Synthesis method of 2,5-furandicarboxylic acid

Abstract

The present invention relates to a method for synthesizing 2,5-furandicarboxylic acid, and more particularly to a more efficient and economical method for preparing 2,5-furandicarboxylic acid having multiple functions with high purity and high yield even without using a transition metal catalyst.

Description

Technical Field

[0001] The present invention relates to a method for synthesizing 2,5-furandicarboxylic acid, and more particularly, to a more efficient and economical method for preparing 2,5-furandicarboxylic acid having multiple functions with high purity and high yield even without using a transition metal catalyst. Background Art

[0002] 2,5-furandicarboxylic acid (FDCA) is a very useful substance with various functions and is widely used in the packaging industry (polyamide, polyester, polyurethane, etc.), automobiles, pharmaceutical fields, fine chemicals, etc. In addition, since polyethylene furanoate (PEF), a bioplastic developed as a substitute for polyethylene terephthalate (PET), can be obtained from 2,5-furandicarboxylic acid (FDCA), its research value is increasing.

[0003] The method of obtaining 2,5-furandicarboxylic acid (FDCA) by oxidation of 5-hydroxymethylfurfural (HMF) is known. However, in this conventional method, since the reaction is carried out by using nitric acid of excess equivalent amount as an oxidant under very strict and delicate conditions, the generation of undesirable by-products cannot be avoided. Thereafter, a method (for example, Korean patent publication No. 10-2018-0090840 and No. 10-2018-0107143) of chemically selectively synthesizing 2,5-furandicarboxylic acid (FDCA) has been developed by utilizing a variety of transition metals such as gold, platinum, palladium, titanium, etc. and using oxygen as an oxidant. However, these methods are difficult to be industrialized due to the use of expensive transition metal catalysts, and the reaction needs to be carried out at high temperature or high pressure.

[0004] Therefore, it is necessary to develop a method for preparing 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF) with high purity and high yield using oxygen (or air) as an oxidant even without using a transition metal catalyst. Summary of the invention

[0005] Technical issues

[0006] The present invention aims to solve the above-mentioned problems existing in the prior art, and aims to provide a method for preparing 2,5-furandicarboxylic acid (FDCA) with high purity and high yield from 5-hydroxymethylfurfural (HMF) through a chemical selective oxidation reaction based on an environmentally friendly scheme of an alkali metal (or alkaline earth metal) compound and oxygen (or air) even without using a transition metal catalyst.

[0007] Solutions to the problem

[0008] In order to solve the above problems, the present invention provides a method for preparing 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural by a chemical selective oxidation reaction, wherein the chemical selective oxidation reaction is carried out in the presence of a promoter using oxygen or air as an oxidant, and the promoter is an alkali metal or alkaline earth metal compound.

[0009] Beneficial Effects of the Invention

[0010] According to the present invention, high-purity 2,5-furandicarboxylic acid (FDCA) can be prepared from 5-hydroxymethylfurfural (HMF) by a more economical, efficient and environmentally friendly method. 2,5-furandicarboxylic acid is widely and advantageously used in various fields such as packaging industry, automobile, pharmaceutical field, fine chemical industry, etc.

[0011] Best Mode for Carrying Out the Invention

[0012] The present invention is explained in more detail below.

[0013] The present invention relates to a method for preparing 2,5-furandicarboxylic acid (FDCA) by oxidizing the alcohol functional group and the aldehyde functional group in the 5-hydroxymethylfurfural (HMF) molecule through a chemical selective oxidation reaction, as shown in the following reaction scheme 1:

[0014] [Reaction Scheme 1]

[0015]

[0016] In the method for preparing 2,5-furandicarboxylic acid of the present invention, the chemical selective oxidation reaction is carried out in the presence of a promoter, which is an alkali metal compound or an alkaline earth metal compound.

[0017] In one embodiment, the alkali metal may be lithium, sodium, potassium, rubidium, cesium, or a combination thereof, and the alkaline earth metal may be barium, magnesium, or a combination thereof.

[0018] In one embodiment, the alkali metal compound or alkaline earth metal compound used as a promoter may be represented by the following Formula 1:

[0019] [Formula 1]

[0020] MOR

[0021] In Formula 1 above, M is an alkali metal or an alkaline earth metal; and R is an alkyl group, an aryl group, an alkylaryl group, or an arylalkyl group.

[0022] More specifically, in the above formula 1, R may be (C 1 ~C 10 ) alkyl, (C 6 ~C 10 ) aryl, (C 1 ~C 10 )alkyl(C 6 ~C 10 ) aryl or (C 6 ~C 10 )Aryl (C 1 ~C 10 ) alkyl, and more specifically, R may be (C 1 ~C 6 ) alkyl, (C 6 ) aryl, (C 1 ~C 6 )alkyl(C 6 ) aryl or (C 6 )Aryl (C 1 ~C 6 )alkyl.

[0023] According to the present invention, 2,5-furandicarboxylic acid (FDCA) can be prepared from 5-hydroxymethylfurfural (HMF) with high purity and high yield even without using an expensive transition metal catalyst. Therefore, in a preferred embodiment of the method for preparing 2,5-furandicarboxylic acid of the present invention, no transition metal catalyst is used.

