CN111303003B - Olive-shaped N-methyl-4-nitrophthalimide crystal and preparation method thereof - Google Patents
Olive-shaped N-methyl-4-nitrophthalimide crystal and preparation method thereof Download PDFInfo
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- CN111303003B CN111303003B CN201811516453.4A CN201811516453A CN111303003B CN 111303003 B CN111303003 B CN 111303003B CN 201811516453 A CN201811516453 A CN 201811516453A CN 111303003 B CN111303003 B CN 111303003B
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- C07D209/00—Heterocyclic compounds containing five-membered rings, condensed with other rings, with one nitrogen atom as the only ring hetero atom
- C07D209/02—Heterocyclic compounds containing five-membered rings, condensed with other rings, with one nitrogen atom as the only ring hetero atom condensed with one carbocyclic ring
- C07D209/44—Iso-indoles; Hydrogenated iso-indoles
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Abstract
The invention relates to an olive-shaped N-methyl-4-nitrophthalimide crystal and a preparation method thereof, wherein the method comprises the following steps: a) reacting N-methylphthalimide with fuming nitric acid in a concentrated sulfuric acid system to prepare a concentrated sulfuric acid solution of N-methyl-4-nitrophthalimide; b) pouring the concentrated sulfuric acid solution of the N-methyl-4-nitrophthalimide into low-temperature water, stirring, separating out N-methyl-4-nitrophthalimide solid, washing with water and drying; c) and refluxing and cooling the dried N-methyl-4-nitrophthalimide solid, filtering and drying to obtain olive-shaped N-methyl-4-nitrophthalimide crystals. The invention solves the problem that the heat accumulation is easy to cause danger in the production process in the prior art, and also solves the problems of small bulk density of product crystals, difficult feeding in downstream synthesis application and low product yield.
Description
Technical Field
The invention relates to an N-methyl-4-nitrophthalimide crystal and a preparation method thereof, belonging to the technical field of fine chemical synthesis.
Background
The N-methyl-4-nitrophthalimide crystal is an important intermediate for synthesizing polyimide materials such as polyetherimide, polyesterimide, polybenzimide and the like. The structure is as follows:
Many publications report the preparation of this substance (see: Zhengkai, Yao Cheng.4-nitro-N-methyl-phthalimide synthesis new process [ J ]; petro chemical industry, 2004, 33 (2): 145 cohai 148, Zhengkai, Yao Cheng.4-nitro-N-methyl-phthalimide synthesis new process research [ J ]. Jiangsu chemical industry, 2003, 31 (6): 39-41.), the prior art is as follows: dissolving N-methyl-4-nitrophthalimide in concentrated sulfuric acid, dropwise adding fuming nitric acid into the system, controlling the reaction temperature below 10 ℃, maintaining for several hours, heating the system to below 80 ℃ and reacting for several hours, thus obtaining the product yield of more than 80%.
The inventor of the application finds that the method has great problems in the practical research process, namely, the phenomenon of heat accumulation can occur when the nitration reaction is carried out at a low temperature, and potential safety hazards can be caused; secondly, the yield of the product is low; thirdly, the solid bulk density of the N-methyl-4-nitrophthalimide prepared by the method is small, and the phenomena of difficult feeding, low yield of downstream products and the like are generated when the downstream products are synthesized.
Disclosure of Invention
The invention aims to solve the problems of safety of nitration reaction and difficult feeding and low yield in application of downstream products.
The technical scheme adopted by the invention is as follows:
a method for preparing olivine N-methyl-4-nitrophthalimide crystals, comprising the steps of: a) reacting N-methylphthalimide with fuming nitric acid in a concentrated sulfuric acid system to prepare a concentrated sulfuric acid solution of N-methyl-4-nitrophthalimide; b) pouring a concentrated sulfuric acid solution of N-methyl-4-nitrophthalimide into low-temperature water, stirring to separate out N-methyl-4-nitrophthalimide solid, washing the solid with water until the filtrate is neutral, and drying (preferably under normal pressure); c) and (3) putting the dried N-methyl-4-nitrophthalimide solid into an ester solvent for dissolving phosphate and organic base, refluxing and cooling, and filtering and drying (preferably vacuum drying) the mixture to obtain olive-shaped N-methyl-4-nitrophthalimide crystals.
