阅读说明：本技术 一种1,3,5-三羟基-2,4,6-三硝基苯的制备方法 (Preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene ) 是由 姜维 杨光成 张祯琦 王银 刘志伟 胡林强 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种1,3,5-三羟基-2,4,6-三硝基苯的制备方法,包括步骤：(1)取间苯三酚、浓硫酸、硫酸铵混合得物料1,将物料1进料到微通道反应器的预冷模块进行预冷；(2)取发烟硝酸,与预冷后的物料1同时进料到微通道反应器的混合模块,混合均匀得物料2；(3)将物料2进料到微通道反应器的反应模块,得到含1,3,5-三羟基-2,4,6-三硝基苯的混合液；(4)将步骤(3)中得到的混合液进料到装有水的微通道反应器的收集模块,搅拌、过滤、干燥即得目标产物。以发烟硝酸与硫酸铵为硝化试剂,发烟硝酸用量少,显著减少废酸产生。整个制备过程在微通道反应器内进行,反应缩短反应时间,反应过程容易控制。(The invention discloses a preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene, which comprises the following steps: (1) mixing phloroglucinol, concentrated sulfuric acid and ammonium sulfate to obtain a material 1, and feeding the material 1 into a precooling module of a microchannel reactor for precooling; (2) taking fuming nitric acid, feeding the fuming nitric acid and the precooled material 1 into a mixing module of a microchannel reactor at the same time, and uniformly mixing to obtain a material 2; (3) feeding the material 2 into a reaction module of a microchannel reactor to obtain a mixed solution containing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene; (4) and (4) feeding the mixed solution obtained in the step (3) into a collection module of a microchannel reactor filled with water, stirring, filtering and drying to obtain the target product. Fuming nitric acid and ammonium sulfate are used as nitration reagents, the fuming nitric acid is low in consumption, and waste acid is remarkably reduced. The whole preparation process is carried out in the microchannel reactor, the reaction time is shortened, and the reaction process is easy to control.)

1. A preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene is characterized by comprising the following steps:

(1) mixing phloroglucinol, concentrated sulfuric acid and ammonium sulfate to obtain a material 1, and feeding the material 1 into a precooling module of a microchannel reactor for precooling;

(2) taking fuming nitric acid, feeding the fuming nitric acid and the precooled material 1 into a mixing module of a microchannel reactor at the same time, and uniformly mixing to obtain a material 2;

(3) feeding the material 2 into a reaction module of a microchannel reactor to obtain a mixed solution containing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene;

(4) and (4) feeding the mixed solution obtained in the step (3) into a collection module of a microchannel reactor filled with water, stirring, filtering and drying to obtain the target product.

2. The preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the mass ratio of phloroglucinol, fuming nitric acid and ammonium sulfate is 100: (180.0-200.0): (190-200.0).

3. The method for preparing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the mass-to-volume ratio of phloroglucinol to concentrated sulfuric acid is 1: (15-35) g/mL.

4. The method for preparing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the mass fraction of concentrated sulfuric acid is greater than or equal to 90%.

5. The preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the mass fraction of fuming nitric acid is greater than or equal to 95%.

6. The method for preparing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the pre-cooling zone temperature of the pre-cooling module in step (1) is 10-55 ℃ and the pre-cooling time is 0.5-2 minutes.

7. The method for preparing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the temperature of the mixing zone of the mixing module in step (2) is 10-55 ℃ and the mixing time is 0.5-2 minutes.

8. The method for preparing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the temperature of the reaction zone of the reaction module in the step (3) is 10-55 ℃ and the reaction time is 0.5-10 minutes.

9. The method for preparing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the temperature of water in the collection module in the step (4) is 0-10 ℃, and the stirring time in the collection module is 0.5-2 hours.

10. The method for preparing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to claim 1, wherein the volume ratio of concentrated sulfuric acid to water in the collection module is 1: (2-10).

Technical Field

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene.

