Preparation method of nitrification organic matter and prepared nitrification organic matter

A technology of organic matter and nitrating acid solution, which is applied in the preparation of nitro compounds, organic chemistry, chemical instruments and methods, etc. It can solve the problems of affecting the quality of chemical products, poor batch production stability, and high post-processing costs, and achieve large-scale industrial applications. value, improved production environment, and high production efficiency

Pending Publication Date: 2019-07-12

SHANDONG HIMILE CHEM TECH

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AI-Extracted Technical Summary

Problems solved by technology

[0003] The traditional process, which adopts intermittent flask or kettle production, has the following defects: (1) the heat release of p-cresol nitration reaction is large, and the phenomenon of "flying temperature" is easy to occur; (2) the condition is not well controlled, and tar-lik...

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Method used

Adopt the mode of feeding at least twice in another embodiment, nitric acid adopts the mode of subsection feeding, preferably, nitric acid adopts the mode of feeding twice; More preferably, the second feeding of nitric acid The feed time of the feed is 1/200-2/3 of the total reaction time, and more preferably, the feed time of the second feed is 1/50-2/3 of the total reaction time. It is advisable to control the secondary feeding time of nitric acid in the middle stage of the reaction, and supplement the amount of nitric acid in the middle stage. The inventors found that the method of feeding nitric acid in stages can further increase the yield of the reaction. If the nitric acid is added at one time, the reaction in the front stage of the reaction will be too violent, and the heat release will be large, resulting in an increase in temperature, increasing the occurrence of side reactions, and selectivity. Reduction; the use of nitric acid secondary feed can effectively control the reaction temperature, avoid local overheating, reduce the occurrence of side reactions, and improve selectivity.

Comparative example 9 and embodiment 10 know that, the mode that adopts nitric acid subsection feeding can further improve the selectivity of product.

Compared with conventional synthetic method, ...

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Abstract

The invention discloses a preparation method of nitrification organic matter and the prepared nitrification organic matter, and relates to the technical field of organic synthesis. The preparation method of the nitrification organic substance comprises the following steps: introducing a nitrification acid liquid and molten-state organic matter to be nitrified into a microchannel reactor, and performing a reaction, wherein the organic matter to be nitrified is solid at normal temperature, and solidification and/or dissolution in the nitrification acid liquid does not occur in the organic matterto be nitrified after the organic matter to be nitrified is introduced into the microchannel reactor. According to the preparation method of the nitrification organic matter provided by the invention, the nitrification organic matter prepared by the method has a very good yield and purity without a solvent removal post-treatment process; in the whole process, no solvent participates in the reaction, so that the post-treatment process of solvent removal is avoided; and the method has high safety in the whole reaction process, adopts automation control, has high production efficiency and a greatly-improved production environment, and has larger industrial application value.

Application Domain

Chemical/physical/physico-chemical microreactorsNitro compound preparation

Technology Topic

SolventOrganic synthesis +6

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Examples

Experimental program(19)
Comparison scheme(4)
Effect test(2)

Example Embodiment

[0022] An embodiment of the present invention provides a method for preparing nitrated organic matter, which includes the following steps: pass the nitrated acid solution and the molten organic matter to be nitrated into a microchannel reactor for reaction; preferably, the reaction residence time is more than 10s to correct Take the cresol reaction as an example, the reaction principle is as follows:

[0023]

[0024] Wherein, the organic matter to be nitrated is solid at room temperature, and after the organic matter to be nitrated in a molten state is passed into the microchannel reactor, the organic matter to be nitrated will not be solidified and/or dissolved in the nitrating acid solution. In order to ensure the state of the organic substance to be nitrated in the microchannel reactor, the reaction temperature should not be too low. Preferably, the difference between the reaction temperature and the melting point temperature of the organic substance to be nitrated is X, X≥-30°C; more preferably, X≥ -20°C; further preferably, X≥-100°C.

