Names | |
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Preferred IUPAC name Furan-2,5-dicarboxylic acid | |
Other names Dehydromucic acid | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.019.819 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C6H4O5 | |
Molar mass | 156.093 g·mol−1 |
Appearance | White solid |
Density | 1.604 g/cm3 |
Melting point | 342 °C (648 °F; 615 K) |
Boiling point | 420 °C (788 °F; 693 K) |
soluble in DMSO | |
Acidity (pKa) | 4.38, 5.85 [1] |
Hazards | |
Flash point | 207 °C (405 °F; 480 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
2,5-Furandicarboxylic acid (FDCA) is an organic chemical compound consisting of two carboxylic acid groups attached to a central furan ring. It was first reported as dehydromucic acid by Rudolph Fittig and Heinzelmann in 1876, who produced it via the action of concentrated hydrobromic acid upon mucic acid. [2] It can be produced from certain carbohydrates and as such is a renewable resource, it was identified by the US Department of Energy as one of 12 priority chemicals for establishing the “green” chemistry industry of the future. [3] Furan-2,5-dicarboxylic acid (FDCA) has been suggested as an important renewable building block because it can substitute for terephthalic acid (PTA) in the production of polyesters and other current polymers containing an aromatic moiety. [4] [5] [6]
Methods for the synthesis of the FDCA may be divided into four groups: [4]
First group is based on the acid-promoted triple dehydration of aldaric (mucic) acids. This reaction requires severe conditions (highly concentrated acids, temp > 120 °C, React time > 20h) and all the methods were non-selective with yields < 50%. [7] The process has also been patented by the French company Agro Industrie Recherches et Developpements. [8] This is also the process which DuPont and ADM are using according to patent literature. [9]
The second class of synthesis routes include the oxidation reactions of various 2,5-disubstituted furans utilizing a variety of inorganic oxidants. Several routes to FDCA via oxidation of hydroxymethylfurfural (HMF) with air over different catalysts have been reported. Oxidation of HMF under strongly alkaline conditions over noble metal catalysts gives almost quantitative formation of FDCA. [10] [11] HMF and methoxymethylfurfural (MMF) oxidation was also studied with a series of conventional metal bromide catalysts (Co, Mn, Br) used for the oxidation of para-xylene to terephthalic acid. [12] Also, the direct, one pot dehydration and oxidation of fructose to FDCA via intermediate HMF has been investigated with good selectivities, unfortunately this system does not work in water. [13]
The third class includes reactions describing the synthesis of FDCA from furfural. Furfural can be oxidized to 2-furoic acid with nitric acid and the latter was subsequently converted to its methyl ester. The ester was then converted via chloromethylation at position 5 to give 5-chloromethylfuroate. The latter was oxidized with nitric acid to form dimethyl 2,5-furandicarboxylate, which, after the alkaline hydrolysis gave FDCA in 50% yield. Andrisano reported that potassium 2-furoate, when heated up to 300 °C in a nitrogen atmosphere, underwent decarboxylation to furan with simultaneous carboxylation at position 5 to di-potassium 2,5-furandicarboxylate. [14]
FDCA has also been detected in human urine. [15] A healthy human produces 3–5 mg/day. Numerous studies were undertaken to establish the metabolism of this compound and to determine the quantity, which is produced depending on the healthiness of the human. It was demonstrated that the individual quantity of produced FDCA increased after the injection of fructose. FDCA was also detected in blood plasma. [4] Recently, the enzyme furfural/HMF oxidoreductase was isolated from the bacterium Cupriavidus basilensis HMF14. [16] This enzyme might be able to convert HMF to FDCA using molecular oxygen, although an aldehyde dehydrogenase might also play a role. A Pseudomonas putida strain that was genetically engineered to express this enzyme can completely and selectively convert HMF to FDCA. This biocatalysis is performed in water, at ambient temperature and pressure, without toxic or polluting chemicals, making it very environmentally friendly. [17] Several other enzymes have been described later, including HMFO. This flavin dependent oxidase catalyzes the three consecutive oxidations to form FDCA from HMF. [18]
DuPont has announced the production of FDCA for use in PTF. [19] [9] In 2011, Avantium was the first company to build a FDCA pilot plant in Geleen, the Netherlands. Avantium has fully proven its technology to produce FDCA in this pilot plant and the company now plans to open the world’s first commercial FDCA plant. Currently Avantium has begun the construction of a 5kt FDCA commercial plant in Delfzijl, the Netherlands. The plant will be finished at the end of 2023 with commercial production starting early in 2024. Ten offtake agreements have been signed.
FDCA is a very stable compound. Its physical properties, such as insolubility in most of common solvents and a very high melting point (it melts at 342 °C) seem to indicate intermolecular hydrogen bonding. Despite its chemical stability, FDCA undergoes reactions typical for carboxylic acids, such as halogen substitution to give carboxylic dihalides, the di-ester formation and the formation of amides. [4] All these reactions were elaborated at the end of 19th and in the beginning of 20th century. Newer methods have been described by Janda et al., who introduced the synthesis of 2,5-furandicarboxylic dichloride, by the reaction of FDCA with thionyl chloride [20] The synthesis of diethyl ester and dimethyl ester as well as the amidation as well as several other modifications have been reported. [4] The versatility of FDCA is also seen in the number of derivatives available via relatively simple chemical transformations. Selective reduction can lead to partially hydrogenated products, such as 2,5 dihydroxymethylfuran, and fully hydrogenated materials, such as 2,5 bis(hydroxymethyl)tetrahydrofuran.
