KR20160106571A - A process for synthesis of furan derivative using an acid catalyst and preparation thereof - Google Patents

Abstract

According to an aspect of the present invention, there is provided a method for producing a sugar alcohol, comprising: contacting a sugar with a single-phase organic solvent to obtain a reaction mixture; And treating the reaction mixture in the presence of an acid catalyst to a temperature in the range of from 100 DEG C to 180 DEG C for a period of time ranging from 0.5 minutes to 4.0 hours to obtain at least 70% conversion of the sugar to the single furan derivative, A homogeneous acid catalyst, a heterogeneous acid catalyst, and combinations thereof. In addition, a process for producing a heterogeneous solid acid catalyst is provided.

Description

TECHNICAL FIELD The present invention relates to a method for synthesizing a furan derivative using an acid catalyst,

The object of the present invention is generally a process for the synthesis of furan derivatives using acid catalysts in monophasic organic solvents. The subject of the present invention further relates to an acid catalyst and its preparation.

Furan derivatives such as 5-methylfurfural and 5-methylfurfural alcohol, as well as hydroxymethylfurfural and furfural are products of the saccharide dehydration reaction with high industrial value. 5-hydroxymethyl furfural (5-HMF) is a multipurpose and multifunctional organosilane with a wide range of applications in various fields of synthetic organic chemistry, such as bulk chemicals, fine chemicals, pharmaceuticals, pesticides, It is a molecule. The structure of 5-HMF is shown below.

5-hydroxymethyl furfural

Due to the potential of 5-HMF for the production of furan 2,5-dicarboxylic acids (FDCA) required for the production of industrially important bio-based chemicals such as bio-based polymers, chemicals and pharmaceuticals , The synthesis of 5-HMF is of great interest in the chemical industry. Furan 2,5-dicarboxylic acid derived polymers are potential alternatives to petroleum-based terephthalic acid polymers. That is, large-scale replacement of petroleum-based polymers by bio-based polymers provides a significant basis for green chemistry in the polymer industry. However, the main role for this substitution is the synthesis of 5-HMF and thus 5-HMF synthesis occupies a small position for the synthesis of the bio-based product.

The synthetic chemistry of 5-HMF begins with the hexose saccharides glucose and fructose, more specifically acid-catalyzed cyclodextration from fructose. Since synthetic chemical applications for the preparation of 5-HMF are directed towards the development of acid catalysis, a number of acid catalysts have been used for this purpose, such as mineral acids, inorganic acids and solid acids. However, synthetic methods for producing 5-HMF by acid catalysis suffer from a number of technical problems in terms of yield, selectivity, process feasibility, and process economics. Due to the complex chemistry between the reaction substrate, the catalyst used for the dehydration reaction and the separation of reaction products, a number of problems arise during the synthesis of 5-HMF.

Another important factor affecting 5-HMF synthesis is the type of catalyst used for the dehydration reaction. Various types of organic, inorganic and mineral acids have been used as in-situ catalysts for 5-HMF synthesis. However, most of these processes suffer from the corrosive nature of mineral acids as well as handling difficulties due to difficult catalytic separation protocols from the reaction mixture and subsequent catalyst recycling.

Thus, heterogeneous acid catalysis as well as various solid acid catalysts such as zeolite, silica and Amberlyst resin have been explored and possible alternatives as possible alternatives. Ken-ichi Shimizu and co-workers reported the use of heterogeneous polyacids, zeolites and acid resins ( Catalysis Communications , 2009, 10 , 1849-1853) and DMSO as a solvent. Although higher yields were obtained as a result of the use of heterogeneous catalysis, the high boiling point of the solvent made it difficult to separate the product.

Use Eugene Zhang (Yugen zhang) report (ChemSusChem, 2011, 12, 1745-1748 ) is aqueous HCl as a catalyst was added to initiate the synthesis of 5-HMF in the isopropyl alcohol. However, the use of halogenated, corrosive HCl as a catalyst in aqueous conditions has resulted in problems of product separation as well as catalyst recovery problems, with difficulties in handling during large scale manufacturing.

US2007757461 discloses a process for the preparation of mineral acids, zeolites, silica-, silica-alumina, and acid groups, cation exchange resins, and mixtures thereof, in a biphasic reactor with aqueous and organic phases of 1-butanol, DCM, MIBK, 2- , A Lewis acid, a heteropoly acid. However, this invention also uses modifiers such as DMSO, DMF, N-methylpyrrolidinone (NMP) that are difficult to separate and environmentally friendly.

Similarly, Patent document WO2009 / 076627, US2009 / 0156841, US7579489, EP2233476 and [Lve et.al (ChemSusChem, 2012, 5, 1737-1742)] is DMF, N- methylpyrrolidinone high boiling point solvent such as (NMP) Discloses the use of a heterogeneous catalyst, Amberlyst-35 resin, having a total yield of less than 80%. The solvents used are non-eco-friendly and require high energy to separate them from the reactants.

Typically, aqueous-based solvents and ionic liquids are used for the synthesis of 5-HMF in the presence of acid catalysts. However, due to the higher solubility of 5-HMF in water, the procedure becomes complicated and requires a large amount of organic solvent for extraction. This substantially increases the process cost and unit work for bulk manufacturing of 5-HMF. This requires optimization of solvents and catalyst systems that are not only cost effective, but also provide ease of processing operations.