[0025] Specifically, non-solidification means that most materials in the molten state will not undergo phase change and become solid, even if a small amount of solidification occurs without clogging the channel, and can be dissolved in the nitrating acid solution or reacted to dissolve with the flow of the material. Preferably, non-solidification means that all molten materials will not solidify.

[0026] In some embodiments, the organic substance to be nitrated is p-nitrochlorobenzene or p-dichlorobenzene, and the nitrating acid solution is a mixed acid of nitric acid and sulfuric acid; preferably, the molar ratio of the organic substance to be nitrated, nitric acid and sulfuric acid is 1:1. 2:1.26-4; preferably, the flow rate of the organic matter to be nitrated is 12-25mL/min, and the flow rate of the nitrating acid solution is 10-40mL/min; preferably, the reaction temperature is 60-90°C, and the reaction time is 70-120min . The nitration reaction of p-nitrochlorobenzene or p-dichlorobenzene is different from p-cresol, and the nitration reaction needs to react in the presence of a mixed acid.

[0027] In a preferred embodiment, the organic substance to be nitrated is p-cresol, and the nitrating acid solution is dilute nitric acid, and p-cresol can undergo nitration reaction in the presence of dilute nitric acid without a mixed acid reaction.

[0028] Taking the reaction of p-cresol as an example, the inventor creatively uses nitric acid and molten p-cresol as raw materials, and uses a microchannel reactor to perform the reaction, avoiding the use of solvents, and the reaction residence time is short. There is no solvent involved in the reaction in the whole process, which avoids the post-treatment process of solvent removal; the whole reaction process is not prone to "flying temperature" phenomenon, high safety performance, automatic control; reaction residence time is short, no post-processing link is required, and the production efficiency is high. It has great industrial application value.

[0029] Please refer to figure 1 , Microchannel reactor is a continuous flow pipeline reactor. It is a device manufactured by micromachining technology with a characteristic size between 10-1000μm and controlling chemical reactions in a small reaction space. The narrow microchannel in the microreactor shortens the distance and time of mass transfer. At the same time, the increased specific surface area also provides a larger place for the mass transfer process, so as to achieve rapid mixing of the reaction materials, making it within milliseconds to microseconds. Radial complete mixing is achieved within the range of stages. The narrow microchannels of the microreactor also increase the temperature gradient, and the increased specific surface area greatly enhances the heat transfer capability of the reactor. Therefore, the characteristics of the microchannel reactor enable it to maximize the chemical reaction process and increase the reaction efficiency, so that the chemical reaction rate is close to its reaction kinetic limit.

[0030] Compared with conventional synthesis methods, the present invention adopts pipeline reactors such as micro-channel reactors to continuously prepare o-nitro-p-cresol, which has the following advantages: no solvent is used, post-treatment process is reduced; equipment area is small, and operation is simple , Easy to control and scale up; and the inventor found that the o-nitro-p-cresol product prepared by this method has high purity and stable quality.

[0031] in figure 1 It consists of a p-cresol container 1, a nitric acid container 3, a metal high-pressure constant flow pump 4, a microchannel reactor 5, and a sampling bottle 6. The metal high-pressure constant flow pump 4 feeds the two raw materials into the microchannel for reaction. The reaction is carried out in the vessel 5, and then the sample is passed into the sampling bottle 6. Depending on the residence time of the reaction, there may be a certain difference in sampling points, such as Figure 2-3 status. A heating jacket (such as water bath 2) is provided on the material feeding pipeline of the molten feed. The temperature of the heating jacket does not cause the molten feed to solidify, for example, the melting point of the material minus 10°C.

[0032] Specifically, p-cresol (industrial grade raw material) needs to be heated to a molten state, such as heated to 40°C, before being passed into the reactor. Nitric acid is 20-40% dilute nitric acid (industrial grade raw material); preferably 25-35%; more preferably 28-32%. Dilute nitric acid can be obtained by diluting commercially available nitric acid with a volume fraction of 65%. It is advisable to control the concentration of nitric acid within the above range. Within this range, the reaction process is easy to control, and the phenomenon of "flying temperature" is not easy to occur.

