WO2022127640A1

WO2022127640A1 - Process for synthesis of furan-based diamines

Info

Publication number: WO2022127640A1
Application number: PCT/CN2021/135822
Authority: WO
Inventors: Ruijing Guo; Raul Pires; Saskia BEUCK; Irene Cristina Latorre Martinez; Xiangcheng Pan; Yuan Jiang
Original assignee: Covestro Deutschland Ag
Priority date: 2020-12-16
Filing date: 2021-12-06
Publication date: 2022-06-23

Abstract

The invention provides a process for the synthesis of furan-based diamines based on renewable resources.

Description

Process for synthesis of furan-based diamines

The invention relates to a process for the synthesis of furan-based diamines by renewable resources. There are growing interests on bio-based chemicals in the industry following increasing awareness and demands of renewable materials to maintain a sustainable economic growth.

As an important industrial raw material, furan-based diamines are getting more and more attention. Furan-based diamines are the potential monomer materials can be derived from renewable bio-based chemicals.

As to the synthesis of a bisfuran diamine, there is a known method in which furfurylamine is reacted with a ketone.

CN106,674,214A describes the specific process. After the conversion of furfurylamine, the reaction mixture is quenched with NaOH aqueous solution. Bisfuran diamine is directly obtained using ethyl acetate or dichloromethane extraction.

Isocyanate-Free Synthesis and Characterization of Renewable Poly (hydroxy) urethanes from Syringaresinol by Marine Janvier, Paul-Henri Ducrot and Florent Allais, (ACS Sustainable Chem. Eng. 2017, 5, 8648-8656) disclosed a method of replacement of petro-sourced and toxic bisphenol A (BPA) , syringaresinol, a naturally occurring bisphenol deriving from sinapic acid, has been proposed as a greener and safer alternative.

US 9,840,485 BI published a bisfuran dihalide having a structure represented by the following formula (1) :

wherein R1 is a divalent hydrocarbon group represented by-CR2R3- (wherein each of R2 and R3 independently represents a hydrogen atom or a monovalent hydrocarbon group, and R2 and R3 may together form a cyclic structure) , or a carbonyl group (-C (=0) -) ; and each X independently represents a halogen atom.

It is tried and known for processes in providing furan-based diamines such as above-mentioned approaches. However, those approaches are either at very small amount of production, or resulting in low yield, holding the development or commercialization of the synthesis of furan-based diamines via bio-based raw materials.

There is therefore a need for a process for preparing furan-based diamines with larger scale, better conversion rate and higher yields.

One aspect of the present invention is concerned specifically on an effective approach in the synthesis of furan-based diamines.

Taking account of above need, the present invention provides a method for producing bisfuran diamine, comprising:

reacting of furfurylamine with at least an aqueous acid solution to get a reaction mixture (a) ;

adding at least an aldehyde or ketone into the reaction mixture (a) at≥30℃, preferably≥35℃, more preferably 37-59℃, even more preferably 37-53℃, especially more preferably 37-52℃, for ≥20 hours, preferably≥30 hours, more preferably≥50 hours, even more preferably 50-95 hours to get a reaction mixture (b) ;

adding at least an aqueous alkali solution into the reaction mixture (b) to provide the bisfuran diamine;

wherein the equivalent ratio of the furfurylamine and the acid is 2.0: 5.0-2.0: 2.3, preferably 2.0: 4.5-2.0: 2.3. more preferably 2.0: 4.0-2.0: 2.3.

Preferably, the acid is selected from HCl, H2SO4 and H3PO4, preferably HCl.

Preferably, comparing the method comprising equivalent ratio of the furfurylamine and the acid out of 2.0: 5.0-2.0: 2.3, the molar yield of the method comprising the equivalent ratio of the furfurylamine and the acid is 2.0: 5.0-2.0: 2.3 increases≥5, preferably≥10..

