SYNTHESIS OF DIKETONE COMPOUNDS FROM CARBOHYDRATES

Abstract

Providing a catalytic process for preparing 1,4-diketone compounds from furanic compounds and their precursors in a liquid medium, using an acid catalytic system and optionally in the presence of hydrogen and a hydrogenation catalyst, wherein the acidic catalytic system comprises a solid acid catalyst or a mixture of water and CO.sub.2.

Claims

1. A process for preparing 1,4-diketone compounds from a furanic compound of structure (I) or the precursor thereof [Compound (F)] in a liquid medium, ##STR00013## wherein: in structure (I), n is an integer between 0 and 4, and each R, being same or different, is independently selected from a group consisting of: hydrogen, OH, CHO, halogen, alkyl, alkenyl, alkynyl, OR.sup.o, SR.sup.o, NHR.sup.o, NR.sup.o.sub.2, COR.sup.o, COOR.sup.o, NH.sub.2, NO.sub.2, COOH, CN, hydroxyalkyl, alkylcarbonyloxy, alkoxycarbonyl, alkylcarbonyl and alkylsulfonylamino, with R.sup.o representing an optionally substituted alkyl, alkenyl, alkynyl, aryl, cycloalkyl, heteroaryl, or heterocycloalkyl; and wherein the process uses at least one acidic catalytic system selected from the group consisting of: (a) a solid acid catalyst, and (b) a mixture of water and CO.sub.2.

2. The process of claim 1, wherein the Compound (F) is selected from the compounds of structure (II): ##STR00014## wherein R.sup.1 and R.sup.2 are independently selected from a group consisting of: hydrogen, OH, CHO, halogen, alkyl, alkenyl, alkynyl, OR.sup.o, SR.sup.o, NHR.sup.o, NR.sup.o.sub.2, COR.sup.o, COOR.sup.o, NH.sub.2, NO.sub.2, COOH, CN, hydroxyalkyl, alkylcarbonyloxy, alkoxycarbonyl, alkylcarbonyl and alkylsulfonylamino.

3. The process of claim 1, wherein the Compound (F) is selected from the group consisting of: 5-hydroxymethylfurfural (HMF), 2-methyl-5-hydroxymethylfuran (MHMF), 2,5-dimethylfuran (DMF), 2,5-dihydroxymethylfuran (DHMF), and furfuryl alcohol (FA).

4. The process of claim 1, wherein the precursor of Compound (F) is selected from fructose and inulin.

5. The process of claim 1, wherein the 1,4-diketone compounds are those following the structure (III) below: ##STR00015## wherein R.sup.3 and R.sup.4 are independently selected from a group consisting of hydrogen, OH, CHO, halogen, alkyl, alkenyl, alkynyl, OR.sup.o, SR.sup.o, NHR.sup.o, NR.sup.o.sub.2, COR.sup.o, COOR.sup.o, NH.sub.2, NO.sub.2, COOH, CN, hydroxyalkyl, alkylcarbonyloxy, alkoxycarbonyl, alkylcarbonyl and alkylsulfonylamino.

6. The process of claim 5, wherein the 1,4-diketone compounds are selected from 1-hydroxymethylhexane-2,5-dione (HMHD), levulinic acid (LA), and 2,5-hexanedione (HDX).

7. The process of claim 1, wherein the process comprises reacting the Compound (F) in the presence of hydrogen and at least one hydrogenation catalyst [Catalyst (H)], wherein the Catalyst (H) comprises at least one metal [Metal (M)] selected from the group consisting of Pd, Ru, Pt, Rh, Ir, Fe, Co, Ni, Cu, Ag, Re, Os, and Au.

8. The process of claim 7, wherein the Catalyst (H) is a supported catalyst, which further comprises a support material on which the Metal (M) is deposited, wherein the support material is selected from a group consisting of activated carbon, silicon carbide, aluminum oxide, silicon dioxide, titanium dioxide, zirconium dioxide, magnesium oxide, zinc oxide and mixtures thereof.