[0033] In order to increase the yield of the product, the amount of the two raw materials needs to be controlled within a certain range, and the molar ratio of p-cresol and nitric acid is 1:1.1-1.2. A slight excess of nitric acid is used to make the p-cresol react more fully and ensure the yield of o-nitro p-cresol.

[0034] The microchannel reactor used in the embodiment of the present invention may be a commercially available conventional microchannel reactor, preferably a reactor independently developed and produced by Shandong Haomai Chemical Technology Co., Ltd., and the specific patent numbers are 201610932350.0 and 201610965286.6. The channel depth of the microchannel reactor is 0.3-1.0mm, and the total liquid holding capacity is 10-100mL (can be adjusted according to actual needs, such as 60.0mL, 40.0mL, 20.0mL, etc.); the channel is in the form of an umbrella, and the The channel reactor adopts a double-sided heat exchange structure. The processing of the microchannel reactor is mainly realized by micro-processing techniques such as etching, wire cutting, and laser drilling.

[0035] In some embodiments, one-time feed is adopted, the flow rate of p-cresol is 10-40 mL/min, and the flow rate of nitric acid is 20-90 mL/min; preferably, the flow rate of p-cresol is 25-30 mL/min, The flow rate of nitric acid is 30-45 mL/min. The flow rate of p-cresol and nitric acid is controlled within the above range, which can adapt to the structure of the microchannel reactor, so that the reaction is completed in a short time, and the production efficiency is improved.

[0036] In another embodiment, at least two feeds are used, and nitric acid is fed in stages. Preferably, nitric acid is fed in two feeds; more preferably, the feeding of the second feed of nitric acid is The feeding time is 1/200-2/3 of the total reaction time. More preferably, the feeding time of the second feeding is 1/50-2/3 of the total reaction time. It is advisable to control the secondary feeding time of nitric acid in the middle of the reaction, and to supplement the amount of nitric acid in the middle. The inventor found that the stepwise feeding method of nitric acid can further increase the yield of the reaction. If nitric acid is added at one time, the reaction in the front stage of the reaction will be too violent and the exothermic heat will increase, which will increase the temperature and increase the occurrence of side reactions and selectivity. Reduce; the use of nitric acid secondary feed can effectively control the reaction temperature, avoid excessive local temperature, reduce the occurrence of side reactions, and improve selectivity.

[0037] In some embodiments, three feeds are used. Preferably, the second feed timing is selected at 1/200-3/6 of the reaction residence time t; the third feed timing is selected at the reaction residence time t Time 3/6-5/6.

[0038] Optionally, preferably, when the number of feedings is n times and 2n≤200, 200 is selected, and the m-th feeding time is (2m-1)/200-(2m+1) of the total reaction time t /200; Preferably, when the number of feedings is n times and 2n>200, the m-th feeding time is (2m-1)/2n-(2m+1)/2n of the total reaction time t.

[0039] What needs to be added is that the stepwise feeding method is adopted, and the overall structure of the reaction is shown as image 3 Shown, compared with Figure 1-2 It adds a set of metal high pressure constant flow pumps to transport nitric acid.

[0040] Further, the secondary feed is generally faster than the primary feed. For example, during the first feed, the flow rate of p-cresol is 30-45 mL/min, and the flow rate of nitric acid is 20-30 mL/min; When feeding, the flow rate of nitric acid is 50-65mL/min; preferably, when feeding for the first time, the flow rate of p-cresol is 35-40mL/min, and the flow rate of nitric acid is 23-28mL/min; for the second feeding At this time, the flow rate of nitric acid is 55-60 mL/min. The flow rate of the second feed of nitric acid should be faster, so as to fully react within a suitable reaction residence time. Too slow or too fast of the second feed of nitric acid flow rate is not conducive to the increase of the yield, and it is controlled at 55-60mL/ min is appropriate.