Preferably, the aldehyde or ketone is selected from trifluoracetaldehyde, acetaldehyde, propionaldehyde, glyceraldehyde, thiazolecarboxaldehyde, oxazolecarboxaldehyde, imidazolecarboxaldehyde, cyclopropanecarboxaldehyde, butyraldehyde, isobutyraldehyde, furfural, furancarboxaldehyde, acetone, thiophenecarboxaldehyde, pyrrolecarboxaldehyde, 1, 1, 1-trifluoroacetone, 1, 3-dichloroacetone, chloroacetone, hydroxyacetone, octafluoro-2-butanone, cyclobutanone, 3-buten-2-one, acetoin, 4- hydroxy-2-butanone, cyclopropyl methyl ketone, 2-cyclohexen-1-one, cyclohexanone and any of their combination, more preferably acetone.

Preferably, the equivalent ratio of the furfurylamine and aldehyde or ketone is 2.0: 5-2.0: 0.8, preferably 2.0: 4.9-2.0: 0.9.

Preferably, the aqueous alkali solution is selected from NaOH, KOH, Na2CO3, K2CO3, LiOH and/or their combination.

Preferably, the content of the alkali is≥20wt%, preferably≥25wt%, more preferably≥28wt%, based on the total mass of the aqueous alkali solution.

Preferably, the method further comprises:

a mixture (c) is obtained following the neutralization and then the mixture (c) is extracted to provide the bisfuran diamine.

Preferably, the organic solvent is selected from ethanol, formic acid, butanol, isopropanol, dichloromethane, methanol, acetic acid and any of their combination.

Preferably, the aldehyde or ketone is selected from acetone.

Preferably, the bisfuran diamine is selected from 5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine.

Preferably, the molar yield of bisfuran diamine, preferably the 5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine is≥35%, preferably≥40%, more preferably≥50%.

Preferably, the purity of the bisfuran diamine, preferably the (5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine is≥98%, preferably≥99%.

Preferably, the conversion rate of the reaction to get the bisfuran diamine, preferably the (5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine is≥40%, preferably≥45%, more preferably≥50%.

Another aspect of the present invention is concerned specifically on bisfuran diamine prepared by the method as described above.

Preferably, the bisfuran diamine is selected from the (5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine.

Another aspect of the present invention is concerned specifically use of the bisfuran diamine of the invention in producing raw materials for polyurethane.

Embodiments of the invention are described in detail hereinafter. These may be combined with one another as desired, unless the context unambiguously suggests anything different to the person skilled in the art. Through various embodiments, surprisingly, we find that the methods of the present invention successfully achieved that, firstly, a much better conversion rate of the raw materials for production of the bisfuran diamine; secondly, it is a more efficient route that saved the raw materials from wasting and therefore more environment-friendly; thirdly, there are more effective means provided to produce furan-based diamines with a much higher purity and yield; and fourthly, the invention enables a large move in commercialization of raw materials of bio-based chemicals substituting petrochemical raw materials, and therefore may mean significant improvement in practice of circular economy and green energy economy.

In the method of the invention, the starting state that exists in each case is converted to the state of production under normal conditions in such a way that the problems mentioned at the outset occur to a slight extent at most, if at all, as set out in detail hereinafter.

In implementation of the method of the invention, certain amount of an aqueous solution of an acid, which can be selected from HCl, H2SO4 and H3PO4 solution, was introduced in a flask e.g. a two-necked round-bottomed flask and cooled down to about 0℃ with an ice bath or other cooling methods. Relevant amount of furfurylamine was then added to the flask at around 0-20℃, preferably 0-10℃to get a reaction mixture (a) .