WO2011124639 is an enumeration of the claims relating to each mineral and Lewis acid catalyst, such as the use of aqueous HCl, AlCl ₃ by using a salt, such as NaCl, LiCl, LiBr, LiNO _3, KCl, KBr, KNO _3, FeCl ₃ in a biphasic organic solvent , Wherein the ideal organic solvent consisted of a mixture of water and methyl isobutyl ketone (MIBK). However, low yields (52%) and selectivities (less than 65%) were obtained as a result of the disclosed method of the present invention. The method also uses halogenated catalysts and salts that cause environmental problems as well as corrosion problems.

Microwave assisted reactions for the synthesis of 5-HMF have significance because they reduce reaction time, increase selectivity and reduce energy consumption. Thomas S. Hansen and co-workers ( Carbohydrate Research, 2009, 344 , 2568-2572) reported that microwave assisted 5-HMF at only 52% HMF yield by using an aqueous HCl catalyst at 200 & Synthesis. Xinhua Qi and co-researchers ( Ind . Eng . Chem . Res. 2008, 47, 9234-9239) reported HMF synthesis by using a mixed organic solvent system comprising a strongly acidic cation-exchange resin catalyst under microwave heating conditions and a 70:30 w / w ratio of acetone and DMSO. As a result of the reaction, 80% yield was obtained at a reaction time of 10-30 minutes.

Sudipta De and co-workers ( Green Chem . , 2011, 13 , 2859) found that the use of Lewis acid catalyst AlCl ₃ in the solvent DMSO and the ideal system, water-MIBK yields 21.4-60.6% We report microwave assisted synthesis of -HMF. (Green Chem., 2008, 10, 799-805) showed the yield of 5-HMF and 94% conversion at 150 ° C as high as 73.4% in an acetone-water mixture in the presence of a cation exchange resin catalyst Microwave assisted heating for HMF synthesis was used. Sakita Dutta and co-workers ( Applied Catalysis A, vol. 409-410 , 133-139 ) synthesized microwave assisted 5-HMF synthesis by using mesoporous TiO ₂ nanoparticles in solvent DMSO and NMP Respectively.

WO2012 / 015616 A1 obtains a microwave assisted synthesis of 5-HMF at 0-69.47% yield by using a catalytic amberlist and H ₂ SO ₄ at a reaction time of 5-30 minutes using a DMSO solvent. This microwave assisted synthesis method of 5-HMF also leads to a further problem of lower yield, selectivity, the use of non-environmentally friendly solvent systems and higher cost economics, which negatively impacts the scale-up of the process.

WO2014180979 discloses a process for the synthesis of 5-hydroxymethylfurfural (HMF) from saccharides. In particular, it has been found that it is possible to obtain monosaccharide (hexose) having 6 carbon atoms, disaccharides derived therefrom, oligosaccharides and polysaccharides derived therefrom in order to obtain high purity 5-hydroxymethyl furfural (HMF) A dehydration method is disclosed.

Prior art methods disclose the use of various catalyst and solvent systems for the synthesis of 5-HMF via microwave assist as well as conventional means. Obviously, these methods are associated with problems with the use of non-eco-friendly solvents with higher cost economics, responsive performance, longer reaction times, catalyst and product separation, lower catalyst activity, lower selectivity & yield, and environmental risks do.

Thus resulting in higher selectivity and yield; There has been a need in the prior art for a method for the synthesis of 5-HMF, which has the advantage of having higher conversion rates with improved catalyst stability, ease of product separation, and most importantly, the ability to recycle catalysts at 100% recovery.

SUMMARY OF THE INVENTION

The present invention relates to a process for preparing a reaction mixture comprising: a) contacting a sugar with a single-phase organic solvent to obtain a reaction mixture; And b) treating the reaction mixture in the presence of an acid catalyst to a temperature in the range of from 100 ° C to 180 ° C for a time ranging from 0.5 minutes to 4.0 hours to obtain at least 70% conversion of the sugar to a single furan derivative, Wherein the catalyst is selected from the group consisting of homogeneous acid catalysts, heterogeneous solid acid catalysts, and combinations thereof.

The present invention also relates to a process for the preparation of a compound of formula I, which comprises contacting a sulfonating agent with a polymer in the presence of an organic solvent to obtain a reaction suspension; Stirring the reaction suspension at a temperature in the range of 35 占 폚 to 100 占 폚 for a time in the range of 30 minutes to 4 hours to obtain a suspension of the heterogeneous acid catalyst; And isolating a suspension of the heterogeneous acid catalyst to obtain a heterogeneous solid acid catalyst.

These and other features, aspects, and advantages of the subject matter of the present invention will be better understood with reference to the following detailed description and claims. This summary is provided to introduce the selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter and is not intended to be used to limit the scope of the subject matter claimed.

Those skilled in the art will appreciate that variations and modifications other than those specifically described may be made by the present invention. It is to be understood that the invention includes all such variations and modifications. The invention also includes all steps, features, compositions and compounds individually or collectively referred to or indicated herein, and any and all combinations of any of these steps or features.

Justice:

For convenience, before further description of the present invention, specific terms used in the specification and examples are collected here. These definitions are to be interpreted in the light of the remainder of the present invention and should be understood by those of ordinary skill in the relevant arts. The terms used herein have the same meaning as commonly understood by one of ordinary skill in the art, but for convenience and completeness, specific terms and their meanings are set forth below.

The singular expressions are used for grammatical purposes to refer to one or more than one (i. E., At least one).

The terms " comprises "and" comprising "are used in a generic, open sense and may include additional elements. Throughout this specification, unless the context requires otherwise, the terms " comprises "and variations thereof, such as" comprising "and" comprising "refer to the inclusion of a stated element or step, It will be understood that they do not imply inclusion of any other element or step, or group of elements or steps.

