WO2018124453A1 - Method for producing n-substituted maleimide using solid acid catalyst - Google Patents

Abstract

The present invention relates to a method for producing an N-substituted maleimide using a heterogeneous solid acid catalyst. Specifically, the purpose of the present invention is to provide a method for producing an N-substituted maleimide, wherein, by using a zirconium(IV) hydrogenphosphate solid acid catalyst as a catalyst of an N-substituted maleimide synthesis reaction, the loss of the catalyst is minimized, the separation and recovery processes of the catalyst are simplified, the catalyst can be completely regenerated through washing or firing when the activity of the separated and recovered catalyst is reduced, there is no restriction on the choice of washing solvent, and the yield of N-substituted maleimide synthesis is high.

Description

Method for preparing N-substituted maleimide using solid acid catalyst

Citation with Related Applications

This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0181021 dated December 28, 2016 and Korean Patent Application No. 10-2017-0133529 dated October 13, 2017. All content disclosed in the literature is included as part of this specification.

Technical Field

The present invention relates to a method for synthesizing N-substituted maleimide using zirconium (IV) hydrogenphosphate as a solid acid catalyst.

The maleimide compound is a compound useful as a raw material for water support fees, pharmaceutical pesticides, and the like, and in particular, styrene resins such as ABS resins, AS resins, AB resins, ACS resins, AES resins, AAS resins, polyvinyl chloride resins, In order to improve heat resistance of polymethyl methacrylate resins and phenol resins, they are frequently used as one of copolymerization components. Among them, N-phenyl maleimide (hereinafter also referred to as PMI) is excellent in terms of reactivity and heat resistance, and is particularly widely used.

About the manufacturing method of a maleimide compound, 1) the method obtained by dehydrating maleic anhydride (henceforth MAH) and primary amines in one step, 2) maleamine from maleic anhydride and primary amines Many methods conventionally, such as the method of producing | generating an acid and obtaining it by the ring-closure imidation reaction of this maleamic acid, and 3) the method obtained by the ring-ring imidation reaction of corresponding maleamic acid monoesters. This is known.

Among these methods, in the method of 1) obtaining in one step from maleic anhydride and primary amines, there is still a problem that the yield is low and the productivity is poor, and 3) the method of obtaining from maleamic acid monoesters, the ring-ring imidization Since the alcohol which arises by reaction remains in a product, etc. remain, industrially, the method of obtaining by 2) the dehydration ring closure imidation reaction of maleamic acid is generally performed.

In addition, the primary amines at the time of manufacturing N-phenyl maleimide are aniline (henceforth ANL), and maleamic acid is N-phenyl maleamic acid (henceforth PMA).

Most of the catalysts used in the conventional method of synthesizing N-phenyl maleimide of 2) used a liquid catalyst which is a homogeneous system directly or a catalyst having a homogeneous active component supported on a carrier. However, in this case, the loss of the active ingredient may occur due to water, a by-product generated during the synthesis of N-phenyl maleimide, it is difficult to supplement and regenerate the lost active ingredient, it is used to separate the catalyst There is a problem in that the separation process of the catalyst is complicated, such as the limitation of the solvent, the generation of a large amount of waste water in the process of removing residual catalyst and impurities, and the input of energy according to the cooling and heating.

In order to solve the above problems, the inventors of the present invention have solved the above problems when using zirconium hydrogenphosphate as a solid acid catalyst in the method for preparing N-phenylmaleimide of 2). It has been found that the present invention has been completed.

[Preceding technical literature]

(Patent Document 1) Republic of Korea Patent Publication No. 10-1051543 (Registered July 18, 2011)

The problem to be solved of the present invention is to use a zirconium hydrogen phosphate (Zirconium (IV) hydrogenphosphate) solid acid catalyst as a catalyst for the N-substituted maleimide synthesis reaction, thereby minimizing the loss of the catalyst to supplement the catalyst during the synthesis reaction It is to provide a method for producing unnecessary N-substituted maleimide.

