can reach about 70%.

[0004] Therefore, it is of great significance to provide a continuous flow synthesis method of triaminoguanidine hydrochloride with high yield and high quality. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a continuous flow synthesis method of triaminoguanidine hydrochloride. Compared with the traditional reaction method, the method of the present invention is safe, reliable, efficient, stable in yield and has no amplification effect.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the continuous flow synthesis method comprising the following steps:

[0008] Adding material A and material B into a microchannel reactor to react to obtain the triaminoguanidine hydrochloride;

[0009] Wherein, the material A comprises guanidine hydrochloride and a solvent;

[0010] The material B comprises hydrazine hydrate.

[0011] The synthesis route of triaminoguanidine hydrochloride according to the present invention is as follows:

[0012]

[0013] In the continuous flow synthesis method of triaminoguanidine hydrochloride provided by the present invention, commercially available guanidine hydrochloride and hydrazine hydrate are used as raw materials, and the reaction is carried out in a microchannel reactor to prepare the triaminoguanidine hydrochloride, which is simple to operate and increases the convenience of production; at the same time, the reaction time is greatly shortened, thereby improving the production efficiency; in addition, the synthesis method has a stable yield without amplification effect, and reduces the cumulative amount of ammonia per unit time during production, thereby improving the safety of production and being suitable for large-scale industrial production.

[0014] Preferably, the material A is fed into the microchannel reactor via a liquid plunger pump.

[0015] Preferably, the feed flow rate of material A is 1-50 mL / min, for example, it can be 2 mL / min, 3.5 mL / min, 5 mL / min, 10 mL / min, 15 mL / min, 20 mL / min, 25 mL / min, 30 mL / min, 35 mL / min, 40 mL / min or 45 mL / min, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, and 3.5-40 mL / min is further preferred.

[0016] In the present invention, when the feed flow rate of material A is 3.5-40 mL / min, it reacts with material B of a specific material flow rate, and the obtained target product triaminoguanidine hydrochloride has an optimal yield. When the feed flow rate of material A is too low or too high, the molar ratio of the reaction of guanidine hydrochloride and hydrazine hydrate will be affected, thereby causing material A and material B to be unable to fully react in the reactor, thereby affecting the yield of the target product.

[0017] Preferably, the molar concentration of guanidine hydrochloride in the material A is 2.1-8 mol / L, for example, 2.5 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, 7 mol / L, 7.5 mol / L or 8 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, the solvent in the material A comprises hydrazine hydrate and / or an organic solvent.

[0019] In the present invention, when the solvent in material A is preferably hydrazine hydrate, the reaction can be completed without adding other organic solvents, which can not only reduce the environmental pollution caused by the use of a large amount of organic solvents, making the synthesis more green and safe, but also help to reduce production costs and further improve economic benefits. At the same time, using hydrazine hydrate instead of organic solvents as a solvent can further shorten the reaction time and improve the yield of the target product.

[0020] Preferably, the mass percentage concentration of the hydrazine hydrate is 75-85%, for example, it can be 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83% or 84%.

[0021] Preferably, the organic solvent comprises any one of 1,4-dioxane, N,N-dimethylacetamide (DMAC) or N,N-dimethylformamide (DMF) or a combination of at least two thereof.

[0022] Preferably, the material B is fed into the microchannel reactor through a liquid plunger pump.

[0023] Preferably, the feed flow rate of material B is 1-20 mL / min, for example, it can be 1 mL / min, 2 mL / min, 4 mL / min, 8 mL / min, 8.5 mL / min, 9 mL / min, 10 mL / min, 12 mL / min, 15 mL / min or 20 mL / min, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, and 1-10 mL / min is further preferred.

[0024] In the present invention, when the feed flow rate of material B is 1-10 mL / min, it reacts with material A of a specific material flow rate, and the obtained target product triaminoguanidine hydrochloride has an optimal yield. When the feed flow rate of material B is too low or too high, it will affect the molar ratio of the reaction of guanidine hydrochloride and hydrazine hydrate, thereby causing material A and material B to be unable to fully contact and react in the reactor, thereby affecting the yield of the target product.