Background

1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene is widely applied to chemical industrial production of explosives, dyes, pigments, rubber and the like as nitrophenol compounds.

At present, the production process of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene mainly uses phloroglucinol as a raw material to carry out nitration reaction with a nitration reagent. Commonly used nitrating agents are (1) fuming nitric acid or mixed acids; (2) fuming nitric acid and ammonium sulfate. When fuming nitric acid or mixed acid is used as a nitrating reagent, the selectivity of the product 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene obtained by the reaction is low, other byproducts are easily generated, the subsequent purification is difficult, and the yield is low; and fuming nitric acid or mixed acid is used as a nitrating reagent to generate more waste acid. When fuming nitric acid and ammonium sulfate are used as nitration reagents, the condition of many byproducts still exists, and meanwhile, the ammonium sulfate is a civil explosive, so that mass production cannot be realized through mass purchase, and industrialization cannot be realized.

Meanwhile, the existing production of the 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene is carried out in a reaction kettle, the reaction time needs several hours, the reaction process is an exothermic reaction, the generation of byproducts is also aggravated due to high temperature and long reaction time in a reaction system, and potential safety hazards exist. And the reaction time and the post-treatment time of the reaction kettle are long, the operation is complicated, the yield is low, and the requirement on the market timeliness cannot be met.

Therefore, it is highly desirable to develop a method for preparing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene with shorter reaction time and higher selectivity so as to obtain 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene with high yield and high purity.

Based on this, the present patent application is proposed.

Disclosure of Invention

The invention aims to solve the technical problems of long reaction time, complex post-treatment and difficulty, low yield and purity and incapability of adapting to industrial production in the existing production process of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene, and aims to provide a preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene, so that the problems of long reaction time, complex post-treatment and difficulty, and low yield and purity in the existing preparation method are solved.

The invention is realized by the following technical scheme:

a preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene comprises the following steps:

(1) mixing phloroglucinol, concentrated sulfuric acid and ammonium sulfate to obtain a material 1, and feeding the material 1 into a precooling module of a microchannel reactor for precooling;

(2) taking fuming nitric acid, feeding the fuming nitric acid and the precooled material 1 into a mixing module of a microchannel reactor at the same time, and uniformly mixing to obtain a material 2;

(3) feeding the material 2 into a reaction module of a microchannel reactor to obtain a mixed solution containing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene;

(4) and (4) feeding the mixed solution obtained in the step (3) into a collection module of a microchannel reactor filled with water, stirring, filtering and drying to obtain the target product.

Preferably, the mass ratio of the phloroglucinol to the fuming nitric acid to the ammonium sulfate is 100: (180.0-200.0): (190 to 200.0), more preferably 100: 185: 195.

preferably, the mass-to-volume ratio of the phloroglucinol to the concentrated sulfuric acid is 1: (15-35) g/mL, more preferably 25 g/mL.

Preferably, the mass fraction of the concentrated sulfuric acid is greater than or equal to 90%, more preferably greater than or equal to 98%, and most preferably 98%.

Preferably, the mass fraction of fuming nitric acid is equal to or greater than 95%, more preferably equal to or greater than 95%.

Preferably, the pre-cooling module in the step (1) has a pre-cooling zone temperature of 10-55 ℃ and a pre-cooling time of 0.5-2 minutes, and more preferably has a pre-cooling zone temperature of 35-55 ℃.

Preferably, the temperature of a mixing area of the mixing module in the step (2) is 10-55 ℃, the mixing time is 0.5-2 minutes, and the temperature of the mixing area is more preferably 35-55 ℃; most preferably the mixing zone temperature is 10 ℃ and the mixing time is 1 minute.

Preferably, the temperature of a reaction area of the reaction module in the step (3) is 10-55 ℃, and the reaction time is 0.5-10 minutes; more preferably, the temperature in the reaction zone is 35 to 55 ℃, most preferably the temperature in the reaction zone is 10 ℃, and the reaction time is 1 minute.