In addition, another problem to be solved of the present invention is that the solid acid catalyst can be separated and recovered through simple filtration, so that the separation and recovery process is simplified, and the activity of the separated and recovered catalyst is reduced, washed or calcined. Through the complete regeneration of the catalyst, there is provided a method for producing N-substituted maleimide without limitation of the solvent that can be used in the catalyst washing process.

In addition, another object of the present invention is to provide a method for producing N-substituted maleimide having high yield of N-substituted maleimide.

The present invention is to solve the above problems,

In the manufacturing method of N-substituted maleimide,

1) adding maleic anhydride and a primary amine in the presence of an organic solvent and a catalyst to synthesize N-substituted maleimides; And

2) separating the catalyst from the solution containing the N-substituted maleimide,

The catalyst provides a method for producing N-substituted maleimide, characterized in that the zirconium hydrogen phosphate (Zirconium (IV) hydrogenphosphate) solid acid catalyst.

N-substituted maleimide production method of the present invention by using a zirconium hydrogen phosphate solid acid catalyst during the synthesis reaction of N-substituted maleimide, there is an effect that unnecessary replacement of the catalyst during the synthesis reaction to minimize the loss of the catalyst.

In addition, the solid acid catalyst is capable of separating and recovering the catalyst through simple filtration, and thus, the separation and recovery process of the catalyst is simple, and the catalyst can be completely regenerated by washing or firing. There is an effect that the solvent can be used without any kind.

In addition, the zirconium hydrogen phosphate solid acid catalyst has an effect of high N-substituted maleimide synthesis yield.

The following drawings, which are attached to this specification, illustrate specific embodiments of the present invention, and together with the contents of the present invention, the present invention serves to further understand the technical spirit of the present invention. It should not be construed as limited.

1 is a flowchart showing the procedure of the N-substituted maleimide production method of the present invention.

2 is a flowchart showing the procedure of a conventional method for producing N-substituted maleimide.

Hereinafter, the present invention will be described in more detail to aid in understanding the present invention. At this time, the terms or words used in the present specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors appropriately define the concept of terms in order to explain their own invention in the best way. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that it can.

The present invention

In the manufacturing method of N-substituted maleimide,

1) adding maleic anhydride and a primary amine in the presence of an organic solvent and a catalyst to synthesize N-substituted maleimides; And

2) separating the catalyst from the solution containing the N-substituted maleimide,

The catalyst provides a method for producing N-substituted maleimide, characterized in that the zirconium hydrogen phosphate (Zirconium (IV) hydrogenphosphate) solid acid catalyst.

Hereinafter, the method for preparing N-substituted maleimide compounds of the present invention will be described in detail with reference to FIG. 1.

Step 1)

Step 1) according to an embodiment of the present invention is a step for synthesizing N-substituted maleimide, by introducing maleic anhydride and primary amine in the presence of an organic solvent and a catalyst to form N-substituted maleimide It is characterized by synthesizing.

About the manufacturing method of a maleimide compound, 1) the method obtained by dehydrating maleic anhydride and a primary amine in one step, 2) maleic anhydride is produced | generated from maleic anhydride and a primary amine, and this malea The method obtained by the dehydration ring closure imidation reaction of a hydrochloric acid, 3) The method obtained by ring closure imidation reaction of the corresponding maleic acid monoester, etc. are mentioned.

However, in 1) the method of obtaining from a maleic anhydride and a primary amine by one step, there is still a problem that productivity is low because a yield is still low, and 3) the method obtained from a maleamic acid monoester is used for a ring-ring imidation reaction. There is a problem in that the alcohol generated by the residue remaining in the product, etc., the method for producing N-substituted maleimide of the present invention is carried out to synthesize N-substituted maleimide by 2) dehydration ring closure imidization reaction of maleamic acid The form is explained in full detail.

In the N-substituted maleimide production method of the present invention, maleic anhydride and primary amine are heated to acylate in one step to obtain N-substituted maleamic acid as an intermediate, and the N is substituted on the surface of the catalyst in two steps. N-substituted maleimide can be synthesize | combined by the method of the dehydration ring-closure imidation reaction of -substituted maleamic acid.