[0025] Preferably, the molar ratio of the guanidine hydrochloride to the total amount of hydrazine hydrate in material A and material B is 1:(3-10), for example, it can be 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8, 1:4, 1:5, 1:7 or 1:9, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, and more preferably 1:(3.4-5).

[0026] In the present invention, when the molar ratio of guanidine hydrochloride to the total amount of hydrazine hydrate in material A and material B is 1:(3-10), the obtained target product triaminoguanidine hydrochloride has a good yield, and when the molar ratio of the two is 1:(3.4-5), the yield is optimal. When the molar ratio of the two is higher than 1:3.4, due to too little hydrazine hydrate, the raw material guanidine hydrochloride cannot completely undergo substitution reaction with the hydrazine group, resulting in failure to obtain a higher yield and causing waste of the raw material guanidine hydrochloride. When the molar ratio of the two is lower than 1:5, due to excessive use of hydrazine hydrate, the reaction cost is increased.

[0027] In the present invention, the molar ratio of guanidine hydrochloride to the total amount of hydrazine hydrate in material A and material B is 1:(3-10), which means: (1) when the solvent in material A is hydrazine hydrate and no other organic solvent is added, the molar ratio of guanidine hydrochloride to the total amount of hydrazine hydrate in material A and material B is 1:(3-10); or (2) when the solvent in material A is an organic solvent, material A does not contain hydrazine hydrate, and at this time, the molar ratio of guanidine hydrochloride to the total amount of hydrazine hydrate in material B is 1:(3-10).

[0028] Preferably, the gauge pressure in the microchannel reactor is set to 0.1-0.5 MPa, for example, it can be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa or 0.5 MPa.

[0029] Preferably, the residence time of the reaction is 1-30 min, for example, 2 min, 5 min, 10 min, 15 min, 20 min, 25 min or 30 min.

[0030] Preferably, the reaction temperature is 60-120°C, for example, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 100°C, 110°C or 115°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, and more preferably 90-120°C.

[0031] In the present invention, the preferred range of the reaction temperature is set to 90-120°C. When it is lower than 90°C, the system temperature is low, resulting in a slow reaction and poor reaction effect; when it is higher than 120°C, the actual reaction temperature cannot reach the set temperature, and thus the yield of the target product will not be significantly improved.

[0032] Preferably, the reaction further includes a post-treatment process after completion.

[0033] Preferably, the post-treatment process includes cooling the reaction solution to room temperature, filtering, washing and drying.

[0034] Preferably, the washing agent used in the washing includes any one of ethyl acetate, 1,4-dioxane, petroleum ether or dichloromethane, or a combination of at least two thereof.

[0035] Preferably, the drying includes any one of natural air drying, oven drying or infrared lamp drying.

[0036] Preferably, the continuous flow synthesis method of triaminoguanidine hydrochloride specifically comprises the following steps:

[0037] (1) guanidine hydrochloride and a solvent are uniformly mixed to prepare a guanidine hydrochloride solution with a volume molar concentration of 2.1-8 mol / L to obtain material A; hydrazine hydrate with a mass percentage concentration of 75-85% is used as material B;

[0038] (2) adding material A and material B into a microchannel reactor, reacting at a gauge pressure of 0.1-0.5 MPa and 60-120° C., with a reaction residence time of 1-30 min. After the reaction is completed, cooling the reaction solution to room temperature, filtering with suction, washing the filter cake with a detergent, and drying to obtain the triaminoguanidine hydrochloride;

[0039] The material A is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 1-50 mL / min;

[0040] The solvent in the material A includes hydrazine hydrate and / or an organic solvent, and the organic solvent includes any one or a combination of at least two of 1,4-dioxane, N,N-dimethylacetamide or N,N-dimethylformamide;

[0041] The material B is metered by a liquid flow meter and fed into the microchannel reactor at a feed rate of 1-20 mL / min;

[0042] The molar ratio of the guanidine hydrochloride to the total amount of hydrazine hydrate in material A and material B is 1:(3-10);

[0043] The washing agent used in the washing includes any one of ethyl acetate, 1,4-dioxane, petroleum ether or dichloromethane, or a combination of at least two thereof;

[0044] The drying includes any one of natural air drying, oven drying or infrared lamp drying.