[0041] Further, the reaction residence time is 10-60s; preferably 15-40s; more preferably 19-21s. The synthesis process provided by the embodiment of the present invention can complete the reaction in a short time, and the reaction residence time of about 10s or more o-nitro-p-cresol can achieve a high yield, in order to further improve the o-nitro-p-cresol It is advisable to control the residence time of the reaction at about 20s.

[0042] Further, the reaction temperature is 20-40°C; preferably 25-35°C; more preferably 29-31°C. The reaction temperature should not be too high or too low. If the reaction temperature is too low, the reaction will not proceed completely, and the yield of o-nitro-p-cresol will be low; if the reaction temperature is too high, the reaction will not be easy to control, and the phenomenon of "flying temperature" will easily occur.

[0043] The embodiment of the present invention also provides a kind of o-nitro-p-cresol, which is prepared by applying the above-mentioned method for preparing nitrated organic matter. In a preferred embodiment, the conversion rate of o-nitro-p-cresol is more than 98%, and the purity of o-nitro-p-cresol is more than 98%. The o-nitro-p-cresol prepared by the above preparation method has the advantages of short production cycle, high yield, high product purity, etc., and has good market competitiveness.

Example Embodiment

[0045] Example 1

[0046] This embodiment provides a method for preparing nitrated organic matter (o-nitro-p-cresol), which includes the following steps:

[0047] Connect two metal high-pressure constant flow pumps with the first two feed ports of the microchannel reactor, and wash them with solvent water. The sampling bottle is cleaned, dried, and then connected to the sixth discharge port of the microchannel reactor. After the microchannel reactor is rinsed with solvent, it is filled with 30% nitric acid solution.

[0048] The temperature of the microchannel reactor is set to 20℃, the p-cresol is heated to a molten state in a water bath or a thermostat, the molar ratio of p-cresol and nitric acid is set to 1:1.3, p-cresol and 30% nitric acid The flow rates of the solution were 18.5mL/min and 41.5mL/min, respectively, and they were mixed in the microchannel reactor with a residence time of 60s (effective holding capacity of 60.0mL). During the reaction, the temperature was controlled at about 20°C, and the reaction liquid was collected to determine the content of o-nitro-p-cresol.

Example Embodiment

[0049] Example 2

[0050] This embodiment provides a method for preparing nitrated organic matter (o-nitro-p-cresol), which includes the following steps:

[0051] Connect two metal high-pressure constant flow pumps with the first two feed ports of the microchannel reactor, and wash them with solvent water. The sampling bottle is cleaned, dried, and then connected to the sixth discharge port of the microchannel reactor. After the microchannel reactor is rinsed with solvent, it is filled with 30% nitric acid solution.

[0052] The temperature of the microchannel reactor is set to 30°C, the p-cresol is heated to 40°C in a water bath or in a constant temperature box, and the molar ratio of p-cresol to nitric acid is set to 1:1.3. The flow rates of the% nitric acid solution are 18.5 mL/min and 41.5 mL/min, respectively, and enter the microchannel reactor for mixing, and the residence time is 60 s (the effective holding capacity is 60.0 mL). During the reaction, the temperature was controlled at about 30°C, and the reaction liquid was collected to determine the content of o-nitro-p-cresol.

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Description & Claims & Application Information

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Classification and recommendation of technical efficacy words

Increase productivity
Improve safety performance

Apparati, methods, and compositions for universal microbial diagnosis, detection, quantification, and specimen-targeted therapy

InactiveUS20120129794A1Increase productivityAccurate and rapid and sensitive microbial diagnosis and detection and quantificationAntibacterial agentsBiocidePopulationMolecular Targeted Therapies

Owner:DOWD SCOT E +2

Automatic glue spreading machine

ActiveCN101920238AIncrease productivityPrecise positioningLiquid surface applicatorsCell electrodesManipulator

Owner:DONGGUAN AMPEREX TECH +1

Preparation method of nitrification organic matter and prepared nitrification organic matter

AI-Extracted Technical Summary

Problems solved by technology

Method used

Abstract

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Examples

Example Embodiment

Example Embodiment

Example Embodiment

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Description & Claims & Application Information

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