The term "comprising" is used to mean "including, but not limited to. "Including" and "including but not limited to" may be used interchangeably.

As used herein, the term "DIC _A T" refers to the solid acid catalyst disclosed in the present invention and developed at the DBT-ICT center of the Institute of Chemical Technology, Energy Biosciences. The various solid acid catalysts prepared by using different polymeric supports and disclosed in the present invention and further disclosed herein are as follows:

DIC _A T-1: DBT-ICT-CEB catalyst prepared by using polyvinyl alcohol

DIC _A T-2: DBT-ICT-CEB catalyst prepared by using cellulose

DIC _A T-3: DBT-ICT-CEB catalyst prepared by using a hydroxyacrylate polymer

The term "saccharide" as used herein refers to a saccharide having a composition according to the formula (CH ₂ O) _n consisting of monosaccharide, disaccharide and / or polysaccharide. The term "saccharide" may be used interchangeably with the term "saccharide" herein.

Concentrations, concentrations, amounts, and other numerical data may also be expressed herein in a range format. It should be understood that such a range format is used merely for convenience and brevity, and includes not only explicitly recited numerical values as the boundaries of the range, but also all numbers and sub-ranges included within the range as if each numerical value and sub- Should be interpreted flexibly to include individual values or sub-ranges. For example, the temperature range from about 70 ° C to about 180 ° C includes not only the explicitly listed boundaries of from about 70 ° C to about 180 ° C, but also includes sub-ranges such as 90 ° C to 110 ° C, But should be construed to include individual quantities, including 82 ° C, 121.6 ° C, and 168.3 ° C, including the fractional amounts within the specified ranges.

As mentioned above, the process for the synthesis of 5-hydroxymethylfurfural (5-HMF) using various catalysts and solvents via microwave assisted methods and conventional methods disclosed in the prior art has several disadvantages, Time, higher cost, catalyst and product separation, low catalyst activity, and low yield. The present invention relates to a method for synthesizing a furan derivative, more particularly 5-hydroxymethylfurfural (5-HMF) from a saccharide by a short-time microwave assisted or conventional heating reaction by using a homogeneous or heterogeneous- . The use of an acid catalyst in a single phase organic solvent system for the synthesis of 5-HMF provides excellent catalytic activity, selectivity, conversion rate, production rate and product yield. In addition, the use of a heterogeneous-solid acid catalyst, DIC _A T, in the present invention provides convenience in a simple manner of separating the catalyst from the reaction mixture. The reaction products and catalysts are readily separated from the reaction mixture by conventional methods, such as simple solvent distillation and filtration procedures.

The process for preparing the furan derivatives disclosed herein comprises the steps of: a) contacting a sugar with a mono-phase organic solvent to obtain a reaction mixture; And b) treating the reaction mixture in the presence of an acid catalyst to a temperature in the range of from 100 ° C to 180 ° C for a time ranging from 0.5 minutes to 4.0 hours to obtain at least 70% conversion of the sugar to a single furan derivative, The catalyst is selected from the group consisting of homogeneous acid catalysts, heterogeneous solid acid catalysts, and combinations thereof.

The present invention also relates to a process for the preparation of a polymer comprising the steps of: a) contacting a sulfonating agent with a polymer in the presence of an organic solvent to obtain a reaction suspension; And b) stirring the reaction suspension at a temperature in the range of 35 DEG C to 100 DEG C for a time in the range of 30 minutes to 4 hours to obtain a suspension of the heterogeneous acid catalyst; and c) isolating a suspension of the heterogeneous acid catalyst to obtain a heterogeneous solid acid catalyst.

In one embodiment, the furan derivative produced by the disclosed method is 5-hydroxymethyl furfural (5-HMF).

Saccharide is used as a substrate for the synthesis of furan derivatives. In one embodiment, the saccharide feedstocks used for the disclosed method include, but are not limited to, hexose and pentose sugars, polysaccharides including at least one hexose, corn syrup, high fructose corn syrup, , Fructose, fructose syrup, crystalline fructose, crude fructose; Refined fructose, high fructose concentrate, fructose syrup, or combinations thereof. In one embodiment, the substrate is hexose sugar. In one embodiment, the sugar is selected from the group consisting of glucose, fructose, sucrose, and combinations thereof. In another embodiment, the sugar is fructose. In one application, the form of fructose is anhydrous. In one embodiment, the sugar is in an amorphous form. In one embodiment, the sugar is in a crystalline form.

The solvent used in the process disclosed herein is a mono-phase organic solvent. In one embodiment, the solvent is selected from the group consisting of alcohols having the formula R-OH, N, N-dimethylformamide, dimethylsulfoxide, esters and 1,4-dioxane. In one embodiment, the solvent is an alcohol having the formula R-OH (wherein R is in the range of C ₁ to C ₁₅ , more preferably C ₁ to C ₄ ). In one embodiment, the C ₁ to C ₄ alcohol is selected from the group consisting of methanol, ethanol, n-propanol, iso-propanol, sec-butanol, tert-butanol and combinations thereof. In another embodiment, the C ₁ to C ₄ alcohol is isopropanol. In one embodiment, the mono-phase organic solvent has a boiling point of less than 100 < 0 > C.

The reaction mixture for the preparation of the furan derivatives includes sugar and low boiling organic solvents. In one embodiment, the concentration of sugar in the reaction mixture is in the range of 1-50% (w / v), preferably 1-10% (w / v). In one embodiment, the water content in the reaction mixture is in the range of 0 to 20%, preferably 0 to 6% w / w.