[0045] In the present invention, the continuous flow synthesis method can achieve accurate control of the reaction conditions, improve the selectivity and purity of the product. At the same time, the continuous flow synthesis method allows the reactants to be fed at an appropriate rate, avoiding the violent reaction of large quantities of raw materials, thereby improving the safety of the production reaction. In addition, compared with the traditional method, the continuous flow synthesis method provided by the present invention is reacted under high temperature and high pressure conditions by a continuous flow microreactor, and triaminoguanidine hydrochloride can be synthesized more quickly and safely.

[0046] Exemplarily, a continuous flow micro-reaction module is designed and constructed, and guanidine hydrochloride is dissolved in 80% hydrazine hydrate accounting for half of the reaction amount under a nitrogen atmosphere to obtain a homogeneous material A; the remaining half of the reaction amount of 80% hydrazine hydrate is used as material B. By adjusting the liquid flow meter, the feed rate of A is adjusted to 16mL / min, and the feed rate of material B is controlled at 10mL / min. Material A and material B are passed into the micro-reaction module for continuous synthesis reaction and then flow into the product storage tank. This synthesis method is safe and green, and the product purity and yield are high, which reduces the cost of its industrial production.

[0047] Compared with the prior art, the present invention has at least the following beneficial effects:

[0048] The continuous flow synthesis method of triaminoguanidine hydrochloride provided by the present invention uses commercially available guanidine hydrochloride and hydrazine hydrate as raw materials, and reacts in a microchannel reactor to obtain triaminoguanidine hydrochloride, and the yield can reach 90.1%. The synthesis method is easy to operate, which increases the convenience of production; at the same time, the reaction time is greatly shortened, thereby improving the production efficiency; in addition, the synthesis method has a stable yield without amplification effect, and reduces the accumulation of ammonia per unit time in production, improves the safety of production, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic flow diagram of the continuous flow synthesis method of triaminoguanidine hydrochloride in Examples 1-8;

[0050] Figure 2 This is a sample diagram of triaminoguanidine hydrochloride, the product obtained in Example 1;

[0051] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the product triaminoguanidine hydrochloride obtained in Example 1. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0053] The following Examples 1-8 are all synthesized using a continuous flow synthesis method, and the schematic flow diagram thereof is shown in FIG. Figure 1 shown.

[0054] Example 1

[0055] This embodiment provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the method comprising the following steps:

[0056] (1) Guanidine hydrochloride (95.0 g, 1.0 mol, 1.0 eq) and 80% hydrazine hydrate (142.5 mL, 2.4 mol, 2.4 eq) were mixed without adding other solvents to form a homogeneous material A, and 80% hydrazine hydrate (62.5 mL, 1.0 mol, 1.0 eq) was taken as material B;

[0057] (2) Add material A and material B into the microchannel reactor, material A is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 17.8 mL / min, and material B is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 5.0 mL / min. The process gauge pressure of the continuous flow microreactor is controlled to be 0.1 MPa, the reaction temperature is 110°C, the reaction residence time is 1.8 min, and the continuous working time is 12.5 min. Cool to room temperature, filter, wash the filter cake with 1,4-dioxane, and dry it naturally to obtain a white pure triaminoguanidine hydrochloride product (such as Figure 2 shown).

[0058] like Figure 3 As shown, the product triaminoguanidine hydrochloride obtained in this example has no obvious impurity peaks in the nuclear magnetic resonance hydrogen spectrum, and its characterization data are as follows:

[0059] 1 H NMR (700MHz, DMSO-d6) δ4.50 (s, 6H), 1.24 (s, 2H).

[0060] The melting point of the triaminoguanidine hydrochloride obtained in this example was measured using a melting point apparatus and found to be 235°C.