An aldehyde or ketone, preferably acetone was added to the reaction mixture (a) and was stirred at≥30℃, preferably≥35℃, more preferably 37-59℃, even more preferably 37-53℃, especially more preferably 37-52℃, for≥20 hours, preferably≥30 hours, more preferably≥50 hours, even more preferably 50-95 hours to get a reaction mixture (b) . The aldehyde or ketone can be selected from trifluoracetaldehyde, acetaldehyde, propionaldehyde, glyceraldehyde, thiazolecarboxaldehyde, oxazolecarboxaldehyde, imidazolecarboxaldehyde, cyclopropanecarboxaldehyde, butyraldehyde, isobutyraldehyde, furfural, furancarboxaldehyde, acetone, thiophenecarboxaldehyde, pyrrolecarboxaldehyde, 1, 1, 1-trifluoroacetone, 1, 3-dichloroacetone, chloroacetone, hydroxyacetone, octafluoro-2-butanone, cyclobutanone, 3-buten-2-one, acetoin, 4-hydroxy-2-butanone, cyclopropyl methyl ketone, 2-cyclohexen-1-one, cyclohexanone and any of their combination.

After the completion of reaction, the reaction mixture (b) was cooled down to 15-30℃, preferably 20-25℃ slowly. Then the resulting precipitate was collected by filtration. The crude mixture was dissolved in certain amount of H2O. Preferably, the pH of the solution was adjusted to around 10 with adding appropriate amount of aqueous alkali solution to provide a mixture (c) . The aqueous alkali solution of the invention includes but not limited to NaOH, KOH, Na2CO3, K2CO3, LiOH and/or their combination, preferably, the aqueous alkali is selected from NaOH.

The mixture (c) was extracted with an organic solvent, which can be selected from ethanol, formic acid, butanol, isopropanol, dichloromethane, methanol, acetic acid and any of their combination, and preferably dichloromethane. The organic fractions were collected, dried on anhydrous MgSO4 and the organic solvent was removed under reduced pressure to provide the bis-furan diamine.

In a preferred embodiment of the invention, the bisfuran diamine is selected from the (5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine.

In a preferred embodiment of the invention, the molar yield of bisfuran diamine, preferably the 5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine is≥35%, preferably≥40%, more preferably≥50%.

In a preferred embodiment of the invention, the purity of the bisfuran diamine, preferably the (5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine is≥98%, preferably≥99%.

In a preferred embodiment of the invention, the conversion rate of the reaction to get the bisfuran diamine, preferably the (5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine is≥40%, preferably≥45%, more preferably≥50%.

The reaction of a preferred embodiment of the method of the invention can be interpreted by below formula.

A person skilled in the art is aware that some bio-based chemicals can be an alternative or even replace certain well-known used raw materials from petro streamlines in laboratory. However, in principle, scaling up is extremely difficult and the yields are usually not possible to enable commercialization.

What is essential to the invention is that through numerous experiments, we surprisingly find that, the combination of each features of the method of the present invention has fulfilled not only an efficient route of producing bio-based diamines, but much larger scale of production with high yields.

Specifically, the procedure of the invention gives rise to the following advantages for raw materials for the preparation of polyurethanes:

I. successfully achieved a much larger scale of production for bio-based and furan-based diamines;

II. significantly improved the yield of the final product of the furan-based diamines;

III. successfully discovered very efficient routes to produce the furan-based diamines;

IV. using more suitable chemicals and/or process such as alkali, filtration, temperature and reaction time etc., making the method more economic and hereof more attractive for industrial development;

V. enabling a big step towards commercialization of bio-based diamines in producing polyurethanes and therefore enhancing the sustainability and use of renewable feedstocks for green economy.

Thus, the method of the invention enables, by ensuring above mentioned advantages, a big step towards sustainable energy and economy.

Examples

Test Methods

Weight, using electronic balance (OHAUS and Techcomp) to weigh the weight of the chemicals;

Purity, according to analysis of HNMR spectra;

Molar yield of the product of the invention is calculated by molar yield=weight of substance actually generated/weight of substance theoretically generated*100%. The molar yield of the product from each step is calculated separately per aforementioned formula.