In addition, in the step of obtaining N-phenyl maleamic acid from the maleic anhydride and aniline, maleic anhydride or aniline may be used as it is, but is preferably used in the form of a solution dissolved in an organic solvent. . On the other hand, when using maleic anhydride or aniline in the form of the solution which melt | dissolved in the organic solvent, the following dehydration ring closure imidation reaction of N-phenyl maleamic acid can be performed in a solution (organic solvent) as it is.

The organic solvent used in the present invention is insoluble or immiscible in water, inert to the reaction, and capable of releasing water generated by the dehydration ring closure reaction of N-substituted maleamic acid through the azeotropic distillation. Do not participate.

 In addition, it is suitable that the boiling point is at least 50 ° C. or higher for the smooth progress of the reaction, and the boiling point is lower than 170 ° C. for the stability of the resulting N-substituted maleimide. Examples of suitable organic solvents for this reaction include benzene, toluene, xylene, o-xylene, ethylbenzene, isopropylbenzene, cumene, mesitylene, tert-butylbenzene, pseudocumene, trimethylhexane, octane, tetra Chloroethane, nonane, chlorobenzene, ethylcyclohexane, m-dichlorobenzene, sec-butylbenzene, p-dichlorobenzene, decane, p-cymene, o-dichlorobenzene, butylbenzene, decahydronaphthalene, tetrahydronaphthalene, dode Cane, naphthalene, cyclohexylbenzene, and the like, and the organic solvent may be used alone or in the form of a mixture of two or more thereof.

The amount of the organic solvent to be used is not particularly limited. However, the amount of the organic solvent is about 1 to 20 times (by weight) more preferably about 1 to 20 times the amount of the primary amine to be used as a raw material, in order to satisfy the economic conditions while smoothly carrying out the reaction. The range of 2 to 10 times (by weight) is appropriate. If the amount of the organic solvent is less than 2 times, there is a problem in that the yield is not easy to effectively remove the water produced through the dehydration ring-closure reaction of the N-substituted maleamic acid from the reaction system, if the amount exceeds 10 times synthesized In the process of separating the organic solvent from the N-substituted maleimide solution, excessive energy is consumed, which is not preferable from an economic point of view.

In addition, the organic solvent should be determined in consideration of environmental factors and solubility, price and ease of handling of N-substituted maleimide, and moreover, a solvent suitable for easy removal and reuse after completion of the reaction should be selected. Here, maleic anhydride and primary amine may be dissolved in the same organic solvent or in another organic solvent, but are preferably dissolved in the same organic solvent.

In addition, the concentration of maleic anhydride or primary amine in the case of using maleic anhydride or primary amine in the form of a solution dissolved in an organic solvent is not particularly limited as long as it can dissolve maleic anhydride or primary amine. Do not. Specifically, it is preferable that 0-500 g of organic solvents, more preferably 10-200 g are added and melt | dissolved with respect to 100 g of maleic anhydride. Moreover, it is preferable that 0-500 g of organic solvents, More preferably, 5-200 g are added and melt | dissolved with respect to 100 g of primary amines.

In one embodiment of the present invention, the primary amine is a saturated or unsaturated alkylamine having 1 to 20 carbon atoms, cycloalkylamine having 5 to 20 carbon atoms, cycloalkylamine having 6 to 20 carbon atoms or 6 to 20 carbon atoms One kind of primary amine selected from among aromatic alkylamines may be used, specifically, methyl amine, ethyl amine, n-propyl amine, isopropyl amine, n-butyl amine, sec-butyl amine, iso-butyl amine , at least one selected from the group consisting of tert-butylamine, n-hexyl amine, n-octyl amine, n-decyl amine, n-dodecyl amine, cyclohexyl amine and aniline can be used. Aniline can be used as the primary amine to synthesize phenyl maleimide.