In one embodiment, the reaction is conducted at a temperature in the range of 100-180 [deg.] C. In one embodiment, in order to convert at least 70% of the reactants to the desired product, it is sufficient to bring the reaction mixture into contact with microwave radiation for a desired period of time to a temperature in the range of 100 ° C to 180 ° C. In another embodiment, in order to convert at least 90% of the reactants to the desired product, it is sufficient to bring the reaction mixture into contact with microwave radiation for a desired period of time to a temperature in the range of 100 ° C to 180 ° C.

In one embodiment, the reaction is conducted at a temperature in the range of 100-180 [deg.] C. In one embodiment, to convert at least 70% of the reactants to the desired product, it is sufficient to bring the reaction mixture into contact with a conventional heater for a desired period of time to a temperature in the range of 100 ° C to 180 ° C. In another embodiment, in order to convert at least 90% of the reactants to the desired product, it is sufficient to bring the reaction mixture into contact with a conventional heater for a desired time to a temperature in the range of 100 ° C to 180 ° C.

In one embodiment, the method of synthesis of 5-HMF is carried out in a microwave reactor, wherein the temperature is in the range of 100-180 占 폚. In another embodiment, the preferred temperature is in the range of 110-150 占 폚 under microwave heating conditions. In one embodiment, the method provides for the use of a microwave reactor having a frequency of 2.45 GHz and a power in the range of 10-400 watts. In one embodiment, the reaction mixture is stirred at a rotational speed in the range of 200-800 rpm. In another embodiment, the reaction mixture is stirred at a rotational speed in the range of 400-650 rpm. In one embodiment, the reaction is conducted under microwave heating conditions for 30-300 seconds. In another embodiment, the reaction is conducted under microwave heating conditions for 30-120 seconds.

In one embodiment, the method of synthesis of 5-HMF is carried out by conventional heating at a pressure in the range of 5-50 bar. In another embodiment, conventional heating is performed under a pressure in the range of 5-30 bar. In one embodiment, the reaction mixture is heated to a temperature in the range of 100-180 占 폚. In another embodiment, the reaction mixture is heated to a temperature in the range of 100-150 占 폚. Proportional-Integral-Derivative (PID) Heating is maintained by a temperature controller. In one embodiment, the reaction time under typical heating is in the range of 0.5-5 hours. In one embodiment, the reaction time under typical heating is in the range of 0.5-4 hours. In one embodiment, the reaction time under typical heating is in the range of 0.5-3 hours. In one embodiment, agitation of the reaction mixture is performed by a four pitch blade impeller at a rotational speed in the range of 100-800 rpm.

In one embodiment, the conversion of sugar by the methods disclosed herein ranges from 45-100%. In another embodiment, the conversion of sugar by the methods disclosed herein ranges from 95% to 100%.

In one embodiment, the yield of the furan derivative by the methods disclosed herein is in the range of 10-95%. In another embodiment, the yield of the furan derivative by the methods disclosed herein is in the range of 80-95%.

In one embodiment, the process is carried out in a batch reactor. In one embodiment, the process is carried out in a continuous reactor. In one embodiment, the process is carried out in a fixed bed reactor.

A method for producing a furan derivative from a sugar is carried out in the presence of an acid catalyst. In one embodiment, the acid catalyst is used in an amount ranging from 0.01 to 5 g per cc of the reaction mixture. In another embodiment, the acid catalyst is used in an amount ranging from 0.1 to 1.0 g per cc of the reaction mixture.

After conversion of the sugar to the furan derivative, the reaction mixture is cooled and the catalyst is separated by filtration and then reused for subsequent reaction. In one embodiment, the recycling of the catalyst is performed no more than 20 times without regeneration without the addition of fresh catalyst. In another embodiment, the recycling of the catalyst is carried out more than 20 times without regeneration without the addition of fresh catalyst. In another embodiment, the recycling of the catalyst is performed no more than five times without regeneration without the addition of fresh catalyst.

In one embodiment, the acid catalyst is a homogeneous acid catalyst. In one embodiment, the homogeneous acid catalyst is an aliphatic sulfonic acid. In one embodiment, the homogeneous acid catalyst is an aromatic sulfonic acid. In one embodiment, the aromatic sulfonic acid is selected from the group consisting of naphthalenesulfonic acid, dimethylanilinesulfonic acid, para-toluenesulfonic acid (p-TSA), ortho / meta-toluenesulfonic acid (o / m-TSA) and combinations thereof. In another embodiment, the aromatic sulfonic acid is para-toluenesulfonic acid (p-TSA).

In one embodiment, the acid catalyst is a heterogeneous solid acid catalyst. In one embodiment, the heterogeneous solid acid catalyst is a hydrophilic sulfonated solid porous matrix. In one embodiment, the heterogeneous solid acid catalyst is a DIC _A T acid catalyst.

In one embodiment, a process for preparing a heterogeneous solid acid catalyst is provided. A process for preparing a heterogeneous solid acid catalyst comprises the steps of: a) contacting a sulfonating agent with a polymer in the presence of an organic solvent to obtain a reaction suspension; And b) stirring the reaction suspension at a temperature in the range of 35 DEG C to 100 DEG C for a time in the range of 30 minutes to 4 hours to obtain a suspension of the heterogeneous acid catalyst; c) isolating a suspension of the heterogeneous acid catalyst to obtain a heterogeneous solid acid catalyst.

In one embodiment, the sulfonating agent is selected from the group consisting of chlorosulfonic acid, sulfuric acid, sulfur trioxide, and combinations thereof. In one embodiment, the sulfonating agent is chlorosulfonic acid.

