CN110283149A - Biomass diamines, its salt and its preparation based on furylamine and levulic acid - Google Patents

Abstract

The invention belongs to the field of organic polymer materials, and discloses biomass diamine, its salt, and its preparation based on furylmethylamine and levulinic acid, wherein the preparation method uses furylmethylamine and levulinic acid as raw materials, and acid as a catalyst , the target furan diamine salt product based on the structural formula furan diamine shown in the following formula is prepared by condensation reaction. The present invention adopts furylamine and levulinic acid as raw materials, and controls the overall flow process of the preparation method, the addition sequence of key reaction reagents, etc., and uses renewable resources as raw materials to prepare diamine salts, and the process is simple, the first time The furan diamine product with a specific chemical structure is prepared, and the defects such as limited source of raw materials or cumbersome steps of the preparation method are avoided. The obtained target furan diamine salt product is not only a kind of fine chemical with wide application, but also a kind of biomass Monomers for polymers, such as monomers for biomass hyperbranched polyamides.

Description

Biomass diamine, its salt, and its preparation based on furylmethylamine and levulinic acid

technical field

The invention belongs to the field of organic polymer materials, more specifically, relates to a kind of biomass diamine, its salt, and its preparation based on furyl methylamine and levulinic acid, and especially provides a kind of renewable resource furyl methylamine and A novel biomass platform compound 4,4-bis(5-aminomethylfuranyl)pentanoic acid (4,4-bis[5-(aminomethyl)furan-2-yl]pentanoic acid) with levulinic acid as the main raw material Preparation.

Background technique

Organic amine compounds are a class of basic chemical raw materials, widely used as catalysts, curing agents and other fine chemicals. In particular, diamines and polyamines are indispensable raw materials for high-performance polymers such as polyurethanes, polyamides, and polyimides. However, the existing diamines, such as p-phenylenediamine, naphthalene diamine, diphenyl ether diamine, hexamethylene diamine, etc., mostly use petroleum as raw material. The use of renewable resources instead of fossil resources to prepare fine chemicals and organic polymer materials is a necessary requirement for sustainable development. Because bio-based polymers can effectively reduce environmental pollution and carbon emissions, thereby reducing human dependence on petroleum resources.

Bio-based diamines refer to diamines prepared from renewable resources, mainly including long-chain diamines such as pentamethylenediamine, butylenediamine (putrescine), propylenediamine, and decanediamine. Its main synthesis methods are divided into fermentation method and oxidation-hydrogenation method using natural product castor oil as raw material. The main limitation of diamine preparation by fermentation is the long reaction time and limited source of raw materials; the preparation of decanediamine by castor oil is cumbersome.

Although furylamine (furfurylamine) is not a natural organic amine, it can be obtained by ammonification of furfural and has been prepared in industrialized batches. It is also considered to be a type of organic amine based on renewable resources. The use of furylamine to prepare diamines has important utilization significance and broad market prospects. In the existing scientific research, furan-basedbiamine has aroused widespread interest in the academic and industrial circles. The structural formula is shown in the following formula. These diamine compounds are all synthesized from furfurylamine. The basic method is furanmethylamine Catalyzed condensation with compounds containing aldehyde and ketone structures to obtain furan diamine. However, the currently publicly reported aldehyde and ketone compounds are mainly formaldehyde, acetaldehyde, acetone, butanone, benzaldehyde, acetophenone, etc., which come from petroleum, and there is no mention of bio-based aldehyde and ketone compounds.

Levulinic acid (levulinic acid) is a biomass platform compound that can be easily prepared from cellulose by an acid-catalyzed process and is considered to be one of the most important compounds in biomass transformation. The conversion of levulinic acid enriches the types of chemical species in renewable biomass, which can be considered an expanded field of biomass conversion. However, no biomass diamines based on furylamine and levulinic acid have been prepared so far.