In the present invention, the amount of maleic anhydride is preferably used in an amount of 1.0 to 1.3 molar ratio relative to the primary amine used in the synthesis of N-substituted maleimides. When maleic anhydride is used at less than 1.0 molar ratio, problems of yield reduction and by-products increase. When the maleic anhydride is used at 1.3 molar ratio or higher, unreacted maleic anhydride remains excessive after N-substituted maleimide synthesis. It is not preferable in terms of.

On the other hand, most of the catalysts used in the conventional N-substituted maleimide synthesis method used a liquid catalyst which is a homogeneous system directly or a supported catalyst carrying a homogeneous active component in the carrier. However, in the case of using the homogeneous liquid catalyst, the loss of the catalyst may occur in the process of separating the product from the catalyst through layer separation due to the polarity difference after the completion of the synthesis reaction, and in the case of using the supported catalyst, N-substituted maleimide Loss of the active ingredient was generated by water, a by-product generated during the synthesis, and it was necessary to continuously replenish the lost part of the active ingredient, and the supplementation of the active ingredient was also possible after separating and drying the supported catalyst. There is a problem that the process is complicated and the supplementation of the active ingredient is not easy.

Unlike the conventional manufacturing method, the N-substituted maleimide production method of the present invention synthesizes N-substituted maleimides using a heterogeneous solid acid catalyst rather than a homogeneous liquid catalyst or a supported catalyst. It is characterized by being able to solve the problem. In the present invention, the homogeneous system means that the reactants of the N-substituted maleimide synthesis reaction and the catalyst have the same phase, and the heterogeneous system means that the reactants and the catalyst have different states.

More specifically, the heterogeneous solid acid catalyst used in the present invention is characterized in that the zirconium hydrogen phosphate (Zirconium (IV) hydrogenphosphate).

Zirconium hydrogenphosphate (Zirconium (IV) hydrogenphosphate, Zr (HPO ₄ ) ₂ ) is an acidic, inorganic cation exchange material with a layered structure, with high thermal and chemical stability, solid ion conductivity, resistance to ionizing radiation, and To introduce different types of molecules of different sizes into their layers. The zirconium hydrogen phosphate may exist in a variety of states having a variety of interlayer space and crystal structure, the most widely known zirconium hydrogen phosphate is alpha type of Zr (HPO ₄ ) _{2 ·} H ₂ O and Zr (PO ₄ ) (H ₂ PO ₄ ) · 2H ₂ O. The zirconium hydrogen phosphate may be utilized in various fields such as drug delivery, catalysis, nanocomposites, nuclear waste management or clinical dialysis machine.

In the case of the present invention, the zirconium hydrogen phosphate used as the solid acid catalyst is an amorphous zirconium hydrogen phosphate rather than the crystalline structures of the alpha type and the gamma type, and the degree of hydration may vary depending on the reaction conditions. Can be displayed.

[Formula 1]

Zr _x (H _a PO _b ) _c

(In Formula 1, 0.5≤x≤1.5, 0≤a≤8, 0≤b≤8, 1≤c≤4.)

As described above, the method for preparing N-substituted maleimide compounds of the present invention can minimize the possibility of loss of the catalyst by using a heterogeneous solid acid catalyst having a different state from the reactant of the N-substituted maleimide synthesis reaction. Among them, the yield of N-substituted maleimides is high by using zirconium hydrogen phosphate.

Specifically, the catalyst of the present invention is a solid in a state different from the reactants, and the loss of the active component by water, which is a by-product generated during the synthesis of N-substituted maleimide, and the loss of the catalyst in the phase separation process after completion of the synthesis reaction. The zirconium hydrogen phosphate used in the present invention is structurally very stable, and since the reactivity with water is low, it is not necessary to replenish and regenerate the catalyst during the reaction, thereby preparing N-substituted maleimides. The process also has the effect of being simplified.