[0061] Example 2

[0062] This embodiment provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the method comprising the following steps:

[0063] (1) Guanidine hydrochloride (95.0 g, 1.0 mol, 1.0 eq) and 80% hydrazine hydrate (205 mL, 3.4 mol, 3.4 eq) were mixed without adding other solvents to form a homogeneous material A.

[0064] (2) Add the homogeneous material A to the microchannel reactor, feed the microchannel reactor through a liquid plunger pump, the feed flow rate is 20 mL / min, the process gauge pressure of the continuous flow microreactor is controlled to be 0.1 MPa, the reaction temperature is 110°C, the reaction residence time is 2.0 min, and the continuous working time is 14.3 min. Cool to room temperature, filter, wash the filter cake with 1,4-dioxane, and dry naturally to obtain a white pure triaminoguanidine hydrochloride product.

[0065] Example 3

[0066] This embodiment provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the method comprising the following steps:

[0067] (1) Guanidine hydrochloride (95.0 g, 1.0 mol, 1.0 eq) and 80% hydrazine hydrate (142.5 mL, 2.4 mol, 2.4 eq) were mixed without adding other solvents to form a homogeneous material A, and 80% hydrazine hydrate (62.5 mL, 1.0 mol, 1.0 eq) was taken as material B;

[0068] (2) Add material A and material B into the microchannel reactor, material A is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 3.6 mL / min, and material B is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 1.0 mL / min. The process gauge pressure of the continuous flow microreactor is controlled to be 0.1 MPa, the reaction temperature is 110°C, the reaction residence time is 8.8 min, and the continuous working time is 62.0 min. Cool to room temperature, filter, wash the filter cake with 1,4-dioxane, and dry naturally to obtain white triaminoguanidine hydrochloride pure product.

[0069] Example 4

[0070] This embodiment provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the method comprising the following steps:

[0071] (1) Guanidine hydrochloride (95.0 g, 1.0 mol, 1.0 eq) and 80% hydrazine hydrate (133.4 mL, 2.2 mol, 2.2 eq) were mixed without adding other solvents to form a homogeneous material A, and 80% hydrazine hydrate (133.4 mL, 2.2 mol, 2.2 eq) was taken as material B;

[0072] (2) Add material A and material B into the microchannel reactor, material A is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 16.0 mL / min, and material B is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 10.0 mL / min. The process gauge pressure of the continuous flow microreactor is controlled to be 0.1 MPa, the reaction temperature is 110°C, the reaction residence time is 1.6 min, and the continuous working time is 13.3 min. Cool to room temperature, filter, wash the filter cake with 1,4-dioxane, and dry naturally to obtain white triaminoguanidine hydrochloride pure product.

[0073] Example 5

[0074] This embodiment provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the method comprising the following steps:

[0075] (1) Guanidine hydrochloride (95.0 g, 1.0 mol, 1.0 eq) and 80% hydrazine hydrate (133.4 mL, 2.2 mol, 2.2 eq) were mixed without adding other solvents to form a homogeneous material A, and 80% hydrazine hydrate (133.4 mL, 2.2 mol, 2.2 eq) was taken as material B;

[0076] (2) Add material A and material B into the microchannel reactor, material A is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 16.0 mL / min, and material B is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 10.0 mL / min. The process gauge pressure of the continuous flow microreactor is controlled to be 0.1 MPa, the reaction temperature is 90°C, the reaction residence time is 1.6 min, and the continuous working time is 13.3 min. Cool to room temperature, filter, wash the filter cake with 1,4-dioxane, and dry naturally to obtain white triaminoguanidine hydrochloride pure product.

[0077] Example 6

[0078] This embodiment provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the method comprising the following steps:

[0079] (1) Guanidine hydrochloride (95.0 g, 1.0 mol, 1.0 eq) and 80% hydrazine hydrate (142.5 mL, 2.4 mol, 2.4 eq) were mixed without adding other solvents to form a homogeneous material A, and 80% hydrazine hydrate (100.7 mL, 1.6 mol, 1.6 eq) was taken as material B;

[0080] (2) Add material A and material B into the microchannel reactor, material A is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 22.1 mL / min, and material B is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 10.0 mL / min. The process gauge pressure of the continuous flow microreactor is controlled to be 0.1 MPa, the reaction temperature is 110°C, the reaction residence time is 1.3 min, and the continuous working time is 10.1 min. Cool to room temperature, filter, wash the filter cake with 1,4-dioxane, and dry naturally to obtain white triaminoguanidine hydrochloride pure product.