Contents of the invention

In view of the lack of full biomass furan diamine in the prior art, and the inability to fully reflect the superiority of the bio-based organic amine furan methylamine, the purpose of the present invention is to provide biomass diamine, its salt, and its based on furan methylamine and The preparation of levulinic acid, wherein furylamine and levulinic acid are used as raw materials, and the overall process of the preparation method, the order of addition of key reaction reagents, etc. are controlled, and renewable resources are used as raw materials to prepare diamine salts, Moreover, the process is simple, and a novel furan diamine product with a specific chemical structure is prepared for the first time, and defects such as limited source of raw materials or cumbersome steps in the preparation method are avoided; The fine chemicals of biomass polymers are also monomers of biomass polymers, which can be used as monomers of biomass hyperbranched polyamides, functional polyureas, polyurethanes, polyetheramines, etc. It can be seen that based on the present invention, the use of renewable raw materials levulinic acid And furfurylamine can synthesize new monomers.

In order to achieve the above object, according to one aspect of the present invention, a novel biomass diamine or biomass diamine salt is provided, characterized in that, the biomass diamine is specifically furan diamine of the structural formula shown in the following formula:

The biomass diamine salt is specifically the salt of the structural formula furan diamine shown in the following formula:

According to another aspect of the present invention, a kind of preparation method based on the novel biomass diamine of furylamine and levulinic acid is provided, it is characterized in that, this method is to be raw material with furylmethylamine and levulinic acid, and acid is Catalyst, prepare the target furan diamine salt product based on the structural formula furan diamine shown in the following formula by condensation reaction:

The method specifically includes the following steps:

(1) Add furylmethylamine to the acid under the condition of -10℃～10℃; after all furylamine is added, add levulinic acid into the reaction system and react at 20℃～80℃ After 2h to 48h, the precipitate of furan diamine salt can be obtained; by collecting the precipitate, the crude product of furan diamine salt can be obtained; wherein, the molar ratio of the furan methylamine to the levulinic acid is 2 to 2.1: 1;

(2) Dissolving the crude product in water, adding alkali, removing inorganic salts and residual organic impurities, and finally acidifying, thereby purifying the crude product to obtain the refined product of the target furan diamine salt.

As a further preference of the present invention, in the step (1), the adding of methylfurylamine to the acid is specifically adding methylfurylamine to the acid dropwise, and the rate of addition is controlled so that the temperature fluctuation of the reaction system does not exceed 15°C.

As a further preference of the present invention, in the step (1), levulinic acid is added to the reaction system, specifically, levulinic acid is added dropwise to the reaction system, and the rate of addition is controlled so that the temperature fluctuation of the reaction system does not exceed 20 ℃.

As a further preference of the present invention, in the step (1), the acid is an inorganic acid, an organic acid or an acidic ionic liquid; wherein, the inorganic acid is hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid; the organic acid is formic acid Sulfonic acid, formic acid, acetic acid or their derivatives; correspondingly, the crude product of furan diamine salt is furan diamine mineral acid salt, furan diamine organic acid salt crude product.

As a further preference of the present invention, the step (2) is specifically:

Dissolve the crude product in water, add alkali, stir evenly to make the pH value alkaline, then extract with an organic solvent to remove residual organic impurities; then, rotary steam to remove excess water, crystallize the inorganic salt, and then The inorganic salt is removed by filtration, and the filtrate is acidified to precipitate a precipitate, and the precipitate is filtered and dried to obtain the refined product of the target furan diamine salt;

or:

Dissolving the crude product in water, adding alkali to precipitate all the inorganic salts, filtering to remove the precipitated inorganic salts, adjusting the pH value of the filtrate to make the solution alkaline, and then extracting with an organic solvent to remove residual organic impurities, Then, it is acidified to precipitate out, and the precipitate is filtered and dried to obtain the refined product of the target furan diamine salt.

As a further preference of the present invention, in the step (2), the acid used for the acidification is an inorganic acid or an organic acid, and the target furan diamine salt is a furan diamine inorganic acid salt or a furan diamine organic acid salt.

As a further preference of the present invention, in the step (2), the acid used for the acidification is hydrochloric acid, and the target furan diamine salt is furan diamine hydrochloride.

As a further preference of the present invention, in the step (2), the organic solvent is dichloromethane or chloroform, and the extraction is specifically multiple repeated extractions.