In addition, the zirconium hydrogen phosphate of the present invention has a higher yield of N-substituted maleimide synthesis than other solid acid catalysts, and specifically, when zirconium hydrogen phosphate is added in an amount of 0.06 weight or more relative to the input reaction solvent, N-substituted male The yield of mids synthesis can be made 70% or more.

On the other hand, the heterogeneous solid acid catalyst of the present invention should be added in an appropriate amount from the viewpoint of process operation and cost, specifically, it is added in a weight ratio of 0.01 to 1.0 weight ratio, more specifically 0.05 to 0.5 with respect to the input reaction solvent. desirable.

If the input amount is less than 0.01 weight ratio, there is a problem in that the total reaction time is low because the ratio of N-substituted maleamic acid converted per unit time is low, and if it exceeds 1.0 weight ratio, the reaction medium is generated according to the production of N-substituted maleamic acid as an intermediate product. Agitation due to increased solids may not be smooth.

In some cases, the metal-containing compound and the stabilizer may be coexisted in the reaction system and reacted. The metal-containing compound used at this time is not particularly limited, but at least one metal oxide, acetate, maleate, succinate salt selected from the group consisting of zinc, chromium, palladium, cobalt, nickel, iron and aluminum. of succinic acid, nitrates, phosphates, chlorides and sulfates. Of these, zinc acetate is particularly effective. The amount of these used is 0.005 to 0.5 mol%, preferably 0.01 to 0.1 mol%, as a metal, based on maleic anhydride and / or primary amine as a raw material.

In addition, as a stabilizer, methoxybenzoquinone, p-methoxyphenol, phenothiazine, hydroquinone, alkylated diphenyl amines, methylene blue, tert-butyl catechol, tert-butylhydroquinone, dimethyldithiocarba Mate zinc, dimethyldithiocarbamate, copper dibutyldithiocarbamic acid, copper salicylate, thiodipropionic acid esters, mercaptobenzimidazole, triphenyl phosphite, alkyl phenols, alkyl bisphenols, and the like are used. The effect of these stabilizers plays a role of making the N-substituted maleimide produced by the dehydration ring closure imidization reaction stably exist without deterioration even at a high temperature of the imidization reaction. Although the addition amount is not specifically limited, 0.001 to 0.5 mol% can be used with respect to maleic anhydride and / or primary amine which are raw materials. Here, if it is such an addition amount, the said stabilizing effect can fully be exhibited and the problem mixed in a product can also be avoided.

In the method for producing N-substituted maleimide of the present invention, the reaction temperature of the N-substituted maleimide of step 1) is generally 50 to 200 ° C, more preferably 100 to 140 ° C. When the synthesis reaction temperature is less than 50 ℃, a problem that the yield is lowered, when the temperature is 200 ℃ or more, the polymerization of N-substituted maleimide synthesized by side reaction is inhibited, the purity and yield of the synthesized N-substituted maleimide This deterioration problem occurs.

There is no particular limitation on the reaction pressure in the present invention, and it can be selected in a wide range from reduced pressure, atmospheric pressure and pressure. The reaction may vary depending on conditions such as the type of solvent, the amount of raw materials, the amount of catalyst and the reaction temperature, but is generally about 1 to 16 hours, more preferably within 1 to 10 hours.

Under such reaction conditions, the dehydration ring closure imidation reaction of the N-substituted maleamic acid proceeds efficiently, and the N-substituted maleimide can be efficiently obtained.

Step 2)

Step 2) according to an embodiment of the present invention is a separation and recovery step for reusing the catalyst, characterized in that the catalyst is separated and recovered from a solution containing N-substituted maleimide.

In the conventional production method using a homogeneous catalyst or a supported catalyst, a solution layer in which N-substituted maleimide is dissolved is first separated from the catalyst layer to separate layers, and secondly, a catalyst remaining in the product through a washing solvent. The catalyst was separated and recovered by removing and removing impurities. However, in this case, the separation of the homogeneous catalyst is not easy, and the supported catalyst also loses the active ingredient in the carrier, and a large amount of wastewater is generated, making the separation and recovery process difficult and complicated.