Preferably, the temperature of water in the collection module in the step (4) is 0-10 ℃, and the stirring time in the collection module is 0.5-2 hours, more preferably, the temperature of water in the collection module is 0 ℃, and the stirring time is 1 hour.

Preferably, the volume ratio of the concentrated sulfuric acid to the water in the collection module is 1: (2-10), more preferably 1: (4-5).

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. according to the preparation method of the 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene provided by the embodiment of the invention, concentrated sulfuric acid is adopted as a reaction solvent, fuming nitric acid and ammonium sulfate are adopted as nitration reagents, the concentrated sulfuric acid does not participate in substitution reaction in the reaction process, the using amount of the fuming nitric acid is greatly reduced, and the generation of waste acid is remarkably reduced. The whole preparation process is carried out in a micro-channel reactor in a continuous flow mode, the reaction time is shortened from hours of kettle type reaction to dozens of seconds to several minutes, and the reaction efficiency is obviously improved. And parameters such as reaction temperature, molar ratio of raw materials to solvent, reaction residence time and the like can be accurately controlled, and the reaction process is easy to control.

2. Compared with a kettle type preparation process, the preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene provided by the embodiment of the invention obviously improves the selectivity of synthesizing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene, and obviously improves the yield and purity of the target product 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene, wherein the yield is close to 100%, the purity reaches 99.8%, and compared with the kettle type preparation, the purity is 98.3%, and the purity is obviously improved.

In summary, the preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene provided by the embodiment of the invention has the advantages of high reaction speed, less side reactions, high heat and mass transfer efficiency, high reaction selectivity, convenience in post-treatment, high product purity and high yield, and has wide application prospects in industrial synthesis of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene.

Drawings

In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that for those skilled in the art, other related drawings can be obtained from these drawings without inventive effort. In the drawings:

fig. 1 is a flow chart of a preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not used as limitations of the present invention.

Example 1

A preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene comprises the following specific preparation steps:

(1) respectively weighing 2000mL of concentrated sulfuric acid with the mass fraction of 98% and 100g of phloroglucinol, pouring the concentrated sulfuric acid and the phloroglucinol into a beaker A, weighing 190g of ammonium sulfate, pouring the ammonium sulfate into the beaker A, and stirring and dissolving to obtain a material 1; 180g of fuming nitric acid with a mass fraction of 95% are weighed and poured into the beaker B.

(2) Respectively connecting the beaker A and the beaker B with a metering pump P1 and a metering pump P2; starting a metering pump P1, feeding the material 1 into a pre-cooling module of the microchannel reactor, controlling the temperature of a pre-cooling area at 10 ℃, and pre-cooling for 1 minute.

(3) And starting a metering pump P2, feeding fuming nitric acid and the precooled material 1 into a mixing module of the microchannel reactor simultaneously, and uniformly mixing to obtain a material 2, wherein the temperature of a mixing area of the mixing module is 10 ℃, and the mixing time is 1 minute.

(4) And feeding the material 2 into a reaction module of the microchannel reactor for continuous reaction, setting the temperature of a reaction area of the reaction module to be 10 ℃, and reacting for 1 minute to obtain a mixed solution containing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene.

(5) Then the mixed solution containing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene flows out from the outlet of the reaction module and enters a collection module of a microchannel reactor filled with 4L of ice water, the temperature of the ice water is 0 ℃, and the mixture is stirred for 1 hour. And after stirring, filtering the reaction system in the collection module, and drying the solid to obtain the target product.

The target product is weighed to obtain 131g of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene with the total yield of 99.8 percent. The purity of the target product is 99.8% by high performance liquid chromatography.

Example 2

The preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene is the same as that of example 1 except that the mass of fuming nitric acid is 190 g.

The target product is weighed to obtain 131g of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene with the total yield of 99.8 percent. The purity of the target product is 99.8% by high performance liquid chromatography.