Further, the concentrated sulfuric acid is 93-98 wt%; the concentration of the fuming nitric acid is 85-98 wt%, and preferably 95-98 wt%.
Furthermore, the mass ratio of the N-methyl-4-nitrophthalimide to the concentrated sulfuric acid and the fuming nitric acid is 1: 2-5: 0.2-3, preferably 1: 3-3.6: 0.3-1.5, and more preferably 1: 3-3.1: 0.4-1.1.
Further, in the step a), adding the N-methyl-4-nitrophthalimide solid into concentrated sulfuric acid with stirring started, gradually heating to dissolve, gradually dropwise adding fuming nitric acid into the reaction system, reacting for a period of time, and cooling to normal temperature, wherein the temperature for heating and dissolving the N-methylphthalimide is selected from 30-60 ℃, and preferably 35-45 ℃; the system temperature controlled during the dropwise addition of the nitric acid is 30-100 ℃; the reaction time is 1.5 to 5 hours, preferably 2 to 3 hours.
Further, in the step b), the low-temperature water is selected from an ice-water mixture and water with the temperature of 0-15 ℃, and is preferably the ice-water mixture; the mass of the low-temperature water is 2.5-5 times, preferably 3-4 times of the theoretical yield of the N-methyl-4-nitrophthalimide; the pH value of the washed filtrate is neutral and is 6-8; the drying temperature is 80-120 ℃, and preferably 90-100 ℃.
Further, in step c), the solvent for reflux washing is selected from esters with a boiling point less than or equal to 154 ℃, including but not limited to one or more of ethyl acetate, methyl acetate, isopropyl acetate and ethyl lactate; the phosphate ester is selected from one or more of tripolyphosphate, tributyl phosphate, triphenyl phosphite, polyphosphoric acid and the like; the organic base is an organic heterocyclic basic compound, preferably selected from organic heterocyclic substances such as pyridine, thiophene, indole, piperazine, picoline and the like.
Further, the mass ratio of the phosphate ester, the organic base and the ester solvent can be 1-5: 3-5: 90-96, and preferably 2-5: 3-4: 91-95.
Further, the solid adding amount in the reflux washing process is 10-35 wt% of the total system, preferably 25-30 wt%; the refluxing time is 1-5 hours, preferably 2-3 hours; the filtration mode is common filtration, vacuum filtration, filter pressing, centrifugation and the like; the vacuum drying temperature is 70-140 ℃, and preferably 75-120 ℃. The vacuum drying pressure is-0.1 to-0.095 MPa.
The invention further relates to olive-shaped crystals of N-methyl-4-nitrophthalimide obtained by the above process.
The invention has the beneficial effects that:
1. avoids the heat accumulation in the low-temperature nitration process, can accelerate the reaction rate and improve the safety of the reaction process, and is shown in figure 1.
2. The product yield of the N-methyl-4-nitrophthalimide is improved.
3. Phosphate and organic heterocyclic alkaline compounds are used as crystal forming aids, which are beneficial to crystal forming, increase the product bulk density, facilitate the synthesis of downstream products and increase the yield of the downstream products, and refer to the attached figures 2 and 3.
Drawings
FIG. 1 is a RC1 calorimetric test chart of low-temperature nitration and high-temperature nitration of comparative example 1 and example 1, wherein (a) is an RC1 calorimetric test chart of comparative example 1, (b) is an RC1 calorimetric test chart of example 1, and (c) is a graphical illustration of each color curve of RC 1.