In addition, since the separation of the layers is not easy at high temperatures such as the reaction temperature of the N-substituted maleimide synthesis reaction, a cooling process is performed to separate the layers, and a reheating process is performed to reuse the catalyst. There was a problem in that other additional energy was required for reheating.

However, the catalyst used in the N-substituted maleimide production method of the present invention uses a zirconium hydrogen phosphate, which is a structural acid and a chemically stable solid acid as a solid acid catalyst, so that cooling and reheating processes are unnecessary, thereby adding energy. No input is required and the catalyst is filtered by simple filtration even at a temperature from the lowest temperature at which the product does not precipitate as a solid on the solution containing the product to the break point of the solution containing the product, more specifically at a high temperature of 70 to 160 ° C. Since separation and recovery of the catalyst are possible, there is an effect of simplifying the separation and recovery of the catalyst.

On the other hand, when the separated and recovered catalyst is reused in the next cycle of reaction, the activity of the catalyst is reduced due to the loss of the active ingredient or damage to the active ingredient by impurities, so that the reaction yield also generally decreases proportionally.

In the conventional manufacturing method, the washing solvent that can be used to wash the impurities in the washing or calcining process for regenerating the activity of the catalyst has a limitation, and the catalyst can not be regenerated through the simple calcining process. There was a limit to give.

However, in the case of the present invention, a heterogeneous solid acid catalyst is used as a catalyst, and when the activity of the separated and recovered catalyst is partially reduced, the catalyst is maintained while the stability of the catalyst is maintained by washing with a washing solvent without any kind. It is possible to regenerate, and when the catalyst is completely inactive because the activity is completely reduced, there is a characteristic that the catalyst can be easily regenerated through a calcination process.

The washing solvent that can be used in the washing process can be used without limitation, a polar solvent, specifically, at least one polar solvent selected from the group consisting of water, acetone, sulfoxide series and cyclic polar organic solvent containing oxygen Can be used.

In the method for preparing N-substituted maleimide compounds of the present invention, the reactant is stored by mixing the catalyst which has been separated, recovered and regenerated with N-substituted maleimide compounds mixed with an organic solvent of the same type as used in the synthesis reaction to ensure fluidity. It can be transferred to a tank or synthesis reactor for reuse.

On the other hand, with respect to the reuse of the washing solvent, in the case of a supported catalyst carrying a conventional phosphoric acid component (active ingredient) when the phosphoric acid component is dissolved in the washing solvent, such as impurities in the washing solvent, when put into the distillation process to recycle the washing solvent, Reuse of the distillation process by the phosphoric acid component at high temperature is not possible to reuse, but the N-substituted maleimide production method of the present invention uses a solid acid catalyst as a catalyst, so the washing solvent of the present invention is also transferred to the distillation process. There is an additional advantage that can be reused.

As described above, the method for preparing N-substituted maleimide compounds of the present invention uses a heterogeneous zirconium hydrogenphosphate solid acid catalyst as a catalyst, thereby minimizing the loss of the catalyst. Separation and recovery of catalysts, including the limitation of solvents that can be used to separate catalysts generated in the production process, the generation of large amounts of waste water in the removal of residual catalysts and impurities, and the need for energy input for cooling and reheating, and The regeneration process can solve complex problems.

Example  One

In a 100 mL reactor with a stirrer, a thermometer, a water separator and a cooler, 20 ml of o-xylene, 2.5 g of aniline and 2.9 g of maleic anhydride, zirconium (H) hydrogenphosphate solid dissolved at 80 ° C as a solvent After the addition of 1.249 g of acid catalyst, the temperature of the reaction system was raised to 125 ° C to synthesize N-phenyl maleimide. Water generated by the dehydration ring closure reaction was removed out of the reaction system with o-xylene through azeotropic distillation. The o-xylene removed from the reaction system was further administered for 4 hours while being re-administered into the reaction system. After completion of the synthesis reaction, the supported catalyst was separated by filtration to recover an N-phenyl maleimide o-xylene solution. The recovered N-phenyl maleimide o-xylene solution was heated to 80 ° C. under 10 mmHg reduced pressure, and o-xylene was removed by distillation under reduced pressure to prepare N-phenyl maleimide.