Example 3

The preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene is the same as that of example 1 except that the mass of fuming nitric acid is 200 g.

The target product is weighed to obtain 131g of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene with the total yield of 99.8 percent. The purity of the target product is 99.8% by high performance liquid chromatography.

Example 4 Synthesis of 1,3, 5-Trihydroxyl-2, 4, 6-Trinitrobenzene in the continuous flow zone of the present invention

The preparation method of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene is the same as that of example 1 except that the volume of concentrated sulfuric acid is 1500 mL.

The target product is weighed to obtain 131g of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene with the total yield of 99.8 percent. The purity of the target product is 99.8% by high performance liquid chromatography.

Example 5 Synthesis of 1,3, 5-Trihydroxyl-2, 4, 6-Trinitrobenzene in the continuous flow zone of the present invention

A process for producing 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene, which is the same as in example 1 except that the mass of ammonium sulfate is 200g in example 1.

The target product is weighed to obtain 131g of 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene with the total yield of 99.8 percent. The purity of the target product is 99.8% by high performance liquid chromatography.

In the embodiment of the invention, concentrated sulfuric acid is used as a reaction solvent, and ammonium sulfate and fuming nitric acid are used as nitration reagents. Mixing phloroglucinol, concentrated sulfuric acid and ammonium sulfate, pumping the mixture into a precooling module of a microchannel reactor, and precooling the mixture for 0.5-2 minutes to obtain a material 1, wherein no chemical reaction is generated in the process, precooling a reaction system, controlling the temperature of each substance in the reaction system, and avoiding the excessive violent subsequent reaction process; then simultaneously pumping the material 1 and fuming nitric acid into a mixing module of the microchannel reactor and mixing for 0.5-2 minutes at low temperature, obtaining a small amount of mononitro and dinitro substitutes of phloroglucinol in the process, wherein the reaction degree is low, and the mixing arranged in the mixing module can uniformly mix all the substances, so that all the subsequent substances fully participate, also control the reaction process, buffer the heat released in the chemical reaction process in the mixing process, and avoid violent reaction and rapid heat release; after mixing in the mixing module, pumping the mixed solution containing the mononitro and dinitro substitutes of phloroglucinol into a reaction module of the microchannel reactor for reaction, wherein the reaction temperature is 10-55 ℃, and the reaction time is 0.5-10 minutes, so that the nitrated trisubstituent of phloroglucinol can be obtained, and the reaction temperature is low, the reaction time is short, the generation of byproducts is less, and the heat released by the reaction is less in the reaction process; and finally, adding the mixed solution containing the target product into water in a collection module, cooling, crystallizing and performing post-treatment to obtain the 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene.

The applicant selects fuming nitric acid and ammonium sulfate as nitration reagents through a large amount of research and experiments, prepares 1,3, 5-trihydroxy-2, 4, 6-trinitrobenzene in a microchannel reactor by utilizing continuous flow for the first time, and obtains a proper material ratio of each substance, proper time and temperature of each process, an optimized process flow and a most proper purification treatment method through a large amount of experiments and grope. Thereby greatly shortening the time of the whole preparation process, reducing the temperature of the reaction process, reducing the generation of byproducts, and obviously improving the yield and purity of the target product, wherein the purity reaches more than 99 percent. In addition, concentrated sulfuric acid is used as a reaction solvent in the reaction process, does not participate in the substitution reaction process, and is only used as the reaction solvent, so that the intensity of the reaction is reduced, the using amount of fuming nitric acid is greatly reduced, and the generation of waste acid is remarkably reduced. By utilizing the continuous flow technology, the accurate control of parameters such as reaction temperature, molar ratio of raw materials to solvent, reaction residence time and the like in the whole preparation process is realized, so that the preparation process is easy to control, and the industrial production requirement is very met.

Meanwhile, the various raw materials, reagents and equipment used in the above examples can be obtained by purchasing commercially available products. The continuous flow experimental equipment used in the invention is a commercially available microchannel reactor.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.