FIG. 2 is a graph comparing the crystal shapes of the conventional process and the process of the present invention, wherein (a) is the crystal shape of the product of example 1 in the form of olive and (b) is the crystal shape of the product of comparative example 1 in the form of irregular size.
FIG. 3 is an XRD spectrum of the crystal shapes obtained by the present method, wherein (a) is the crystal XRD spectrum of olive-shaped product of example 1, and (b) is the crystal shape XRD spectrum of irregular-sized product of comparative example 1.
Detailed Description
The present invention is further illustrated by the following examples, which are provided only for the purpose of illustration and are not intended to limit the scope of the present invention.
Example 1
161g N-methylphthalimide solid was added to 98 wt% of 300g of concentrated sulfuric acid with stirring turned on and the system was heated to 40 ℃ until the N-methylphthalimide was completely dissolved. Weighing 65g of 98 wt% fuming nitric acid, gradually adding the fuming nitric acid into the system through a dropping funnel, introducing cooling water into the system, cooling, removing heat, and keeping the temperature of the system at 40 ℃. After the addition of the nitric acid was completed, the temperature was maintained at 40 ℃ for 2.5 hours.
The reaction was cooled to room temperature and poured into 618g of an ice-water mixture with stirring to precipitate. After the product N-methyl-4-nitrophthalimide solid was filtered and washed with water to pH 7, the product was dried at 90 ℃ under atmospheric pressure.
Adding the dried product into a washing and purifying solvent, wherein the solvent comprises tributyl phosphate, pyridine and ethyl acetate in a ratio of 4: 92, and the content of N-methyl-4-nitrophthalimide in the system is 28%; heating and refluxing under stirring for 2.6 hours; cooling the system to normal temperature, filtering the solid, washing the solid with ethyl acetate once, and drying the solid at 80 ℃ under the pressure of-0.098 MPa to obtain the olive-shaped N-methyl-4-nitrophthalimide crystal. The yield thereof was found to be 93%. The bulk density is 0.60 to 0.65 g/mL.
Example 2
161g of N-methylphthalimide solid was added to 93 wt% of concentrated sulfuric acid with stirring turned on, and the system was heated to 40 ℃ until the N-methylphthalimide was completely dissolved. Weighing 71.44g of fuming nitric acid with the weight percent, gradually adding the fuming nitric acid into the system through a dropping funnel, introducing cooling water into the system to cool and remove heat, and keeping the temperature of the system at 45 ℃. After the addition of the nitric acid was completed, the temperature was maintained at 60 ℃ for 2 hours.
The reaction was cooled to room temperature and poured into 515g of an ice-water mixture with stirring to precipitate. After the product N-methyl-4-nitrophthalimide solid was filtered and washed with water to pH 7, the product was dried at 100 ℃ under atmospheric pressure.
Adding the dried product into a washing and purifying solvent, wherein the solvent comprises tripolyphosphate, thiophene and methyl acetate in a ratio of 1: 3: 96, and the content of N-methyl-4-nitrophthalimide in the system accounts for 25%; heating and refluxing under stirring for 1 hour; cooling the system to normal temperature, filtering the solid, washing the solid with methyl acetate once, and drying the solid at 70 ℃ under-0.099 MPa to obtain the olive-shaped N-methyl-4-nitrophthalimide crystal. The yield thereof was found to be 91.5%. The bulk density is 0.60 to 0.65 g/mL.
Example 3
161g N-methylphthalimide solid was added to 96 wt% of concentrated sulfuric acid 306g with stirring turned on and the system was heated to 30 ℃ until the N-methylphthalimide was completely dissolved. Weighing 66.3g of fuming nitric acid with the concentration of 95 wt%, gradually adding the fuming nitric acid into the system through a dropping funnel, introducing cooling water into the system, reducing the temperature, removing the heat, and keeping the temperature of the system at 30 ℃. After the addition of nitric acid was completed, the temperature was maintained at 30 ℃ for 3 hours.