Weight of substance theoretically generated=weight of the starting substance/molecular weight of the starting substance*molecular weight of the product.

TLC, thin layer chromatography, a chromatographic method for separating mixtures or identifying the product on a glass plate covered with a thin layer of adsorbent on a plastic sheet or aluminium foil.

Raw Materials

Furfurylamine, 99%, 3A Chemicals;

Acetone, ≥99.5%, Greagent;

HCl solution, 36.0～38.0%, Sinopharm Chemical Reagent Co., Ltd;

MgSO ₄, ≥98%, Greagent; CH ₂Cl ₂, ≥99.5%, Greagent;

NaOH, ≥98%, Greagent;

Chromatography (TLC) , Rushan Taiyang Desiccant Co., Ltd;

The detailed information of the methods of the invention are presented as in the examples 1 and 5. Other examples are proceeded under similar steps with differences indicated in chart I.

Example 1

An 18 wt. %aqueous solution of HCl (103 mL) was introduced in a two-necked round-bottomed flask and cooled down to 0℃ with an ice bath. Furfurylamine (30 g, 0.31 mol) was then added dropwise to the reaction mixture at 0-10℃. Once this addition was completed, acetone (26.9 g, 0.46 mol) was added to the mixture. The reaction mixture was stirred at 40-50℃ for 67.5 hours. After the completion of reaction, the mixture was cooled down to 20-25℃ slowly. Then the resulting precipitate was collected by filtration. The crude mixture was dissolved in 75 mL H2O. The pH of the solution was adjusted to 10 with adding 30 wt. %aqueous NaOH solution. The mixture was extracted with dichloromethane (150 mL) . The organic fractions were collected, dried on anhydrous MgSO4 and dichloromethane was removed under reduced pressure to yield (5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine as brown oil (20.51 g, 56.7%yield) .

Example 5

An 18 wt. %aqueous solution of HCl (2746 mL) was introduced in a two-necked round-bottomed flask and cooled down to 0℃ with an ice bath. Furfurylamine (800 g, 8.24 mol) was then added dropwise to the reaction mixture at 0-10℃. Once this addition was completed, acetone (717.6 g, 12.36 mol) was added to the mixture. The reaction mixture was stirred at 40-50℃ for 84.5 hours. After the completion of reaction, the mixture was cooled down to 20-25℃ slowly. Then the resulting precipitate was collected by filtration. The crude mixture was dissolved in 3000 mL H2O and decolorized with activated carbon (40 g, 12 h at room temperature) . The resulting solution was then filtered over a G-3 filter funnel containing Celite. The pH of the brown filtrate was adjusted to 10 with adding 30 wt. %aqueous NaOH solution. The mixture was extracted with dichloromethane (4000 mL) . The organic fractions were collected, dried on anhydrous MgSO4 and dichloromethane was removed under reduced pressure to yield (5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine as brown oil (600 g, 62.2%yield) .

Chart I-Comparative Examples C1-C5 and Examples 2-5.

From Chart I, in general the yield will be increasing following the raise of the temperature, however, if the temperature reaches certain line, there will be more impurities than accepted. Therefore, we surprisingly find that, with the specific scope of the temperature and reaction term, the method of the invention presents a much more efficient route to produce furan-based diamines.

Especially, comparing the method comprising equivalent ratio of the furfurylamine and the acid out of 2: 5-2: 2.3, the molar yield of the method comprising the equivalent ratio of the furfurylamine and the acid is 2: 5-2: 2.3 increases significantly.

Chart II shows the example 6, showing the impact of temperature and reaction time on conversion rate.

Chart II-Impact on Conversion Rate

From the data as shown in Chart I and II, an appropriate temperature, reaction time and suitable other factors can result in better yield and conversion rate. Moreover, the equivalent of the raw materials can affect the yield as well.