9. The process of claim 7, wherein the Catalyst (H) is selected from the group consisting of Pd/C, Pearlman's catalyst, Adam's catalyst, Pt/C, and Raney-Ni.

10. The process of claim 1, wherein the acidic catalytic system comprises a solid acid catalyst.

11. The process of claim 10, wherein the solid acid catalyst is selected from a group consisting of acid ion exchange resins, zeolites, sulfated zirconia, zirconia, sulfated titania, tungsted zirconia, boron phosphate, and acidic clays.

12. The process of claim 10, wherein the solid acid catalyst is an acid ion exchange resin selected from a group consisting of sulphonated polystyrene or poly(styrene-divinylbenzene) copolymer and sulphonated phenol-formaldehyde resins.

13. The process of claim 10, wherein the solid acid catalyst is a ZSM-5 zeolite catalyst.

14. The process of claim 10, wherein the process is carried out in the presence of hydrogen and a Catalyst (H).

15. The process of claim 1, wherein the acidic catalytic system comprises a mixture of water and CO.sub.2.

16. The process of claim 15, wherein the liquid medium uses water as the sole liquid component.

17. The process of claim 15, wherein the liquid medium comprises a mixture of water and a non-aqueous liquid.

18. The process of claim 15, wherein the process is carried out in the presence of hydrogen and a Catalyst (H).

19. The process of claim 15, wherein the process is carried out in the absence of hydrogen and a Catalyst (H).

20. The process of claim 15, wherein the Compound (F) is selected from the group consisting of HMF, DMF, FA, MHMF, DHMF, fructose, and inulin.

Description

DESCRIPTION OF EMBODIMENTS

[0076] The following examples are provided to illustrate preferred embodiments of the invention and are not intended to restrict the scope thereof.

EXAMPLES

Example 1 Preparation of HMHD from HMF Using a Solid Acid Catalyst in the Presence of Hydrogen and a Catalyst (H)

[0077] To a 5 mL THF/H.sub.2O (9:1) mixture containing 9.75 mg of Pd/C and 16.5 mg of Amberlyst 15 (hereinafter abbreviated as A15), HMF (150 mg) was added. The thus obtained mixture was then placed inside a 45 ml autoclave and flushed with hydrogen. Subsequently, the autoclave was heated to 80 C. under a hydrogen pressure of 50 bar, for 15 hours. The reaction mixture was then let cool to room temperature, after which the reactor was vented and opened. A syringe filter was used to remove the solid catalysts from the reaction mixture, and the remaining liquid was analysed by GC using biphenyl as the internal standard. The HMF conversion was measured to be 100%, and the yield of HMHD was 77%.

[0078] The major co-product was LA, another 1,4-diketon compound, with 10% yield. Total carbon mass balance of this reaction reached 84%.

##STR00004##

Example 2 Preparation of HMHD from Fructose Using a Solid Acid Catalyst in the Presence of Hydrogen and a Catalyst (H)

[0079] To a 5 ml THF/H.sub.2O (9:1) mixture was added 250 mg Fructose, 16.25 mg Pd/C and 27.5 mg of A15 catalyst. The thus obtained mixture was then placed inside a 45 ml autoclave and flushed with hydrogen. Subsequently, the autoclave was heated to 80 C. under a hydrogen pressure of 20 bar, for 20 hours. The reaction mixture was then let cool to room temperature, after which the reactor was vented and opened. A syringe filter was used to remove the solid catalysts from the reaction mixture, and the remaining liquid was analysed by GC using biphenyl as the internal standard. The fructose conversation was measured to be 95%, and the yield of HMHD was 55%. The main co-products were LA and HMF, with 11% and 12% yield respectively. Total carbon mass balance of this reaction reached 82%.

##STR00005##

Example 3 Preparation of HDX from DMF Using CO.SUB.2./H.SUB.2.O Catalyst

[0080] A 5 ml water solution of DMF (150 mg, 1.56 mmol) was placed inside an autoclave and CO.sub.2 was introduced, to reach a pressure of 40 bar. Under this pressure, the reaction mixture was stirred and heated to 150 C., for 15 hours. The reaction mixture was then let cool to room temperature, after which the reactor was vented and opened to release CO.sub.2. The thus obtained aqueous mixture was analysed by GC using biphenyl as the internal standard. The DMF conversion was 100%, and the yield of HDX was as high as 95%.