Example  2

N-phenyl maleimide was prepared in the same manner as in Example 1, except that 0.8 g of the zirconium (IV) hydrogenphosphate solid acid catalyst was added in Example 1.

Example  3

N-phenyl maleimide was prepared in the same manner as in Example 1 except that 0.6 g of a Zirconium (IV) hydrogenphosphate solid acid catalyst was added in Example 1.

Comparative example  1 to 10

N-phenyl maleimide was prepared in the same manner as in Example 1, except that the solid acid catalyst described in Table 1 was used instead of the zirconium hydrogen phosphate solid acid catalyst in Example 1.

Experimental Example

After the completion of the N-phenyl maleimide synthesis reaction of Example 1 and Comparative Examples 1 to 10, the resulting solution was collected and analyzed by liquid chromatography (LC) to yield N-phenyl maleimide (PMI), ANL (aniline). Standard selectivity, and the content of APSI (2-Anilino-N-Phenyl Succinimide) and other ingredients (others) as impurities are shown in Table 1 below.

* PMI yield = (aniline conversion) x (PMI selectivity on product)

* Selectivity based on ANL = (moles of PMI on product) / (moles of converted ANL)

	Reaction conditions		PMI yield (%)	Selectivity based on ANL (% molar)	APSI (mol%)	Others (% mall)
	catalyst	line
Example 1	ZrP (Zirconium phosphate)	Phosphate Series	77.2	77.2	2.9	19.9
Example 2			38.9	38.9	0.7	58.63
Example 3			15.8	15.8	0.36	83.85
Comparative Example 1	SnPO (tin phosphate)		7.40	7.42	0.67	91.92
Comparative Example 2	BPO 4 (Boron phosphate)		0.04	0.04	0.00	99.96
Comparative Example 3	FePO 4		0.02	0.02	0.28	99.70
Comparative Example 4	B-Zeolite (cp811c-300)	Zeolite series	3.23	3.23	0.25	96.52
Comparative Example 5	Y-Zeolite (CBA300)		1.75	1.88	0.51	97.61
Comparative Example 6	Y-Zeolite (CBA500)		1.52	1.55	1.42	97.04
Comparative Example 7	ZSM-5		0.69	0.69	0.89	98.42
Comparative Example 8	CaSO 4	Sulfate Series	0.07	0.07	0.20	99.73
Comparative Example 9	MnSO 4		0.02	0.02	0.05	99.93
Comparative Example 10	Amberlite IR120H (acidic cation exchange resin)	Ion Exchange Resin Series	4.51	4.51	0.00	95.49

As shown in Table 1, when comparing Examples 1 to 3 and Comparative Examples 1 to 10 of the present invention, Comparative Examples 1 to 10 are the same as Examples 1 to 3 solid acid catalyst or a catalyst of the Phosphate series Even if using the N-phenyl maleimide (PMI) yield or ANL (aniline) based selectivity is not confirmed that high.

On the contrary, Examples 1 to 3 using the zirconium hydrogen phosphate solid acid catalyst showed that the N-phenyl maleimide (PMI) yield and the ANL (aniline) standard Selectivity were excellent. Specifically, Example 1, in which the same amount as the catalyst added in Comparative Example, was added, the synthesis efficiency was remarkably superior to Comparative Example, and in the case of Examples 2 and 3 in which only about 50 to 60 wt% of the catalyst added in the Comparative Example was added, It was confirmed that the synthesis efficiency is superior to the example.