[0081] Example 7

[0082] This embodiment provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the method comprising the following steps:

[0083] (1) Guanidine hydrochloride (95.0 g, 1.0 mol, 1.0 eq) and 475 mL of 1,4-dioxane were mixed to form a homogeneous material A, and 80% hydrazine hydrate (205 mL, 3.4 mol, 3.4 eq) was used as material B;

[0084] (2) Add material A and material B into the microchannel reactor, material A is fed into the microchannel reactor by a liquid plunger pump, the feed flow rate is 27.8 mL / min, material B is fed into the microchannel reactor after being measured by a liquid flow meter, the feed flow rate is 10.0 mL / min, the process gauge pressure of the continuous flow microreactor is controlled to be 0.1 MPa, the reaction temperature is 100°C, the reaction residence time is 1.1 min, and the continuous working time is 20.1 min. Cool to room temperature, filter, wash the filter cake with 1,4-dioxane, and dry naturally to obtain white triaminoguanidine hydrochloride pure product.

[0085] Example 8

[0086] This embodiment provides a continuous flow synthesis method of triaminoguanidine hydrochloride, the method comprising the following steps:

[0087] (1) Guanidine hydrochloride (5.0 kg, 52.7 mol, 1 eq) and 80% hydrazine hydrate (10.0 L, 165.5 mol, 3.1 eq) were mixed without adding other solvents to form a homogeneous material A, and 80% hydrazine hydrate (4 L, 62.2 mol, 1.3 eq) was taken as material B;

[0088] (2) Add material A and material B into the microchannel reactor, material A is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 33.3 mL / min, and material B is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 9.5 mL / min. The process gauge pressure of the continuous flow microreactor is controlled to be 0.1 MPa, the reaction temperature is 110°C, the reaction residence time is 1.6 min, and the continuous working time is 7 h. Cool to room temperature, filter, wash the filter cake with 1,4-dioxane, and dry naturally to obtain white triaminoguanidine hydrochloride pure product.

[0089] Comparative Example 1

[0090] This comparative example provides a method for synthesizing triaminoguanidine hydrochloride, which comprises the following steps:

[0091] Guanidine hydrochloride (95.0 g, 1.0 mol, 1.0 eq) was mixed with 80% hydrazine hydrate (205 mL, 3.4 mol, 3.4 eq), stirred and heated to 100°C, and the timing was started when the internal temperature was stabilized at 96°C, and the reaction was refluxed for 8 hours. A large number of bubbles were generated during the reaction. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter cake was washed with ethyl acetate and dried naturally to obtain white triaminoguanidine hydrochloride.

[0092] The yields of triaminoguanidine hydrochloride obtained in the above Examples 1-8 and Comparative Example 1 are shown in Table 1.

[0093] Table 1

[0094] Test items Yield of triaminoguanidine hydrochloride (%) Example 1 90.1 Example 2 88.4 Example 3 88.7 Example 4 89.8 Example 5 89.6 Example 6 90.0 Example 7 86.4 Example 8 89.9 Comparative Example 1 82.3

[0095] In summary, the continuous synthesis method of triaminoguanidine hydrochloride provided by the present invention uses commercially available guanidine hydrochloride and hydrazine hydrate as raw materials, and reacts in a continuous flow microreactor to obtain triaminoguanidine hydrochloride, and the yield can reach 90.1%. The synthesis method provided by the present invention is easy to operate, increases the convenience of production, and has good product uniformity; at the same time, the reaction time is greatly shortened, thereby improving production efficiency; in addition, the yield of the synthesis method is stable and there is no amplification effect, and the cumulative amount of ammonia per unit time is greatly reduced in production, which improves the safety of production and is suitable for large-scale industrial production.