The most important group of FDCA conversions is undoubtedly the polymerization. The potential applications of furan-based building blocks for polymer applications has been extensively reviewed by Gandini. [21] A notable example is polyethylene 2,5-furandicarboxylate (PEF), but also other polyesters and various polyamides and polyurethanes have been described in literature. For example, PEF is only a member of the vast poly(alkylene 2,5-furandicarboxylate) family, in which FDCA is combined with diols of variable alkyl chain length (containing up to 12 methyl groups). The longer the diol alkyl chain, the higher the molecular mobility, the lower the glass transition and melting temperature, the higher the ductility [22] [23] [24]
Amongst others like Dupont and Corbion, [25] the company Avantium claims to have developed a cost-effective route to produce FDCA and the derived polyesters. FDCA has also been applied in pharmacology. It was demonstrated that its diethyl ester had a strong anaesthetic action similar to cocaine. Dicalcium 2,5-furandicarboxylate was shown to inhibit the growth of Bacillus megatorium. Screening studies on FDCA-derived anilides showed their important anti-bacterial action. The diacid itself is a strong complexing agent, chelating such ions as: Ca2+, Cu2+ and Pb2+; it is utilized in medicine to remove kidney stones. [4] HMF is metabolized via FDCA in mammals including humans. A very diluted solution of FDCA in tetrahydrofuran is utilized for preparing artificial veins for transplantation. At the beginning of this chapter, it was mentioned that FDCA is a chemically stable compound. This property has been well benefited in industry – FDCA as most of polycarboxylic acids can be an ingredient of fire foams. Such foams help to extinguish fires in a short time caused by polar and non-polar solvents. [4] FDCA has a large potential as a replacement for terephthalic acid, a widely used component in various polyesters, such as polyethylene terephthalate (PET) and polybutyleneterephthalate (PBT). The versatility of FDCA is also seen in the number of derivatives available via relatively simple chemical transformations. Selective reduction can lead to partially hydrogenated products, such as 2,5-dihydroxymethylfuran, and fully hydrogenated materials, such as 2,5-bis(hydroxymethyl)tetrahydrofuran. Both of these latter materials can serve as alcohol components in the production of new polyester, and their combination with FDCA would lead to a new family of completely biomass-derived products. Extension of these concepts to the production of new nylons, either through reaction of FDCA with diamines, or through the conversion of FDCA to 2,5-bis(aminomethyl)tetrahydrofuran. FDCA can also serve as a starting material for the production of succinic acid, whose utility is elsewhere. [26]
The primary technical barrier in the production and use of FDCA is the development of an effective and selective dehydration process from sugars. The control of sugar dehydration could be a very powerful technology, leading to a wide range of additional, inexpensive building blocks, but it is not yet well understood. Currently, dehydration processes using hydroxymethylfurfural (HMF) as intermediate are generally non-selective, unless, immediately upon their formation, the unstable intermediate products can be transformed into more stable materials such as methoxymethylfurfural (MMF). Necessary R&D will include development of selective dehydration systems and catalysts. FDCA formation will require development of cost-effective and industrially viable oxidation technology that can operate in concert with the necessary dehydration processes. [5]
In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom bonded to two organyl groups. They have the general formula R−O−R′, where R and R′ represent the organyl groups. Ethers can again be classified into two varieties: if the organyl groups are the same on both sides of the oxygen atom, then it is a simple or symmetrical ether, whereas if they are different, the ethers are called mixed or unsymmetrical ethers. A typical example of the first group is the solvent and anaesthetic diethyl ether, commonly referred to simply as "ether". Ethers are common in organic chemistry and even more prevalent in biochemistry, as they are common linkages in carbohydrates and lignin.
Pyrrole is a heterocyclic, aromatic, organic compound, a five-membered ring with the formula C4H4NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., N-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme.
Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is mainly used as a precursor to polymers. Being polar and having a wide liquid range, THF is a versatile solvent. It is an isomer of another solvent, butanone.
Furfural is an organic compound with the formula C4H3OCHO. It is a colorless liquid, although commercial samples are often brown. It has an aldehyde group attached to the 2-position of furan. It is a product of the dehydration of sugars, as occurs in a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. The name furfural comes from the Latin word furfur, meaning bran, referring to its usual source. Furfural is only derived from dried biomass. In addition to ethanol, acetic acid, and sugar, furfural is one of the oldest organic chemicals available readily purified from natural precursors.
Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen atom. Chemical compounds containing such rings are also referred to as furans.