The reaction was cooled to room temperature and poured into 824g of an ice-water mixture with stirring to precipitate. After the product N-methyl-4-nitrophthalimide solid was filtered and washed with water to pH 7, the product was dried at 80 ℃ under atmospheric pressure.
Adding the dried product into a washing and purifying solvent, wherein the solvent comprises triphenyl phosphite, indole and ethyl lactate in a ratio of 5: 90, and the content of N-methyl-4-nitrophthalimide in the system accounts for 35 percent; heating and refluxing under stirring for 2 hours; cooling the system to normal temperature, filtering the solid, washing the solid with ethyl lactate once, and drying the solid at 140 ℃ under-0.095 MPa to obtain the olive-shaped N-methyl-4-nitrophthalimide crystal. The yield thereof was found to be 94%. The bulk density is 0.60 to 0.65 g/mL.
Example 4
161g N-methylphthalimide solid was added to 360g of 98 wt% concentrated sulfuric acid with stirring turned on and the system was heated to 60 ℃ until the N-methylphthalimide was completely dissolved. Weighing 111g of fuming nitric acid with the concentration of 85 wt%, gradually adding the fuming nitric acid into the system through a dropping funnel, introducing cooling water into the system, reducing the temperature, removing the heat, and keeping the temperature of the system at 35 ℃. After the addition of nitric acid was completed, the temperature was maintained at 30 ℃ for 5 hours.
The reaction was cooled to ambient temperature and poured into 1030g of ice-water mixture with stirring to precipitate. After the product N-methyl-4-nitrophthalimide solid was filtered and washed with water to pH 7, the product was dried at 120 ℃ under atmospheric pressure.
Adding the dried product into a washing and purifying solvent, wherein the solvent comprises polyphosphoric acid, methylpyridine and isopropyl acetate which are 5: 4: 91, and the content of N-methyl-4-nitrophthalimide in the system accounts for 10%; heating and refluxing under stirring for 3 hours; cooling the system to normal temperature, filtering the solid, washing the solid with isopropyl acetate once, and drying the solid at the temperature of 75 ℃ under the pressure of-0.095 MPa to obtain the olive-shaped N-methyl-4-nitrophthalimide crystal. The yield thereof was found to be 84%. The bulk density is 0.60 to 0.65 g/mL.
Example 5
161g N-methylphthalimide solid was added to 98 wt% of 300g of concentrated sulfuric acid with stirring turned on and the system was heated to 35 ℃ until the N-methylphthalimide was completely dissolved. Weighing 65.6g of 98 wt% fuming nitric acid, gradually adding the fuming nitric acid into the system through a dropping funnel, introducing cooling water into the system, cooling, removing heat, and keeping the temperature of the system at 100 ℃. After the addition of nitric acid was completed, the temperature was maintained at 100 ℃ for 1.5 hours.
The reaction was cooled to room temperature and poured into 721g of an ice-water mixture with stirring to precipitate. After the product N-methyl-4-nitrophthalimide solid was filtered and washed with water to pH 7, the product was dried at 95 ℃ under atmospheric pressure.
Adding the dried product into a washing and purifying solvent, wherein the solvent comprises tributyl phosphate, piperazine and ethyl acetate in a ratio of 2: 3: 95, and the content of N-methyl-4-nitrophthalimide in the system is 30%; heating and refluxing under stirring for 5 hours; cooling the system to normal temperature, filtering the solid, washing the solid with ethyl acetate once, and drying the solid at 120 ℃ under-0.097 MPa to obtain the olive-shaped N-methyl-4-nitrophthalimide crystal. The yield thereof was found to be 94%. The bulk density is 0.60 to 0.65 g/mL.
Comparative example 1
161g N-methylphthalimide solid is added into 98 wt% concentrated sulfuric acid 300g with stirring started, the system is heated to 40 ℃ until N-methylphthalimide is completely dissolved, and the temperature of the system is reduced to below 10 ℃. Weighing 65g of 98 wt% fuming nitric acid, gradually adding the fuming nitric acid into the system through a dropping funnel, introducing cooling water into the system, cooling, removing heat, and keeping the temperature of the system at 10 ℃. After the addition of the nitric acid was completed, the temperature was maintained at 10 ℃ for 3 hours. Gradually heating to 40 ℃ by adopting a step heating mode, and reacting for 3 hours.