[0024] In the method for preparing 2,5-furandicarboxylic acid of the present invention, the chemoselective oxidation reaction can be carried out in various solvents.

[0025] The solvent may be water, an organic solvent or a combination thereof, and the organic solvent may be a non-polar organic solvent, a polar protic organic solvent, a polar aprotic organic solvent or a combination thereof.

[0026] In one embodiment, the solvent can be water, n-propanol, isopropanol, n-butanol, tert-butanol, tert-amyl alcohol, tetrahydrofuran, 1,4-dioxane, dichloromethane, 1,2-dichloroethane, chlorobenzene, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, benzene, toluene or a mixture of two or more thereof.

[0027] In one embodiment, the promoter as an alkali metal compound or an alkaline earth metal compound (e.g., alkoxide) may be used in an amount of 1 to 10 equivalents based on 5-hydroxymethylfurfural (HMF), and in order to obtain a more efficient yield, the promoter as an alkali metal compound or an alkaline earth metal compound (e.g., alkoxide) is preferably used in an amount of 3 to 4 equivalents based on 5-hydroxymethylfurfural (HMF).

[0028] In one embodiment, the chemoselective oxidation reaction may be performed at a temperature of 20°C to 100°C, more specifically, preferably at a temperature of 20°C to 60°C, more specifically, preferably at a temperature of 40°C to 60°C.

[0029] In one embodiment, the chemical selective oxidation reaction may be carried out under conditions of 1 to 10 atmospheres, more specifically, preferably under 3 to 5 atmospheres, more specifically, preferably under 1 to 2 atmospheres.

[0030] Since the alkali metal compound or alkaline earth metal compound used as a promoter and oxygen or air used as an oxidant in the method for preparing 2,5-furandicarboxylic acid of the present invention have high reactivity, 2,5-furandicarboxylic acid can be obtained in good yield even if the chemical selective oxidation reaction is carried out under relatively low temperature conditions (e.g., about 40° C.) and relatively low pressure conditions (e.g., 2 atmospheres). Therefore, it can be said that the method for preparing 2,5-furandicarboxylic acid of the present invention is very useful in industrial large-scale production.

[0031] The present invention is explained in more detail by the following Examples and Comparative Examples. However, the scope of the present invention is not limited in any way. Example

[0032] In the following Examples 1 to 4, the solvent used is tert-butyl alcohol, the promoters used are sodium tert-butylate, sodium tert-valerate, sodium ethoxide and sodium methoxide, respectively, and the reaction is carried out at a reaction temperature of about 30° C. under atmospheric oxygen conditions for about 1 day.

[0033] In the following Examples 5 to 8, the solvent used was tert-butanol, the promoters used were lithium tert-butoxide, potassium tert-butoxide, magnesium tert-butoxide and barium tert-butoxide, respectively, and the reaction was carried out at a reaction temperature of about 30° C. under atmospheric oxygen conditions for about 1 day.

[0034] In the following Examples 9 to 23, the solvents used were tetrahydrofuran, 1,4-dioxane, dichloromethane, 1,2-dichloroethane, chlorobenzene, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, benzene, toluene, n-butanol, tert-amyl alcohol, N,N-dimethylacetamide, isopropanol and n-propanol, respectively, the promoter used was sodium tert-butoxide, and the reaction was carried out at a reaction temperature of about 25° C. under atmospheric oxygen conditions for about 1 day.

[0035] In the following Examples 24 to 27, the solvents used were n-butanol and t-butanol, the promoter used was sodium t-butoxide, and the reactions were carried out at reaction temperatures of 45°C and 55°C, respectively, under atmospheric oxygen conditions for about 1 day.

[0036] Example 1

[0037] At 30°C, 3 mL of tert-butyl alcohol was added to sodium tert-butylate (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystal to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 98%.

[0038] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0039] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0040] Example 2

[0041] At 30°C, 3 mL of tert-butyl alcohol was added to sodium tert-valerate (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 89%.

[0042] 1 H NMR (500 MHz, DMSO-d 6):δ13.62(br,2H),7.29(s,2H)

[0043] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0044] Example 3

[0045] At 30°C, 3 mL of tert-butyl alcohol was added to sodium ethoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 75%.

[0046] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0047] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0048] Example 4

[0049] At 30°C, 3 mL of tert-butyl alcohol was added to sodium methoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 56%.

[0050] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0051] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0052] Example 5

[0053] At 30°C, 3 mL of tert-butyl alcohol was added to lithium tert-butylate (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 88%.

[0054] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0055] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0056] Example 6

[0057] At 30°C, 3 mL of tert-butanol was added to potassium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 92%.

[0058] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0059] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0060] Example 7

[0061] At 30°C, 3 mL of tert-butyl alcohol was added to magnesium tert-butylate (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 75%.

[0062] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0063] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0064] Example 8

[0065] At 30°C, 3 mL of tert-butyl alcohol was added to barium tert-butylate (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 73%.