As a further preference of the present invention, in the step (1), before the condensation reaction starts, the mass percent concentration of the acid in the reaction system is >10%, preferably >20%.

Through the above technical scheme conceived by the present invention, compared with the prior art, furan methylamine and levulinic acid are used as raw materials, both of furyl methylamine and levulinic acid belong to renewable resource materials, and the whole biomass furan diamine is realized. and the preparation of derivatives thereof. The present invention uses furanylamine and levulinic acid as raw materials and the acid as a catalyst to prepare the target furanic diamine salt product through condensation reaction. The process is simple and overcomes the long reaction time of the prior art preparation process, limited sources of raw materials, or steps The process is cumbersome and other defects.

The target furan diamine salt obtained in the present invention can be an inorganic acid salt or an organic acid salt, and after deacidification and neutralization, a free amino product can be obtained; in addition, the carboxyl and amino groups in the structure can undergo derivatization reactions to obtain esterification, Amidation, secondary amine, tertiary amine and other derivative products. Taking furan diamine hydrochloride (that is, ((4-carboxybutane-2,2-diyl)bis(furan-5,2-diyl))dimethanaminium chloride as an example, its structural formula is as follows:

It has the following characteristics: 1. The structure contains a carboxyl group and two amino groups at the same time. It is a new type of bio-based AB ₂ type monomer, which can directly prepare hyperbranched or dendritic polyamides; 2. The product undergoes deacidification And, free amino products can be obtained; 3. The carboxyl and amino groups in the structure can undergo derivatization reactions to obtain esterification, amidation, secondary amines, tertiary amines and other derivative products.

In the present invention, by taking hydrochloric acid as an example in the process of preparing crude products, the concentration of hydrochloric acid is controlled to be >10%, preferably >20%, so as to obtain a higher yield; and in the acidification step of preparing refined products, the acid The concentration is controlled to >5%, and the product can be completely precipitated out. On the other hand, in the stage of reaction preparation to generate crude product, the present invention can directly use water (or directly use acid solution) as solvent instead of organic solvent, which further simplifies the preparation process. In addition, the present invention preferably adopts a product separation process with specific parameters and conditions, that is, using the difference in solubility of raw materials and products for separation, so as to achieve the purpose of raw material recovery and reuse.

Description of drawings

Fig. 1 is the hydrogen spectrum ( ¹ HNMR) of furan diamine hydrochloride prepared in the present invention.

Figure 2 is the carbon spectrum ( ¹ CNMR) of furan diamine hydrochloride prepared in the present invention.

Fig. 3 is the mass spectrum of furan diamine hydrochloride prepared in the present invention.

Fig. 4 is the hydrogen spectrum of the furandiamine methyl ester prepared by the present invention.

Fig. 5 is the hydrogen spectrum of the furan diamino ethyl ester prepared by the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

In general, the preparation method of the novel biomass diamine based on furylamine and levulinic acid among the present invention is to take furfurylamine and levulinic acid as starting raw materials, acid as catalyst, and obtain the prepared product through condensation reaction; specifically In other words, the following steps are involved:

1. Add furylamine to the acid at -10°C to 10°C to control the rate of addition to avoid a sharp rise in temperature; after the addition of furylamine is completed, add levulinic acid to the reaction system to control the rate of addition Control the reaction rate so that the reaction proceeds slowly. Then the temperature is raised to the set temperature, and the reaction is continued for a predetermined time. A large amount of white precipitate is formed in the system. Stop the reaction and cool to room temperature. The precipitate was collected by filtration, which was the crude product. In the reaction, the acid is used as a catalyst. Take hydrochloric acid as an example, the concentration is 10-40%, the molar ratio of furfurylamine and levulinic acid is 2-2.1:1, the reaction temperature is 20°C-80°C, and the reaction time is 2h-48h.

2. Product purification: Dissolve the crude product in water, add alkali, stir evenly, extract three times with organic solvent, then rotary steam to remove excess water, there is salt precipitation, filter to remove salt, acidify the filtrate, precipitate and precipitate, after filtration Dry to obtain the target product.

The preparation of the diamine salt monomer of the present invention will be further described through specific examples below.

