CLACENS JEAN MARC (CN)
DECAMPO FLORYAN (CN)
CENTRE NAT RECH SCIENT (FR)
| CN102399203A | 2012-04-04 |
ZHANG, ZEHUI ET AL.: "Catalytic conversion of carbohydrates into 5-hydroxymethylfurfural by germanium(IV) chloride in ionic liquids", CHEMSUSCHEM, vol. 4, 2011, pages 131 - 138
ZHANG, YANMEI E ET AL.: "Molecular aspects of glucose dehydration by chromium chlorides in ionic liquids", CHEM. EUR. J., vol. 17, 2011, pages 5281 - 5288
| WHAT IS CLAIMED IS: 1. Process for the production of 5-hydroxymethylfurfural from a compound of formula (I) or its corresponding cyclic five-membered structure, via a catalytic dehydration reaction in the presence of catalyst of formula (II) Formula (I): wherein : R1 is H or OH R2 is H or OH - Formula (II): M [RF-S02-N-S02-R'F]n (II) wherein: RF and R'F, which are identical or different, each represent a perhalogen radical; and - M is H or a metal element chosen from alkali metal, alkali earth metal, transition metal and lanthanide metal n is an integer equal to the valence of M. 2. A process according to claim 1, wherein the compound of formula (I) is chosen in the group consisting of: D-glucose and D-fructopyranose. 3. A process according to claim 1 or 2, wherein concentration of compound of formula (I) is comprised between 0.001 and 10 mol.L"1, when a solvent is used in the reaction medium. 4. A process according to anyone of claims 1 to 3, wherein metal elements of the periodic table are in the group consisting of: alkali metals, such as K or Cs, alkaline earth metals, such as Ca, - lanthanides, such as La or Ce, and transition metals, such as Ti, Y, Zn, Cu or Fe. 5. A process according to anyone of claims 1 to 4, wherein catalyst is chosen in the group consisting of: H(NTf2), K(NTf2), Y(NTf2)3, La(NTf2)3, Zn(NTf2)2, Cs(NTf2), Ca(NTf2)2, Fe(NTf2)3, Cu(NTf2)2, Ti(NTf2)4 and Ce(NTf2)3. 6. A process according to anyone of claims 1 to 3, wherein catalyst is a combination of H(NTf2) and Cu(NTf2)2. 7. A process according to anyone of claims 1 to 6, wherein the catalyst loading during the reaction is comprised between 0.01 and 100 mol%, in relation with the molar amount of the compound of formula (I). 8. A process according to anyone of claims 1 to 7, wherein the catalyst is a catalyst-ligand complex. 9. A process according to anyone of claims 1 to 8, wherein a solvent is used in the reaction medium. 10. A process according to claim 9, wherein the solvent is a polar aprotic solvent, selected among: linear ethers or cyclic ethers, - esters, nitriles, acetonitriles, benzonitriles, nitrate derivatives, amides, sulfones, and - sulfoxides. 1 1. Process according to anyone of claims 1 to 10, wherein the temperature of the reaction is comprised between 0 and 300°C. 12. 5-hydroxymethylfurfural susceptible to be obtained according to the process of claims 1 to 1 1. |
The present invention concerns a process for the production of 5- hydroxymethylfurfural (HMF) from a hexose via a catalytic dehydration reaction in the presence of bis(perfraoroalkylsulfonimide) acid or salts thereof catalysts, and derivatives.
PRIOR ART
5-Hydroxymethylfurfural (HMF) is a biomass-derived compound that can be applied to the synthesis of precursors of pharmaceuticals, furanose-based polymers, monomers of polymers such as polyamide, and other organic intermediates that can lead to numerous chemical products. As example, oxidation routes of HMF to 2,5-furandicarboxylic acid (FDCA) are well known.
The synthesis of HMF through acid-catalyzed dehydration of monosaccharides has been known for many years. In this respect, many researchers have widely studied the synthesis of HMF from hexose in the past decades. Various types of acid catalysts have been employed in the dehydration reaction, such as mineral acids, for example, sulfuric, hydrochloric, phosphoric acid, and organic acids, for example, citric acid, maleic acid, acetic acid, etc. In spite of simple process, easy operation, low investment, and improving the yield of HMF to a certain extent by using mineral acids as catalysts, they suffer from some limitations in consideration of equipment corrosion, recycling, and difficulties in separation. Solid acid catalysts, for example, ion exchange resin, H-zeolite, metal sulfated, zirconium phosphate, niobic acid, and niobium phosphate overcome some restrictions of mineral acids mentioned above. Nevertheless, solid acid catalysts also possess some drawbacks because of relatively lower fructose conversions and longer reaction times.
The catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF) was investigated by using various rare earth metal trifluoromethanesulfonates, that is, Yb(OTf) 3 , Sc(OTf) 3 , Ho(OTf} 3> Sm(OTf) 3 , Nd(OTf) 3 as catalysts in DMSO in Carbohydrate Research 346 (2011) 982-985. However, even the best of this catalyst such as Sc(OTf) 3 provides an insufficient HMF yield and a generation of formic acid resulting from the reaction of HMF with water.
It exists then a need to provide a new generation of environmentally-friendly catalysts to produce HMF permitting then to shift from conventional petrochemical feedstocks towards biomass-based feedstocks, with a better yield and a good reaction selectivity while avoiding the generation of formic acid in the medium.
INVENTION
It appears now that the use of particular bis(perfluoroalkylsulfonimide) acid or salts thereof on hexoses permits to produce 5-hydroxymethylfurfural (HMF) with a high yield and a very low generation of formic acid. Moreover, the reaction is efficient with a catalyst loading that remains relatively low.
The present invention concerns then a process for the production of 5- hydroxymethylfurfural (HMF) from a compound of formula (I) or its corresponding cyclic five-membered structure, via a catalytic dehydration reaction in the presence of catalyst of formula (II) Formula (I):
wherein :
R 1 is H or OH
R 2 is H or OH
Formula (II):
M [RF-S0 2 -N-S0 2 -R'F] n (II)
wherein:
RF and R'F, which are identical or different, each represent a perhalogen radical; and
M is H or a metal element chosen from alkali metal, alkali earth metal, transition metal and lanthanide metal
n is an integer equal to the valence of M.
The present invention also concerns a HMF susceptible to be obtained according to the process of the invention.
Dehydration reaction of the present invention is defined as a chemical reaction that involves the loss of water from the reacting molecule. Dehydration reactions are a subset of elimination reactions involving one or several hydroxyl group(s) (-OH). Formula (I)
Compounds of formula (I) according to the present invention is preferably chosen in the group consisting of: D-glucose and D-fructopyranose. D-fructopyranose is the cyclic six-membered structure of the D-fructose. In solution, D-fructopyranose exists as a mixture generally comprising 70% D- fructopyranose and about 22% D-fructofuranose. The open isomer D-glucose gives rise to two distinct cyclic forms: D-glucopyranose, and D- glucofuranose.
It has to be noticed that it's perfectly possible to use several compounds of formula (I) during the reaction of the present invention.
Concentration of compound of formula (I) may be comprised between 0.001 and 10 mol.L "1 , when a solvent is used in the reaction medium.
Catalyst of formula (II)
Concerning the catalyst of formula (II), RF and R'F, which are identical or different, represent a perhalogen radical, which is preferably having from 1 to 12 carbon atoms. Halogen atoms in the perhalogen radicals may be for example F or CI. Preferably RF and R'F, which are identical or different, represent CF 3 .
Metal elements of the periodic table may be chosen in the group consisting of:
alkali metals, such as K or Cs,
alkaline earth metals, such as Ca,
lanthanides, such as La or Ce, and
transition metals, such as Ti, Y, n, Cu or Fe. Metal elements M of period 4 are particularly preferred, such as Ca and Cu.
Catalysts of the present invention are preferably chosen in the group consisting of: H(NTf 2 ), (NTf 2 ) 5 Y(NTf 2 ) 3 , La(NTf 2 ) 3 , Zn(NTf 2 ) 2 , Cs(NTf 2 ), Ca(NTf 2 ) 2 , Fe(NTf 2 ) 3 , Cu(NTf 2 ) 2 , Ti(NTf 2 ) 4 and Ce(NTf 2 ) 3 .
A combination of two or more catalysts of the present invention may be used during the reaction of the present invention, notably in blend. As example, a combination of H(NTf 2 ) and Cu(NTf 2 ) 2 is particularly preferred.
Catalyst loading during the reaction may be comprised between 0.01 and 100 mol%, preferably between 1 and 30, in relation with the molar amount of the compound of formula (I).
Catalyst of the invention may be used in a homogeneous or heterogeneous way.