[0066] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0067] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0068] Example 9

[0069] At 25°C, 3 mL of tetrahydrofuran was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 81%.

[0070] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0071] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0072] Example 10

[0073] At 25°C, 3 mL of 1,4-dioxane was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 77%.

[0074] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0075] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0076] Embodiment 11

[0077] At 25°C, 3 mL of dichloromethane was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 82%.

[0078] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0079] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0080] Example 12

[0081] At 25 ° C, 3 mL of 1,2-dichloroethane was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 80%.

[0082] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0083] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0084] Embodiment 13

[0085] At 25°C, 3 mL of chlorobenzene was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 78%.

[0086] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0087] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0088] Embodiment 14

[0089] At 25°C, 3 mL of acetonitrile was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 75%.

[0090] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0091] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0092] Embodiment 15

[0093] At 25°C, 3 mL of dimethyl sulfoxide was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 83%.

[0094] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0095] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0096] Example 16

[0097] At 25°C, 3 mL of N,N-dimethylformamide was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 86%.

[0098] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0099] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0100] Embodiment 17

[0101] At 25°C, 3 mL of benzene was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 59%.

[0102] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0103] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0104] Embodiment 18

[0105] At 25°C, 3 mL of toluene was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 71%.

[0106] 1 H NMR (500MHz, DMSO-d6): δ13.62(br,2H), 7.29(s,2H)

[0107] 13 C NMR (125MHz, DMSO-d6): δ158.91, 147.04, 118.40

[0108] Embodiment 19

[0109] At 25°C, 3 mL of n-butanol was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 85%.

[0110] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0111] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0112] Embodiment 20

[0113] At 25 ° C, 3 mL of tert-amyl alcohol was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 80%.

[0114] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0115] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0116] Embodiment 21

[0117] At 25°C, 3 mL of N,N-dimethylacetamide was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 77%.

[0118] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0119] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0120] Embodiment 22

[0121] At 25°C, 3 mL of isopropanol was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 65%.

[0122] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0123] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0124] Embodiment 23

[0125] At 25 ° C, 3 mL of n-propanol was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 68%.

[0126] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0127] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0128] Embodiment 24

[0129] At 45 ° C, 3 mL of n-butanol was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 87%.

[0130] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0131] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0132] Embodiment 25

[0133] At 45 ° C, 3 mL of tert-butyl alcohol was added to sodium tert-butylate (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 82%.

[0134] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0135] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0136] Embodiment 26

[0137] At 55°C, 3 mL of n-butanol was added to sodium tert-butoxide (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 78%.

[0138] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0139] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0140] Embodiment 27

[0141] At 55°C, 3 mL of tert-butyl alcohol was added to sodium tert-butylate (3 equivalents), and then stirred for 5 minutes. 5-Hydroxymethylfurfural (HMF, 0.5 mmol) was added thereto, and the atmosphere was changed to oxygen, and then the mixture was stirred at room temperature for 1 day. A small amount of distilled water was added to the resulting mixture to terminate the reaction, and the acidity (pH) of the mixture was reduced to 1 with 1N HCl solution, and then the mixture was concentrated. The residue was purified by seed crystals to obtain 2,5-furandicarboxylic acid (FDCA) with a yield of 73%.

[0142] 1 H NMR (500 MHz, DMSO-d 6 ):δ13.62(br,2H),7.29(s,2H)

[0143] 13 C NMR (125 MHz, DMSO-d 6 ):δ158.91,147.04,118.40

[0144] The reaction conditions and results of Examples 1 to 27 are summarized in Tables 1 to 3 below.

[0145] [Table 1]

[0146]

[0147]

[0148] [Table 2]

[0149]

[0150] [Table 3]

[0151]

[0152] As can be seen from the above, according to the present invention, high-purity 2,5-furandicarboxylic acid (FDCA) can be prepared more efficiently and economically through a chemical selective oxidation reaction based on an environmentally friendly scheme of an alkali metal (or alkaline earth metal) compound promoter and oxygen (or air) oxidant.

Claims

1. A method for preparing 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural by chemical selective oxidation reaction, wherein a solvent comprising tert-butyl alcohol and a promoter are mixed at a temperature of 30° C., and then 5-hydroxymethylfurfural is added to the mixture comprising the solvent and the promoter, and then the mixture comprising the solvent, the promoter and 5-hydroxymethylfurfural is subjected to a chemical selective oxidation reaction in the presence of oxygen or air as an oxidant, and wherein the promoter is an alkali metal compound represented by the following Formula 1: [Formula 1] MOR wherein M is sodium or potassium; and R is tert-butyl.

2. The process for preparing 2,5-furandicarboxylic acid according to claim 1, wherein no transition metal catalyst is used.

3. The method for preparing 2,5-furandicarboxylic acid according to claim 1, wherein the chemical selective oxidation reaction is carried out at a temperature of 20°C to 100°C.

4. The method for preparing 2,5-furandicarboxylic acid according to claim 1, wherein the chemical selective oxidation reaction is carried out at 1 to 10 atmospheres.

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