In one embodiment, the heterogeneous solid acid catalyst is comprised of a hydrophilic functionalized polymer. In one embodiment, the functionalized polymer has a surface area in the range of 5-200 m ² / g. In another embodiment, the functionalized polymer has a surface area in the range of 5-50 m ² / g, a pore size in the range of 2-50 nm, an acidity in the range of 0.5-10 mmol / g, a void volume in the range of 0.022-2.0 cc / g . In one embodiment, the molecular weight of the polymer is in the range of 3-23 kDa, the particle size is in the range of 10-300 [mu] m, and the hydroxy value is in the range of 1-20 mg / g. In one embodiment, the polymer is a single linear polymer. In one embodiment, the polymer is a crosslinked polymer. In one embodiment, the polymer used is in crystalline form. In one embodiment, the polymer used is an amorphous form. In one embodiment, the polymer is in the form of a spherical bead.

In one embodiment, the polymer comprises a hydroxy functionality. In one embodiment, the polymer comprises an amine functionality. In one embodiment, the polymer is selected from the group consisting of cellulose, polyvinyl alcohol, polyhydroxyethyl methacrylate, polyhydroxymethyl methacrylate, polyethylene glycol, polypropylene glycol, silica, alumina, polyethyleneamine, polyamide and polyallylamine ≪ / RTI > In another embodiment, the polymer is selected from the group consisting of cellulose, polyvinyl alcohol, polyhydroxyethyl methacrylate, and polyhydroxymethyl methacrylate.

In one embodiment, sulfonation derivatization of the polymer surface to obtain a heterogeneous solid acid catalyst is carried out in the presence of an organic solvent. In one embodiment, the organic solvent is a non-nucleophilic solvent. In one embodiment, the organic solvent is selected from the group consisting of methylene dichloride, chloroform, carbon tetrachloride, ethylene dichloride, propylene dichloride, and combinations thereof.

In one embodiment, heterogeneous solid acids prepared by the methods disclosed herein for various acid catalysed organic modifications such as hydrolysis, removal, addition, substitution, condensation, esterification, protection, deprotection, Catalysts may also be used.

In one embodiment, a) contacting the fructose with isopropanol to obtain a reaction mixture; And b) treating the reaction mixture in the presence of an acid catalyst for a time of 2.0 minutes at a temperature of 120 DEG C to obtain at least 70% conversion of fructose to 5-HMF, wherein the acid catalyst is PTSA, A process for producing HMF is disclosed.

In one embodiment, a) contacting the fructose with isopropanol to obtain a reaction mixture; And b) treating the reaction mixture in the presence of an acid catalyst at a temperature of 130 캜 for a time in the range of 2.0 minutes to obtain at least 70% conversion of the fructose to 5-HMF, wherein the acid catalyst is DIC _A T , A process for producing 5-HMF is disclosed.

The invention is also illustrated by the following scheme:

Reaction 1. Synthesis of 5-HMF from fructose is as follows.

Example

The present invention will now be illustrated by way of example and these embodiments are intended to illustrate the practice of the invention and are not intended to be construed as being bound by any limitation to the scope of the invention. Other embodiments within the scope of the invention are also possible.

Example  One

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of isopropyl alcohol in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes to obtain a reaction suspension. To this reaction suspension under continuous stirring was added 0.1 gm / cc of an acid catalyst (provided in Table 1). The resulting reaction mixture was heated to 120 < 0 > C by treatment with microwave radiation for 120 seconds under stirring. After 120 seconds, the reaction material was cooled to room temperature. HPLC analysis of a sample demonstrating 84-94% molar yield of HMF and 97-98% fructose conversion was obtained. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 1 given below gives the HMF yield and fructose conversion in different acid catalysts using the methods described above.

<Table 1>

Example  2

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of a solvent (provided in Table 2) in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes to obtain a reaction suspension. 0.1 gm / cc of the acid catalyst (PTSA) was added to the reaction suspension under continuous stirring. The resulting reaction material was heated by treatment with microwave radiation under stirring for 120 seconds. After 120 seconds, the reaction mixture was cooled to room temperature. HPLC analysis of a sample demonstrating 76-88% molar yield of HMF and 80-99% fructose conversion was obtained. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 2 given below gives the HMF yield and fructose conversion in the different solvents using the methods described above.

<Table 2>

Example  3

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of isopropyl alcohol in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. This reaction suspension was charged with the desired amount of PTSA (provided in Table 3) under stirring. The resulting reaction material was heated by treatment with microwave radiation for 90 seconds. After 90 seconds, the reaction material was cooled at room temperature. HPLC analysis of a sample demonstrating 74-88% molar yield of HMF and 94-98% fructose conversion was obtained. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 3 given below gives the HMF yield and fructose conversion at various acid catalyst concentrations using the methods described above.

<Table 3>

Example  4

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of isopropyl alcohol in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. This reaction suspension was charged with 0.10 gm / cc PTSA under stirring. The resulting reaction material was heated to 120 &lt; 0 &gt; C by treatment with microwave radiation for a desired period of time (provided in Table 4). Thereafter, the reaction material was cooled to room temperature. HPLC analysis of samples demonstrating 32-91% molar yield of HMF and 50-100% fructose conversion was obtained. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 4 given below gives the HMF yield and fructose conversion at various reaction times using the methods described above.

<Table 4>

Example  5

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of a solvent (provided in Table 5) in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. The desired amount of acid catalyst (DIC _A T-1) was added to the reaction suspension under stirring. The resulting reaction mixture was heated by treatment with microwave radiation under stirring for 120 seconds. After 120 seconds, the reaction material was cooled to room temperature and the catalyst was removed by vacuum filtration. The obtained sample demonstrated a 50-94% molar yield of HMF and a fructose conversion of 80-99% by HPLC analysis. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 5 below provides the HMF yield and fructose conversion in various reaction solvents using the methods described above.