As the examples show, surprisingly, when we use the method of the present invention, not only the final product is obtained, but a much larger scale of production of the furan-based diamines is successfully fulfilled as well. Moreover, the quality, purity and yield are all significantly improved.

Claims

A method for producing bisfuran diamine, comprising:

i. reacting of furfurylamine with at least an aqueous acid solution to get a reaction mixture (a) ;

ii. adding at least an aldehyde or ketone into the reaction mixture (a) at ≥30℃, preferably ≥35℃, more preferably 37-59℃, even more preferably 37-53℃ for ≥20 hours, preferably ≥30 hours, more preferably≥50 hours, even more preferably 50-95 hours to get a reaction mixture (b) ;

iii. adding at least an aqueous alkali solution into the reaction mixture (b) to provide the bisfuran diamine;

wherein the equivalent ratio of the furfurylamine and the acid is 2.0: 5.0-2.0: 2.3, preferably 2.0: 4.5-2.0: 2.3.
The method according to claim 1, wherein the aqueous acid solution is selected from HCl, H2SO4 and H3PO4 solution, preferably HCl.
The method according to claim 1 or 2, comparing the method comprising equivalent ratio of the furfurylamine and the acid out of 2.0: 5.0-2.0: 2.3, the molar yield of the method comprising the equivalent ratio of the furfurylamine and the acid is 2.0: 5.0-2.0: 2.3 increases ≥5, preferably ≥10.
The method according to claim 1, wherein the aldehyde or ketone is selected from trifluoracetaldehyde, acetaldehyde, propionaldehyde, glyceraldehyde, thiazolecarboxaldehyde, oxazolecarboxaldehyde, imidazolecarboxaldehyde, cyclopropanecarboxaldehyde, butyraldehyde, isobutyraldehyde, furfural, furancarboxaldehyde, acetone, thiophenecarboxaldehyde, pyrrolecarboxaldehyde, 1, 1, 1-trifluoroacetone, 1, 3-dichloroacetone, chloroacetone, hydroxyacetone, octafluoro-2-butanone, cyclobutanone, 3-Buten-2-one, acetoin, 4-hydroxy-2-butanone, cyclopropyl methyl ketone, 2-Cyclohexen-1-one, cyclohexanone and any of their combination, preferably acetone.
The method according to claim 1 or 2, wherein the equivalent ratio of the furfurylamine and aldehyde or ketone is 2.0: 5-2.0: 0.8, preferably 2.0: 4.9-2.0: 0.9.
The method according to claim 1 or 2, wherein the alkali is selected from NaOH, KOH, Na2CO3, K2CO3, LiOH and/or their combination, preferably NaOH.
The method according to claim 1 or 2, wherein the content of the alkali is ≥20wt%, preferably ≥25wt%, more preferably ≥28wt%, based on the total mass of the aqueous alkali solution.
The method according to claim 1 or 2, wherein the method further comprises:

iv. a mixture (c) is obtained following the neutralization and then the mixture (c) is extracted to provide the bisfuran diamine.
The method according to claim 8, wherein the organic solvent is selected from ethanol, formic acid, butanol, isopropanol, dichloromethane, methanol, acetic acid and any of their combination.
The method according to claim 1 or 2, wherein the bisfuran diamine is selected from 5, 5'- (propane-2, 2-diyl) bis (furan-5, 2-diyl) ) dimethanamine.
The method according to claim 10, wherein the molar yield of the bisfuran diamine is ≥35%, preferably ≥40%, more preferably ≥50%.
The method according to claim 10 or 11, wherein the purity of the bisfuran diamine is ≥98%, preferably ≥99%.
The method according to claim 10 or 11, wherein the conversion rate of the reaction to get the bisfuran diamine is ≥40%, preferably ≥45%, more preferably ≥50%.
Bisfuran diamine prepared by the method according to any of the claims 1-13.
Use of the bisfuran diamine according to claim 14 in producing raw materials for polyurethane.