Mucic acid, C6H10O8 or HOOC-(CHOH)4-COOH (galactaric acid or meso-galactaric acid) is an aldaric acid obtained by nitric acid oxidation of galactose or galactose-containing compounds such as lactose, dulcite, quercite, and most varieties of gum.
Terephthalic acid is an organic compound with formula C6H4(CO2H)2. This white solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tons are produced annually. The common name is derived from the turpentine-producing tree Pistacia terebinthus and phthalic acid.
Isosorbide is a bicyclic chemical compound from the group of diols and the oxygen-containing heterocycles, containing two fused furan rings. The starting material for isosorbide is D-sorbitol, which is obtained by catalytic hydrogenation of D-glucose, which is in turn produced by hydrolysis of starch. Isosorbide is discussed as a plant-based platform chemical from which biodegradable derivatives of various functionality can be obtained.
Hydroxymethylfurfural (HMF), also known as 5-(hydroxymethyl)furfural, is an organic compound formed by the dehydration of reducing sugars. It is a white low-melting solid which is highly soluble in both water and organic solvents. The molecule consists of a furan ring, containing both aldehyde and alcohol functional groups.
Polyester is a category of polymers that contain one or two ester linkages in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in plants and insects, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. Synthetic polyesters are used extensively in clothing.
Furfuryl alcohol is an organic compound containing a furan substituted with a hydroxymethyl group. It is a colorless liquid, but aged samples appear amber. It possesses a faint odor of burning and a bitter taste. It is miscible with but unstable in water. It is soluble in common organic solvents.
2-Ethylhexanoic acid (2-EHA), commonly known as octoic acid, is the organic compound with the formula CH3(CH2)3CH(C2H5)CO2H. It is a carboxylic acid that is widely used to prepare lipophilic metal derivatives that are soluble in nonpolar organic solvents. 2-Ethylhexanoic acid is a colorless viscous oil. It is supplied as a racemic mixture.
2-Methyltetrahydrofuran (2-MeTHF) is an organic compound with the molecular formula C5H10O. It is a highly flammable, mobile liquid. It is mainly used as a replacement for Tetrahydrofuran (THF) in specialized applications for its better performance, such as to obtain higher reaction temperatures, or easier separations (as, unlike THF, it is not miscible with water). It is derived from sugars via furfural and is occasionally touted as a biofuel.
2,5-Bis(hydroxymethyl)furan (BHMF) is a heterocyclic organic compound, and is a derivative of a broader class of compounds known as furans. It is produced from cellulose and has received attention as a biofeedstock. It is a white solid, although commercial samples can appear yellowish or tan.
Methoxymethylfurfural is an organic compound derived from dehydration of sugars and subsequent etherification with methanol. This colorless liquid is soluble in a wide range of solvents including lower alcohols. The molecule is a derivative of furan, containing both aldehyde and ether (methoxymethyl) functional groups. MMF has been detected in the leaves and roots of Chilean Jaborosa magellanica (Solanaceae). It has a typical odor suggestive of maraschino cherries. MMF can be made from a wide range of carbohydrate containing feedstocks including sugar, starch and cellulose using a chemical catalytic process and is a potential "carbon-neutral" feedstock for fuels and chemicals.
Shiina esterification is an organic chemical reaction that synthesizes carboxylic esters from nearly equal amounts of carboxylic acids and alcohols by using aromatic carboxylic acid anhydrides as dehydration condensation agents. In 1994, Prof. Isamu Shiina reported an acidic coupling method using Lewis acid, and, in 2002, a basic esterification using nucleophilic catalyst.
Polyethylene furan-2,5-dicarboxylate, also named poly(ethylene furan-2,5-dicarboxylate), polyethylene furanoate and poly(ethylene furanoate) and generally abbreviated as PEF, is a polymer that can be produced by polycondensation or ring-opening polymerization of 2,5-furandicarboxylic acid (FDCA) and ethylene glycol. As an aromatic polyester from ethylene glycol it is a chemical analogue of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). PEF has been described in (patent) literature since 1951, but has gained renewed attention since the US department of energy proclaimed its building block, FDCA, as a potential bio-based replacement for purified terephthalic acid (PTA) in 2004.
Itaconic anhydride is the cyclic anhydride of itaconic acid and is obtained by the pyrolysis of citric acid. It is a colourless, crystalline solid, which dissolves in many polar organic solvents and hydrolyzes forming itaconic acid. Itaconic anhydride and its derivative itaconic acid have been promoted as biobased "platform chemicals" and bio- building blocks.) These expectations, however, have not been fulfilled.
1,2,6-Hexanetriol is a trivalent alcohol with two primary and one secondary hydroxy group. It is similar to glycerol in many respects and is used as a substitute for glycerol in many applications due to its more advantageous properties, such as higher thermal stability and lower hygroscopicity.
5-Amino-1-pentanol is an amino alcohol with a primary amino group and a primary hydroxy group at the ends of a linear C5-alkanes. As a derivative of the platform chemical furfural (that is easily accessible from pentoses), 5-amino-1-pentanol may become increasingly important in the future as a building block for biodegradable polyesteramides and as a starting material for valerolactam — the monomer for polyamides.