<Table 5>

Example  6

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of a solvent (provided in Table 6) in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. The desired amount of acid catalyst (DIC _A T-3) was added to the reaction suspension under stirring. The resulting reaction mixture was heated by treatment with microwave radiation under stirring for 120 seconds. After 120 seconds, the reaction material was cooled to room temperature and the catalyst was removed by vacuum filtration. The obtained sample demonstrated a 50-94% molar yield of HMF and a fructose conversion of 80-99% by HPLC analysis. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 6 given below provides the HMF yield and fructose conversion in various reaction solvents using the methods described above.

<Table 6>

Example  7

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of a solvent (provided in Table 6) in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. The reaction suspension was charged with the desired amount of acid catalyst (DIC _A T-3) (provided in Table 6). The resulting reaction material was heated by treatment with microwave radiation under stirring for 120 seconds. After 120 seconds, the reaction material was cooled to room temperature and the catalyst was removed by vacuum filtration. HPLC analysis of the samples demonstrated a 61-93% molar yield of HMF and 97-100% fructose conversion. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 7 below provides HMF yield and fructose conversion at various catalyst DIC _A T-3 concentrations using the methods described above.

<Table 7>

Example  8

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of isopropyl alcohol in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. This reaction suspension was charged with 0.11 gm / cc of an acid catalyst (DIC _A T-3) under stirring. The resulting reaction material was heated to 130 DEG C by treatment with microwave radiation for a desired period of time (provided in Table 8) under continuous agitation. After completion of the reaction, the reaction material was cooled at room temperature and the catalyst was removed by vacuum filtration. The obtained sample demonstrated a 50-92% molar yield of HMF and 98-100% fructose conversion by HPLC analysis. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 8 below provides HMF yield and fructose conversion at various reaction times.

<Table 8>

Example  9

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of crystalline fructose was added to 8 ml of isopropyl alcohol in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. This reaction suspension was charged with 0.11 gm / cc of an acid catalyst (DIC _A T-3) under stirring. The resulting reaction material was heated to the desired temperature (provided in Table 9) by treatment with microwave radiation for 120 seconds under continuous stirring. After completion of the reaction, the reaction material was cooled at room temperature and the catalyst was removed by vacuum filtration. The obtained sample demonstrated 21-93% molar yield of HMF and 73-100% fructose conversion by HPLC analysis. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 9 below provides HMF yield and fructose conversion at various reaction temperatures using the methods described above.

<Table 9>

Example  10

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. Adding the desired amount of crystalline fructose (as shown in Table 10) to the required amount of solvent in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. This reaction suspension was charged with 0.11 gm / cc of an acid catalyst (DIC _A T-3) under stirring. The resulting reaction material was heated to 130 &lt; 0 &gt; C by treatment with microwave radiation for 120 seconds under continuous stirring. After completion of the reaction, the reaction material was cooled at room temperature and the catalyst was removed by vacuum filtration. The obtained sample demonstrated a 26-92% molar yield of HMF and 99-100% fructose conversion by HPLC analysis. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 10 below provides the HMF yield and fructose conversion at various fructose concentrations using the methods described above.

<Table 10>

Example  11

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. To a required amount of solvent (16 ml) in a 20 ml sealed glass tube with magnetic stirrer was added 1 gm of the desired substrate (shown in Table 11); And the mixture was stirred at room temperature for 5 minutes. This reaction suspension was charged with 0.11 gm / cc of an acid catalyst (DIC _A T-3) under stirring. The resulting reaction material was heated to 130 &lt; 0 &gt; C by treatment with microwave radiation for 120 seconds under continuous stirring. After completion of the reaction, the reaction material was cooled to room temperature and the catalyst was removed by vacuum filtration. The obtained sample demonstrated a 48-93% molar yield of HMF and 99-100% fructose conversion by HPLC analysis. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 11 given below provides the HMF yield and fructose conversion at various substrates using the methods described above.

<Table 11>

Example  12

Experiments were conducted in a batch mode operation under microwave heating at a frequency of 2.45 GHz. 1 gm of fructose was added to the required amount of solvent (16 ml) in a 20 ml sealed glass tube with magnetic stirrer; And the mixture was stirred at room temperature for 5 minutes. The reaction suspension was charged with 0.11 gm / cc of the acid catalyst (DIC _A T-1) under stirring. The resulting reaction material was heated to 130 &lt; 0 &gt; C by treatment with microwave radiation for 120 seconds under continuous stirring. After completion of the reaction, the reaction material was cooled to room temperature and the catalyst was removed by vacuum filtration and the catalyst was recycled for subsequent run (provided in Table 12). The resulting filtrate sample was analyzed by HPLC, which demonstrated 94-95% molar yield of HMF and 98-99% fructose conversion. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 12 below provides the HMF yield and the fructose conversion rate in the number of catalyst recycles using the method described above.

<Table 12>

Example  13

Experiments were carried out in a batch-wise operation under conventional heating in a 300 ml Parr pressure reactor autoclave assembly with a four-pitch wing amp and a PID thermostat with an accuracy of 占 1 占 폚. The autoclave was loaded with 2 gm of crystalline fructose in the desired amount of solvent (32 ml) and the desired acid catalyst DIC _A T (provided in Table 13). The reactants in the autoclave were stirred at room temperature for 5 minutes and then nitrogen purged 2-3 times. The autoclave was pressurized to 15 kg / cm &lt; ³ &gt; under nitrogen and the reaction material was heated for 120 minutes under constant stirring. After 120 minutes of reaction, the reaction was cooled to room temperature and finally the nitrogen pressure was released. The heterogeneous catalyst in the reactants was removed by vacuum filtration. Samples from this filtrate were analyzed by HPLC, demonstrating 68-90% molar yield of HMF and 96-98% fructose conversion. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 13 given below provides the HMF yield and fructose conversion in various acid catalysts using the methods described above.