The reaction was cooled to room temperature and poured into 618g of an ice-water mixture with stirring to precipitate. And filtering the product N-methyl-4-nitrophthalimide solid, washing the product with water until the pH value is 7, and drying the product at 90 ℃ under normal pressure to obtain N-methyl-4-nitrophthalimide crystals with irregular particle sizes. The yield thereof was found to be 80%. The bulk density is 0.35 to 0.40 g/mL.
Application example 1
After introducing high-purity nitrogen into a 1000ML four-neck flask, stirring was started, and 8.0g of sodium hydroxide, 22.8g of bisphenol A and 570g of o-xylene were added thereto, and the mixture was heated to a reflux temperature of 144 ℃ and reacted for 4 hours. And then gradually discharging water in the water separator out of the reaction system, evaporating all o-xylene in the reaction system out of the system when water drops cannot be seen in the water separator, cooling to below 100 ℃, and keeping nitrogen smooth all the time.
41.2g of N-methyl-4-nitrophthalimide prepared as described in example 1 was dissolved in N, N-dimethylacetamide under heating, the solution was added rapidly to the reaction system, the reaction system was heated to 155 ℃ and allowed to react for 6 hours, and then cooled to room temperature.
Adding the reacted solution into ethanol for precipitation and filtration, washing the solution with the ethanol, washing the ethanol and the salt with the water, and obtaining white N-methyl-N ' -methyl-3, 3 ', 4, 4 ' -bisphenol A diether bis phthalimide solid with the molar yield of 94.2 percent at the normal pressure of 100 ℃.
Application comparative example 1
The solid N-methyl-4-nitrophthalimide prepared by the method of comparative example 1 was used for the synthesis of N-methyl-N ' -methyl-3, 3 ', 4, 4 ' -bisphenol A diether bisphthalimide in the same manner as in application example 1. The yield of the obtained N-methyl-N ' -methyl-3, 3 ', 4, 4 ' -bisphenol A diether bis phthalimide product is 75%.
Claims (17)
1. A preparation method of olive-shaped N-methyl-4-nitrophthalimide crystals comprises the following steps:
a) reacting N-methylphthalimide with fuming nitric acid in a concentrated sulfuric acid system to prepare a concentrated sulfuric acid solution of N-methyl-4-nitrophthalimide;
b) pouring a concentrated sulfuric acid solution of N-methyl-4-nitrophthalimide into low-temperature water, stirring, separating out N-methyl-4-nitrophthalimide solid, washing the solid with water until filtrate is neutral, and drying;
c) and putting the dried N-methyl-4-nitrophthalimide solid into an ester solvent for dissolving phosphate and organic base, refluxing and cooling, filtering and drying the mixture to obtain olive-shaped N-methyl-4-nitrophthalimide crystals, wherein the organic base is selected from organic heterocyclic alkaline compounds, and the mass ratio of the phosphate to the organic base to the ester solvent is 1-5: 3-5: 90-96.
2. The process of claim 1, wherein in step a), the concentrated sulfuric acid has a concentration of 93 to 98 wt% and the fuming nitric acid has a concentration of 85 to 98 wt%.
3. The process of claim 2 wherein in step a), the fuming nitric acid has a concentration of 95 to 98 wt%.
4. The process according to any one of claims 1 to 3, wherein the mass ratio of N-methyl-4-nitrophthalimide to concentrated sulfuric acid and fuming nitric acid is from 1: 2 to 5: 0.2 to 3.
5. The method according to claim 4, wherein the mass ratio of N-methyl-4-nitrophthalimide to concentrated sulfuric acid and fuming nitric acid is 1: 3 to 3.6: 0.3 to 1.5.