Thus, when using a zirconium (IV) hydrogenphosphate solid acid catalyst as a catalyst for the N-substituted maleimide synthesis reaction, the loss of the catalyst is minimized, the catalyst separation and recovery process is simplified, and the separation and When the activity of the recovered catalyst is reduced, the catalyst can be completely regenerated by washing or calcining, and the process without restriction on the selection of the washing solvent has a simple effect, and furthermore, the synthesis yield is excellent. there was.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims (11)

1. In the manufacturing method of N-substituted maleimide,

   1) adding maleic anhydride and a primary amine in the presence of an organic solvent and a catalyst to synthesize N-substituted maleimides; And

   2) separating the catalyst from the solution containing the N-substituted maleimide,

   The catalyst is a zirconium hydrogen phosphate (Zirconium (IV) hydrogenphosphate) solid acid catalyst, characterized in that the N-substituted maleimide production method.
2. The method of claim 1,

   The zirconium hydrogen phosphate is N-substituted maleimide production method, characterized in that the amorphous.
3. The method of claim 1,

   The zirconium hydrogen phosphate is N-substituted maleimide production method characterized in that represented by the formula (1).

   [Formula 1]

   Zr _x (H _a PO _b ) _c

   (In Formula 1, 0.5≤x≤1.5, 0≤a≤8, 0≤b≤8, 1≤c≤4.)
4. The method of claim 1,

   The catalyst is N-substituted maleimide production method characterized in that the addition of a weight ratio of 0.01 to 1.0 with respect to the input reaction solvent.
5. The method of claim 1,

   Separation of the catalyst is N-substituted maleimide production method, characterized in that carried out by high temperature filtration step of 70 to 160 ℃.
6. The method of claim 1,

   N-substituted maleimide production method further comprising the step of regenerating the catalyst by washing or calcining the separated catalyst.
7. The method of claim 6,

   The washing of the catalyst is a method for producing N-substituted maleimide, characterized in that using at least one polar solvent selected from the group consisting of cyclic polar organic solvent containing water, acetone, sulfoxide series and oxygen.
8. The method of claim 6,

   N-substituted maleimide production method, characterized in that for reuse the regenerated catalyst.
9. The method of claim 1,

   The organic solvent is benzene, toluene, xylene, o-xylene, ethylbenzene, isopropylbenzene, cumene, mesitylene, tert-butylbenzene, pseudocumene, trimethylhexane, octane, tetrachloroethane, nonane, Chlorobenzene, ethylcyclohexane, m-dichlorobenzene, sec-butylbenzene, p-dichlorobenzene, decane, p-cymene, o-dichlorobenzene, butylbenzene, decahydronaphthalene, tetrahydronaphthalene, dodecane, naphthalene and cyclo N-substituted maleimide production method characterized in that at least one member selected from the group consisting of hexylbenzene.
10. The method of claim 1,

    The primary amines are methyl amine, ethyl amine, n-propyl amine, isopropyl amine, n-butyl amine, sec-butyl amine, iso-butyl amine, tert-butylamine, n-hexyl amine, n-octyl amine, N-substituted maleimide production method characterized in that at least one member selected from the group consisting of n-decyl amine, n-dodecyl amine, cyclohexyl amine and aniline.
11. The method of claim 1,

    The N-substituted maleimides include N-alkyl maleimides such as N-methyl maleimide, N-ethyl maleimide, N-hexyl maleimide, N-octyl maleimide, and N-dodecyl maleimide; N-benzylmaleimide; N-cycloalkyl maleimide, such as N-cyclohexyl maleimide; N-phenyl maleimide; And N-nitrophenyl maleimide, N-methoxyphenyl maleimide, N-methylphenyl maleimide, N-carboxyphenyl maleimide, N-hydroxyphenyl maleimide, N-chlorophenyl maleimide, N-dimethylphenyl maleimide Nitro groups such as N-dichlorophenyl maleimide, N-bromophenyl maleimide, N-dibromophenyl maleimide, N-trichlorophenyl maleimide, N-tribromophenyl maleimide, alkoxy groups, alkyl groups N-substituted maleimide production method, characterized in that at least one member selected from the group consisting of a carboxyl group, a hydroxyl group, a halogen atom is substituted with a phenyl group N-substituted phenyl maleimide.

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