Embodiment one

This embodiment comprises the following steps:

(1) Add 37%-40% hydrochloric acid solution in a three-necked flask equipped with an oil seal and a thermometer, slowly add furfurylamine therein at -10°C, control the rate of furfurylamine addition, and keep the temperature of the reaction mixture substantially constant. After the dropwise addition, the stirring reaction was continued for 30 min. Then add levulinic acid (the molar ratio of furfurylamine and levulinic acid is 2:1) to the system, control the dropping speed to make the reaction go on smoothly, after the dropping, raise the temperature to 50°C for 24 hours, during the reaction process, a large amount of white Precipitation occurs. After the reaction, the reaction mixture was cooled to room temperature, and the precipitate was collected by filtration, and the crude product was obtained after vacuum drying.

(2) Crude product refinement: Take the crude product and dissolve it in an appropriate amount of water, add alkali such as sodium hydroxide, etc. to adjust the pH value of the system to be alkaline, and use an organic solvent such as dichloromethane to extract three times to remove impurities. The water layer was collected, and then part of the water was removed by rotary evaporation, and sodium chloride crystals were precipitated, and the sodium chloride was removed by filtration. This process can be repeated many times to remove the inorganic salts produced by neutralization as much as possible. The pH value of the remaining solution was adjusted with concentrated hydrochloric acid (that is, concentrated hydrochloric acid with a concentration of 37%-40%) to make the system strongly acidic, and a large amount of white precipitates were precipitated. The precipitate was collected by filtration, which was the target product furan diamine hydrochloride. The chemical structure of the product was confirmed by NMR and high-resolution mass spectrometry.

Embodiment two

This embodiment comprises the following steps:

(1) Add 10% sulfuric acid solution in a three-necked flask equipped with an oil seal and a thermometer, slowly add furfurylamine dropwise therein at 0°C, react for 30min under stirring conditions, add levulinic acid (furfurylamine and The molar ratio of levulinic acid is 2.1:1), and then heated up to 80°C for 2 hours to produce a precipitate. Since the precipitate is too fine, add an appropriate amount of ethanol and then centrifuge, then add ethanol several times to wash and centrifuge, then put it in a vacuum drying oven to dry Then get the crude product.

(2) Crude product purification: take the crude product and dissolve it in an appropriate amount of distilled water, add barium hydroxide under stirring, form a large amount of white barium sulfate white precipitate, filter to remove the barium sulfate precipitate, continue to add barium hydroxide in the filtrate until there is no barium sulfate until precipitation occurs. The precipitate was removed by filtration, and the filtrate was adjusted to pH ≥ 10 with barium hydroxide, and extracted three times with dichloromethane to remove residual organic impurities. Then the filtrate was acidified with 20% sulfuric acid, a large amount of white precipitate was precipitated, and the precipitate was collected by filtration, which was the target product.

Embodiment three

This embodiment comprises the following steps:

(1) Add 35% nitric acid solution in a three-necked flask equipped with an oil seal and a thermometer, slowly add furfurylamine dropwise at 10°C, react for 30min under stirring, add levulinic acid (furfurylamine and The molar ratio of levulinic acid is 2.05:1), then allow the reaction to stir at 20°C (due to the oxidation of nitric acid, the reaction temperature should not exceed 30°C) for 24 hours, and a precipitate occurs. Since the precipitate is too fine, add an appropriate amount of ethanol and centrifuge. After adding ethanol several times to wash, centrifuge, and dry in a vacuum oven to obtain a crude product.

(2) Purification of the crude product: take the crude product and dissolve it in water, add sodium hydroxide, and adjust the pH to be alkaline. Extract three times with chloroform to remove possible organic impurities. The water phase was distilled under reduced pressure, and then the excess water was removed by rotary evaporation. Sodium nitrate was precipitated, and the sodium nitrate was removed by filtration. The obtained solution was acidified with 25% nitric acid, and the precipitate was precipitated. After centrifugation, it was dried to obtain the product.