6. The method according to claim 5, wherein the mass ratio of N-methyl-4-nitrophthalimide to concentrated sulfuric acid and fuming nitric acid is 1: 3 to 3.1: 0.4 to 1.1.
7. The method according to any one of claims 1 to 3, wherein in the step a), the solid N-methyl-4-nitrophthalimide is added into concentrated sulfuric acid with stirring started, the mixture is gradually heated to be dissolved, fuming nitric acid is gradually added into the reaction system dropwise, the temperature is reduced to normal temperature after the reaction is carried out for a period of time, and the temperature for heating and dissolving the N-methylphthalimide is selected from 30-60 ℃; the system temperature controlled during the dropwise addition of the nitric acid is 30-100 ℃; the reaction time is 1.5-5 hours.
8. The method according to claim 7, wherein in the step a), the temperature for heating and dissolving the N-methylphthalimide is selected from 35-45 ℃; the reaction time is 2-3 hours.
9. The method according to any one of claims 1 to 3, wherein in step b), the low-temperature water is selected from an ice-water mixture and water at 0 to 15 ℃; and/or
The mass of the low-temperature water is 2.5-5 times of the theoretical yield of the N-methyl-4-nitrophthalimide; and/or
The pH value of the washed filtrate is neutral and is 6-8; and/or
The drying temperature is 80-120 ℃.
10. The method according to claim 9, wherein in step b), the low-temperature water is selected from ice-water mixture; and/or
The mass of the low-temperature water is 3-4 times of the theoretical yield of the N-methyl-4-nitrophthalimide; and/or
The drying temperature is 90-100 ℃.
11. The process according to any one of claims 1 to 3, wherein in step c) the reflux washed ester solvent is selected from esters having a boiling point of 154 ℃ or less; and/or
The phosphate is selected from one or more of tripolyphosphate, tributyl phosphate, triphenyl phosphite and polyphosphoric acid; and the organic base is an organic heterocyclic basic compound.
12. The method according to claim 11, wherein in step c), the refluxing and washing ester solvent is selected from one or more of ethyl acetate, methyl acetate, isopropyl acetate, ethyl lactate; and/or
The organic base is selected from one or more of pyridine, thiophene, indole, piperazine and picoline.
13. The method according to any one of claims 1 to 3, wherein the mass ratio of the phosphate ester, the organic base and the ester solvent is 2 to 5: 3 to 4: 91 to 95.
14. The method according to any one of claims 1 to 3, wherein the amount of the solid added in the reflux washing process is 10 to 35 wt% of the total system, and the reflux time is 1 to 5 hours.
15. The method according to claim 14, wherein the solid is added in an amount of 25 to 30 wt% of the total system during the reflux washing, and the reflux time is 2 to 3 hours.
16. The method according to any one of claims 1 to 3, wherein the filtration is one or more of ordinary filtration, vacuum filtration, filter pressing and centrifugation; and/or
The vacuum drying temperature is 70-140 ℃; the vacuum drying pressure is-0.1 to-0.095 MPa.
17. The method according to claim 16, wherein the vacuum drying temperature is 75-120 ℃.
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Non-Patent Citations (4)
| Title |
|---|
| 4-硝基-N-甲基-邻苯二甲酰亚胺合成新工艺;郑凯，等;《石油化工》;20041231;第33卷(第2期);145-148 * |
| 4-硝基-N-甲基-邻苯二甲酰亚胺的合成新工艺研究;郑凯，等;《江苏化工》;20031231;第31卷(第6期);39-41 * |
| 4-硝基-N-甲基邻苯二甲酰亚胺的合成研究;李亚林，等;《廊坊师范学院学报( 自然科学版)》;20170331;第17卷(第1期);69-73 * |
| 4-硝基邻苯二甲酰亚胺的合成;项斌，等;《浙江工业大学学报》;20031031;第31卷(第5期);512-523 * |
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