Catalyst may be supported on a carrier, such as for example one of the oxides, carbons or organic or inorganic resins. Notably, the carrier may be selected from the group consisting of silica, alumina, zirconia, titania, ceria, magnesia, lanthania, niobia, yttria, zeolite, perovskite, silica clay, and iron oxide and mixtures thereof. The catalyst may be supported on a carrier in any convenient fashion, particularly by adsorption, ion-exchange, grafting, trapping, impregnation, or sublimation^
Reaction of the present invention may be carried out by using a catalyst- ligand complex in which catalyst is the compound of formula (II). Although there are no particular restrictions on the ligand in the present invention provided it is a Lewis base having the ability to coordinate to a catalyst of formula (II), ligand is preferably chosen in the family of carbene ligand, π- type ligand phosphorous ligand, oxygen ligand and nitrogen ligand. Suitable ligands to be used according to the present mvention are phosphorus ligands such as halophosphites such as fluorophosphites, phosphites, phosphinites, phosphonites, and phosphine. Monodentate phosphine ligands and bidentate diphosphine ligand such as xantphos are particularly preferred.
It has to be noticed that the catalyst-ligand complex may be prepared before the start of the reaction of the present invention or in situ at the start or during the reaction.
Solvent
The process of the present invention may be carried out without solvent. It is also possible to use a solvent or a combination of solvents for the reaction, preferably solvents able to dissolve the compound of formula (I) and also solvent able to dissolve the compound of formula (I) and the compound of formula (II). Preferred solvents used in the reaction medium of the present invention are polar aprotic solvent, more preferably selected among:
linear ethers, such as diethylether, dimethoxyethane or cyclic ethers, such as tetrahydrofuran, dioxane or dimethyltetrahydrofuran,
esters, such as methyl or ethyl formate, propylene or ethylene carbonate, or butyrolactones,
nitriles, acetonitriles, benzonitriles,
nitrate derivatives, such as nitromethane or nitrobenzene,
amides, such as dimethylformamide, diethylformamide and N- methylpyrolidone, sulfones, such as dimethyl sulfone, tetramethylene sulfone and other sulfolanes.
sulfoxides, such as DMSO. Notably, when the medium of the reaction comprises a polar aprotic solvent, said medium comprises less than 10 wt % of water, notably at the start of the reaction.
Parameters
The temperature at which reaction is performed may vary in a large range, but in general it is preferred that the reaction is carried out at a temperature from 0 and 300°C, more preferably between 50 and 150°C. Temperatures may be reached either thermically or by microwave irradiation. Pressure range of the reaction may be comprised between 1 and 100 bar. Reaction of the present invention may be carried out for a range time comprised between 10 min to 24 hours.
This reaction may be conducted in any conventional equipment suitable to effect production of HMF. This reaction may be carried out in a continuous or a discontinuous fashion. For example, suitable equipments include a stirred tank or loop reactor.
End of reaction may be carried out by stop of the temperature and cooling of the reaction medium, notably air cooling.
The efficiency of the process of the present invention can be monitored by any conventional analytical means, such as Infrared spectroscopy, NMR, Raman spectroscopy, GC and HPLC. At the end of the reaction, catalysts may be eventually neutralized and/or removed by distillation, extraction or washings. Said catalysts may notably be recycled to the reactor.
HMF of interest can be purified by well known methods of the technical field, such as distillation, crystallization, liquid extraction or extraction with a polymer to adsorb HMF. The examples provided here further describe and demonstrate embodiments of the present invention. The examples are given solely for the purpose of illustration and are not to be construed as limitation of the present invention
EXPERIMENTAL PART
Example 1: D-fructose
5 mol% of different catalysts are blended with 0.2 mol.L "1 of D-fructose in DMSO. Reaction occurs under microwave irradiation at a temperature of 120°C for 1 hour. Results determined by H NMR analysis (with biphenyl as internal reference) are mentioned in Table 1 :
Table 1
It appears then that the use of the following catalysts H(NTf 2 ), Zn(NTf 2 ) 2 , Cs(NTf 2 ),Ca(NTf 2 ) 2 , Fe(NTf 2 ) 3 , Ce(NTf 2 ) 3 and Cu(NTf 2 ) 2 permits to provide a better yield (68-87%), in comparison with the best described triflate Sc(OTf) 3 (67%).
Example 2: Ligands
5 mol% of different catalysts are blended with 0.2 mol.L "1 of D-fructose in DMSO and 5 mol % of xantphos ligand [4,5-Bis(diphenylphosphino)-9,9- dimethylxanthene]. Reaction occurs under microwave irradiation at a temperature of 120°C for 1 hour.
Results determined by l R NMR analysis (with biphenyl as internal reference) are mentioned in Table 2 :
Table 2
It appears then that a diphosphine ligand such as Xantphos is efficiently activating Ti(NTf 2 ) 4 and Cu(NTf 2 ) 2 that permits to provide a higher yield to the reaction while avoiding generation of formic acid.