Embodiment four

This embodiment comprises the following steps:

(1) Add 25% phosphoric acid solution into a three-necked flask equipped with an oil seal and a thermometer, slowly add furfurylamine dropwise to it at -2°C, control the rate of addition so that the temperature of the mixture remains basically stable, and stir the reaction for 30 minutes after the addition is completed . Then add levulinic acid (the molar ratio of furfurylamine and levulinic acid is 2.02:1) to the system, and then raise the temperature to 50°C for 48 hours to generate massive precipitates. The precipitate was collected by filtration and dried in a vacuum oven to obtain a crude product.

(2) Purification of the crude product: take the crude product and dissolve it in distilled water, slowly add calcium hydroxide, and the system immediately produces a large amount of calcium phosphate precipitates. Filter to remove the precipitate, and continue to add calcium hydroxide to the filtrate until no new precipitate is formed and the system is alkaline. The precipitate was removed by filtration, and the filtrate was extracted three times with dichloromethane to remove organic impurities. Then the filtrate was acidified with 37% hydrochloric acid, and a large amount of white precipitate was precipitated, which was collected by filtration and vacuum-dried to obtain the target product.

Embodiment five: scale-up experiment

Proceed as follows:

1. Add commercially available hydrochloric acid solution into a 25L glass reactor equipped with a cooling circulation pump, polytetrafluoroethylene stirring, and a thermometer. Turn on the low-temperature circulation pump to cool the hydrochloric acid solution in the kettle to -10°C. Slowly add furfurylamine dropwise under stirring, and control the temperature in the kettle not to exceed 10°C. After the addition of furfurylamine is finished, the stirring reaction is continued and the temperature in the kettle is controlled between -5 and 0°C. Then add levulinic acid (the molar ratio of furfurylamine and levulinic acid is 2:1) to the system, control the rate of addition to allow the reaction to proceed smoothly, and the temperature does not exceed 15°C. After the dropwise addition, the temperature was raised to 50° C. for 24 hours, and a large amount of white precipitates were produced during the reaction. After the reaction, the reaction mixture was cooled to room temperature under stirring, and the precipitate was collected by filtration with a centrifugal filter, and the crude product was obtained after vacuum drying.

2. Crude product refining: Take the crude product and put it into a clean 25L glass reactor, add deionized water to dissolve the crude product. Add 5% sodium hydroxide solution under temperature control to adjust the pH value of the system to be alkaline. Add dichloromethane into the reaction kettle, stir for 15 minutes, let stand to separate layers, and then release the dichloromethane layer from the outlet. This process was repeated three times, and the dichloromethane layer was separated as cleanly as possible. Add 37% concentrated hydrochloric acid to the remaining aqueous phase to adjust the pH value, making the system acidic and a large amount of white precipitates. The precipitate was collected by centrifugation and washed with a small amount of hot isopropanol. Vacuum drying is the target product furan diamine hydrochloride.

Embodiment six:

Esterification reaction of furan diamine hydrochloride:

In a three-necked flask with a condenser, add 10 g of furan diamine hydrochloride, 400 mL of anhydrous methanol, and 0.23 g of p-toluenesulfonic acid monohydrate, stir magnetically under the protection of argon, and heat to reflux for 7 hours. After the reaction was completed, the crude product was obtained by rotary evaporation to obtain a white solid. The crude product was washed three times with isopropanol, and then dried in vacuum to obtain a refined esterified product. The reactions were performed in quantitative yields, and the chemical structures of the products were characterized by H-NMR spectroscopy.

Change the type of alcohol, that is, replace methanol with ethanol, isopropanol, ethylene glycol, etc., to obtain the corresponding esterification product. The esterification product is also a monomer of type AB ₂ hyperbranched polymer.

Above-mentioned embodiment is only example with hydrochloride, vitriol, nitrate refined product, in addition, in refining (or purifying) process, carry out by adopting other kinds of acids such as other organic acid or inorganic acid or acidic ionic liquid Acidification, can be corresponding to other types of salt. Taking acetic acid as an example, its derivatives include trichloroacetic acid and the like.