<Table 13>

Example  14

All experiments were performed in a 300 ml Parr pressure reactor autoclave assembly with a four-pitch wing amp and a PID thermostat with an accuracy of plus or minus 1 ° C under aseptic working under conventional heating. The autoclave was loaded with 2 gm of crystalline fructose in the desired amount of solvent (32 ml) and the desired acid catalyst DIC _A T-3. The reactants in the autoclave were stirred at room temperature for 5 minutes and then nitrogen purged 2-3 times. The desired pressure (provided in Table 14) was obtained by using nitrogen gas and the reaction mass was heated for 120 minutes under stirring and then the sample was removed at the desired time intervals. After 120 minutes, the reaction material was cooled to room temperature and nitrogen pressure was released. The heterogeneous catalyst was removed by vacuum filtration. Samples from this filtrate were analyzed by HPLC and demonstrated a 40-90% molar yield and 60-100% fructose conversion of HMF. The solvent was then removed by vacuum distillation to give a dark brown viscous oil of crude HMF.

Table 14 below provides HMF yield and fructose conversion at various pressures using the methods described above.

<Table 14>

Example  15

All experiments were performed in a 300 ml Parr pressure reactor autoclave assembly with a four-pitch wing amp and a PID thermostat with an accuracy of plus or minus 1 ° C under aseptic working under conventional heating. The autoclave was loaded with 2 gm of crystalline fructose in the desired amount of IPA (32 ml) and the desired acid catalyst DIC _A T-3. The reactants in the autoclave were stirred at room temperature for 5 minutes and then nitrogen purged 2-3 times. A desired nitrogen pressure of 15 kg / cm &lt; ³ &gt; was used and the reactants were heated under constant agitation for a desired time (provided in Table 15). After completion of the reaction, the reaction material was cooled at room temperature and nitrogen pressure was released. The heterogeneous catalyst was removed from the reactants by vacuum filtration. Samples from this filtrate were analyzed by HPLC and showed 30-90% molar yield of HMF and 60-100% fructose conversion. The solvent was removed by vacuum distillation to obtain a dark brown viscous oil of crude HMF.

Table 15 given below provides the HMF yield and fructose conversion at various times using the methods described above.

<Table 15>

Example  16

_A heterogeneous solid acid catalyst, DIC _A T, was prepared by sulfonation anchoring on the aliphatic hydroxy group of the hydrophilic polymer via organic linkages. _A typical experimental procedure for the preparation of DIC _A T is as follows:

The reaction was carried out in a 4 neck 250 ml dry round bottomed flask with heating oil bath, reflux condenser, thermometer pocket, addition funnel and overhead stirrer. 1 gm of a hydroxy polymer (polyvinyl alcohol) was added under a nitrogen blanket. 10 ml of ethylene dichloride was charged to the flask under slow stirring. 9.5 ml of sulfonating agent (chlorosulfonic acid) was added dropwise over 30 minutes via an addition funnel under vigorous stirring. After completion of the addition reaction, the reaction material was vigorously stirred at room temperature for 20-30 minutes and then heated to reflux for 1 hour. Upon completion of the 1 hour reflux, the reaction material is cooled to room temperature and then cooled to 0 &lt; 0 &gt;C; Then 10 ml of aqueous methanol was slowly added via an addition funnel over 30 minutes and maintained at 0 [deg.] C for an additional 30 minutes under vigorous stirring. The resulting black solid was filtered by suction pump and washed with cold water until chlorine removal from the filtrate tested by the AgNO ₃ precipitation test. Finally, the solid cake was suction dried by suction pump and maintained at 70-80 &lt; 0 &gt; C under vacuum for drying. The resulting black dry powder of DIC _A T was used for the reaction.

Example  17

Synthesis of HMF in a packed bed reactor was performed in a 2 x 20 cm high steel column with heating jacket with inlet outlet temperature sensor and pressure regulating valve. The 5 cm catalyst layer was filled with a sufficient amount of inert material. Prior to passing the substrate through the packed bed column, the column was pre-equilibrated by passing 2-5 column volumes (CV) of fresh water and IPA to obtain a column temperature of 120 ° C and a pressure of 10-15 kg / cm ³ . 100 ml of a 6.25% Fructose solution in preheated IPA was passed through a catalyst bed maintained at 120 占 폚 by conventional heating at a desired flow rate in a cyclic loop by a dual piston pressure pump. Simultaneously, samples from the reaction mixture were removed at different time intervals for in-process HPLC analysis. Once the required HMF yield and Fructot conversion were achieved, the substrate flow was stopped and the catalyst layer was washed with 2 CV of fresh IPA to remove the line and leaving the catalyst layer intact. The resulting complex fraction was analyzed by HPLC and the results were in the range of 88-94% HMF yield and 95-100% fructose conversion.