[0096] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A continuous flow synthesis method of triaminoguanidine hydrochloride, characterized in that: The continuous flow synthesis method comprises the following steps: Adding material A and material B into a microchannel reactor to react to obtain the triaminoguanidine hydrochloride; Wherein, the material A comprises guanidine hydrochloride and a solvent; The material B comprises hydrazine hydrate.

2. The continuous flow synthesis method according to claim 1, characterized in that: The material A is fed into the microchannel reactor via a liquid plunger pump; Preferably, the feed flow rate of material A is 1-50 mL / min, more preferably 3.5-40 mL / min.

3. The continuous flow synthesis method according to claim 1 or 2, characterized in that: The volume molar concentration of guanidine hydrochloride in the material A is 2.1-8 mol / L.

4. The continuous flow synthesis method according to any one of claims 1 to 3, characterized in that: The solvent in the material A includes hydrazine hydrate and / or an organic solvent; Preferably, the mass percentage concentration of the hydrazine hydrate is 75-85%; Preferably, the organic solvent includes any one of 1,4-dioxane, N,N-dimethylacetamide or N,N-dimethylformamide, or a combination of at least two thereof.

5. The continuous flow synthesis method according to any one of claims 1 to 4, characterized in that: The material B is fed into the microchannel reactor through a liquid plunger pump; Preferably, the feed flow rate of material B is 1-20 mL / min, more preferably 1-10 mL / min.

6. The continuous flow synthesis method according to any one of claims 1 to 5, characterized in that: The molar ratio of the guanidine hydrochloride to the total amount of hydrazine hydrate in material A and material B is 1:(3-10); Preferably, the molar ratio of the guanidine hydrochloride to the total amount of hydrazine hydrate in material A and material B is 1:(3.4-5).

7. The continuous flow synthesis method according to any one of claims 1 to 6, characterized in that: The gauge pressure in the microchannel reactor is set to 0.1-0.5 MPa.

8. The continuous flow synthesis method according to any one of claims 1 to 7, characterized in that: The residence time of the reaction is 1-30min; Preferably, the reaction temperature is 60-120°C, more preferably 90-120°C.

9. The continuous flow synthesis method according to any one of claims 1 to 8, characterized in that: After the reaction is completed, a post-processing process is also included; Preferably, the post-treatment process includes cooling the reaction solution to room temperature, filtering, washing and drying; Preferably, the washing agent used in the washing comprises any one of ethyl acetate, 1,4-dioxane, petroleum ether or dichloromethane, or a combination of at least two thereof; Preferably, the drying includes any one of natural air drying, oven drying or infrared lamp drying.

10. The continuous flow synthesis method according to any one of claims 1 to 9, characterized in that: The continuous flow synthesis method specifically comprises the following steps: (1) guanidine hydrochloride and a solvent are uniformly mixed to prepare a guanidine hydrochloride solution with a volume molar concentration of 2.1-8 mol / L to obtain material A; hydrazine hydrate with a mass percentage concentration of 75-85% is used as material B; (2) adding material A and material B into a microchannel reactor, reacting at a gauge pressure of 0.1-0.5 MPa and 60-120° C., with a reaction residence time of 1-30 min. After the reaction is completed, cooling the reaction solution to room temperature, filtering with suction, washing the filter cake with a detergent, and drying to obtain the triaminoguanidine hydrochloride; The material A is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 1-50 mL / min; The solvent in the material A includes hydrazine hydrate and / or an organic solvent, and the organic solvent includes any one or a combination of at least two of 1,4-dioxane, N,N-dimethylacetamide or N,N-dimethylformamide; The material B is fed into the microchannel reactor through a liquid plunger pump, and the feed flow rate is 1-20 mL / min; The molar ratio of the guanidine hydrochloride to the total amount of hydrazine hydrate in material A and material B is 1:(3-10); The washing agent used in the washing includes any one of ethyl acetate, 1,4-dioxane, petroleum ether or dichloromethane, or a combination of at least two thereof; The drying includes any one of natural air drying, oven drying or infrared lamp drying.

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