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (10)

1. a kind of novel biomass diamines or biomass diamine salts, which is characterized in that the biomass diamines is specially such as following formula institute Show structural formula furans diamines:

The biomass diamine salts are specially the salt of structural formula furans diamines of being shown below:

2. a kind of preparation method of the novel biomass diamines based on furylamine and levulic acid, which is characterized in that this method It is using furylamine and levulic acid as raw material, acid is catalyst, is prepared by condensation reaction based on the knot that is shown below The desired furan diamine salts product of structure formula furans diamines:

This method specifically includes the following steps:

(1) under conditions of -10 DEG C~10 DEG C, furylamine is added into acid；After furylamine is all added, then by acetyl Propionic acid is added in reaction system, and 2h~48h is reacted at 20 DEG C~80 DEG C, and the precipitating of furans diamine salts can be obtained；It receives Collect the precipitating, the crude product of furans diamine salts can be obtained；Wherein, the molar ratio of the furylamine and the levulic acid is 2~2.1:1；

(2) crude product is soluble in water, alkali is added, removes inorganic salts and remaining organic impurities, is finally acidified, thus right The crude product is purified to obtain the smart product of desired furan diamine salts.

3. the preparation method of the novel biomass diamines as claimed in claim 2 based on furylamine and levulic acid, feature It is, in the step (1), the furylamine that is added into acid is specifically that furylamine is added dropwise into acid, and speed is added dropwise in control Degree makes the temperature fluctuation of reaction system be no more than 15 DEG C.

4. the preparation method of the novel biomass diamines as claimed in claim 2 based on furylamine and levulic acid, feature It is, in the step (1), levulic acid is added in reaction system, levulic acid is specifically added drop-wise to reaction system In, control rate of addition makes the temperature fluctuation of reaction system be no more than 20 DEG C.

5. the preparation method of the novel biomass diamines as claimed in claim 2 based on furylamine and levulic acid, feature It is, in the step (1), the acid is inorganic acid, organic acid or acidic ion liquid；Wherein, the inorganic acid be hydrochloric acid, Sulfuric acid, nitric acid or phosphoric acid；The organic acid is methanesulfonic acid, formic acid, acetic acid or their derivative；Correspondingly, the furans two The crude product of amine salt is furans diamines inorganic acid salt, furans diamines acylate crude product.

6. the preparation of the novel biomass diamines based on furylamine and levulic acid as described in claim 2-5 any one Method, which is characterized in that the step (2) is specifically:

The crude product is soluble in water, alkali is added, stirring evenly keeps pH value alkaline, is then extracted with organic solvent to remove Remaining organic impurities；Then, revolving removes extra moisture, and inorganic salts crystallization is precipitated, then after filtering out inorganic salts, And make to be precipitated by acidification of filtrate and precipitate, it will be dry after precipitating filtering, the smart product of desired furan diamine salts can be obtained；

Either:

The crude product is soluble in water, alkali is added, after precipitating inorganic salts whole Precipitation, filtering removal inorganic salts, adjusts The pH value for saving filtrate keeps solution alkaline, is then extracted with organic solvent to remove remaining organic impurities, then acidification makes to analyse It precipitates out, will be dry after precipitating filtering, the smart product of desired furan diamine salts can be obtained.

7. the preparation of the novel biomass diamines based on furylamine and levulic acid as described in claim 2-6 any one Method, which is characterized in that in the step (2), the acid used that is acidified is inorganic acid or organic acid, the desired furan two Amine salt is furans diamines inorganic acid salt or furans diamines acylate.

8. the preparation method of the novel biomass diamines as claimed in claim 7 based on furylamine and levulic acid, feature It is, in the step (2), the acid used that is acidified is hydrochloric acid, and the desired furan diamine salts are furans diamine hydrochloride.

9. the preparation method of the novel biomass diamines as claimed in claim 2 based on furylamine and levulic acid, feature It is, in the step (2), the organic solvent is dichloromethane or chloroform, and the extraction is specifically that extraction is repeated several times It takes.

10. the preparation method of the novel biomass diamines as claimed in claim 2 based on furylamine and levulic acid, feature It is, in the step (1), before the condensation reaction starts, mass percentage concentration > 10% of the acid in the reaction system, It is preferred that > 20%.