Example  18

Synthesis of HMF in a packed bed reactor was performed in a 2 x 20 cm high steel column with heating jacket with inlet outlet temperature sensor and pressure regulating valve. The 5 cm catalyst layer was filled with a sufficient amount of inert material. Prior to passing the substrate through the packed bed column, the column was pre-equilibrated by passing 2-5 column volumes (CV) of fresh water and IPA to obtain a column temperature of 120 ° C and a pressure of 10-15 kg / cm ³ . 100 ml of a 6.25% Fructose solution in preheated IPA was passed through a catalyst bed maintained at 120 占 폚 by microwave heating at a desired flow rate in a cyclic loop by a dual piston pressure pump. Simultaneously, samples from the reaction mixture were removed at different time intervals for in-process HPLC analysis. Once the required HMF yield and Fructot conversion were achieved, the substrate flow was stopped and the catalyst layer was washed with 2 CV of fresh IPA to remove the line and leaving the catalyst layer intact. The resulting complex fraction was analyzed by HPLC and the results were in the range of 88-94% HMF yield and 95-100% fructose conversion.

Advantages obtained in an exemplary method within the subject of the present invention

The present invention relates to a process for preparing 5-hydroxymethylfurfural (5-HMF) from a saccharide using an acid catalyst. The acid-catalyzed cyclodextration process for the synthesis of 5-HMF provides a simple and cost-effective route for the preparation of 5-HMF in mono-phase organic solvents. The heterogeneous solid acid catalyst, DIC _A T, used in the process disclosed herein has excellent catalytic activity, stability and selectivity for the desired product. Due to the higher selectivity of the catalyst, the formation of by-products such as polymers, cumene, levulic acid and condensation products is significantly reduced. The entire process uses a single phase organic solvent (low boiling or high boiling point) which is easily separated by minimal energy use for solvent distillation. The process is carried out at considerably reduced reaction times through conventional or microwave auxiliary heating, resulting in increased productivity.

The present invention involves a microwave assisted short-time reaction carried out in a single phase organic solvent at a temperature range of 100-180 DEG C, thus providing process viability using low energy consumption at an economical cost. A short reaction time of 30-120 seconds improves bulk manufacture and economics of 5-HMF production within a given time.

The 5-HMF synthesis method of the present invention involves low energy use while producing minimal waste and effluent.

Thus, the disclosed method results in higher selectivity and yield; It is an eco-friendly and efficient method with improved catalyst stability and higher conversion rate, ease of separation and most importantly the advantage of catalyst recycling at 100% recovery.

While the subject matter of the invention has been described in considerable detail with reference to specific embodiments thereof and embodiments thereof, other embodiments are possible. That is, the intent and scope of the appended claims should not be limited to the description of the preferred embodiments and embodiments contained herein.

Claims (12)

a) contacting the sugar with a monophasic organic solvent to obtain a reaction mixture; And
b) treating the reaction mixture in the presence of an acid catalyst to a temperature in the range of from 100 ° C to 180 ° C for a period of time ranging from 0.5 minutes to 4.0 hours to obtain at least 70% conversion of the sugar to the single furan derivative
Wherein the acid catalyst is selected from the group consisting of homogeneous acid catalysts, heterogeneous solid acid catalysts, and combinations thereof.
Lt; / RTI &gt; The method according to claim 1, wherein the sugar is selected from the group consisting of glucose, fructose, sucrose, and combinations thereof, preferably fructose. The process of claim 1, wherein the mono-phase organic solvent is selected from the group consisting of C ₁ to C ₁₅ alcohols, preferably methanol, ethanol, n-propanol, iso-propanol, sec-butanol, tert- C ₁ to C ₄ alcohols, preferably iso-propanol. 3. The catalyst according to claim 1, wherein the homogeneous acid catalyst is selected from the group consisting of naphthalenesulfonic acid, dimethylanilinesulfonic acid, para-toluenesulfonic acid (p-TSA), ortho / meta-toluenesulfonic acid (o / m- TSA) Is an aromatic sulfonic acid selected from para-toluenesulfonic acid (p-TSA). The method of claim 1, wherein the heterogeneous solid acid catalyst is a hydrophilic sulfonated solid porous matrix. The process according to claim 1, wherein the acid catalyst is used in an amount ranging from 0.01 to 5 g per cc of the reaction mixture, preferably from 0.1 to 1.0 g per cc of the reaction mixture. The method according to claim 1, wherein the furan derivative is obtained by a microwave auxiliary heating method or a conventional heating method. The method of claim 1, wherein the furan derivative is 5-hydroxymethyl furfural (5-HMF). a. Contacting the sulfonating agent with a polymer in the presence of an organic solvent to obtain a reaction suspension;
b. Stirring the reaction suspension at a temperature in the range of 35 占 폚 to 100 占 폚 for a time in the range of 30 minutes to 4 hours to obtain a suspension of the heterogeneous acid catalyst; And
c. Isolating a suspension of the heterogeneous acid catalyst to obtain a heterogeneous solid acid catalyst
The method of producing a heterogeneous solid acid catalyst according to claim 1, The method of claim 9, wherein the sulfonating agent is selected from the group consisting of chlorosulfonic acid, sulfuric acid, sulfur trioxide, and combinations thereof, preferably chlorosulfonic acid. The method of claim 9, wherein the polymer is selected from the group consisting of cellulose, polyvinyl alcohol, polyhydroxyethyl methacrylate, polyhydroxymethyl methacrylate, polyethylene glycol, polypropylene glycol, silica, alumina, polyethyleneamine, polyamide, polyallylamine , Preferably selected from the group consisting of cellulose, polyvinyl alcohol, polyhydroxyethyl methacrylate and polyhydroxymethyl methacrylate. 10. The process of claim 9, wherein the organic solvent is selected from the group consisting of methylene dichloride, chloroform, carbon tetrachloride, ethylene dichloride, propylene dichloride, and combinations thereof.