##STR00006##

Example 4 Preparation of LA from FA Using CO.SUB.2./H.SUB.2.O Catalyst

[0081] A 5 mL water solution of FA (150 mg, 1.56 mmol) was placed inside an autoclave and CO.sub.2 was introduced, to reach a pressure of 40 bar. Under this pressure, the reaction mixture was stirred and heated to 150 C., for 15 hours. The reaction mixture was then let cool to room temperature, after which the reactor was vented and opened to release CO.sub.2. The thus obtained aqueous mixture was analysed by GC using biphenyl as the internal standard. The FA conversation was higher than 95%, and the yield of LA was 55%.

##STR00007##

Example 5 Preparation of HMHD from DHMF Using CO.SUB.2./H.SUB.2.O Catalyst in the Presence of Hydrogen and Catalyst (H)

[0082] To a mixture of deionized water (5 ml) and DHMF (150 mg, 1.17 mmol) was added Pd/C catalyst (3 mg, 1.4 mol). The resulting composition was then placed inside an autoclave and was flushed with hydrogen, until reaching a hydrogen pressure of 1 bar. Subsequently, CO.sub.2 was introduced up to a pressure of 39 bar (i.e. a total gas pressure of 40 bar). Under this gas pressure, the reaction mixture was stirred and heated to 120 C. for 10 hours. The reaction mixture was then let cool to room temperature, after which the reactor was vented and opened to release CO.sub.2 and hydrogen. A syringe filter was used to remove the solid Pd/C catalyst from the reaction mixture, and the remaining aqueous composition was analysed by GC using biphenyl as the internal standard. The DHMF conversion exceeded 95%, and the yield of HMHD was 60%.

##STR00008##

Example 6 Preparation of HMHD from HMF Using CO.SUB.2./H.SUB.2.O Catalyst in the Presence of Hydrogen and Catalyst (H)

[0083] To a mixture of deionized water (5 ml) and HMF (150 mg, 1.19 mmol) was added Pd/C catalyst (11 mg, 5.2 mol). The resulting composition was then placed inside an autoclave and was flushed with hydrogen, until reaching a hydrogen pressure of 10 bar. Subsequently, CO.sub.2 was introduced up to a pressure of 30 bar (i.e. a total gas pressure of 40 bar). Under this gas pressure, the reaction mixture was stirred and heated to 120 C. for 15 hours. The reaction mixture was then let cool to room temperature, after which the reactor was vented and opened to release CO.sub.2 and hydrogen. A syringe filter was used to remove the solid Pd/C catalyst from the reaction mixture, and the remaining aqueous composition was analysed by GC using biphenyl as the internal standard. The DHMF conversion was near 100%, and the yield of HMHD was 70%.

##STR00009##

Example 7 Preparation of HMHD from Inulin Using CO.SUB.2./H.SUB.2.O Catalyst

[0084] A 5 ml water solution of inulin (150 mg, 3 wt %) was placed inside an autoclave and CO.sub.2 was introduced, to reach a pressure of 40 bar. Under this pressure, the reaction mixture was stirred and heated to 150 C., for 15 hours. The reaction mixture was then let cool to room temperature, after which the autoclave reactor was vented and opened to release CO.sub.2. The thus obtained aqueous mixture was analysed by GC using biphenyl as the internal standard. The conversion of inulin was near 100%, and the overall yield of HMHD from inulin was about 15%.

##STR00010##

Example 8 Preparation of HMHD from Fructose Using CO.SUB.2./H.SUB.2.O Catalyst

[0085] A 5 ml water solution of fructose (150 mg, 3 wt %) was placed inside an autoclave and CO.sub.2 was introduced, to reach a pressure of 40 bar. Under this pressure, the reaction mixture was stirred and heated to 150 C., for 15 hours. The reaction mixture was then let cool to room temperature, after which the autoclave reactor was vented and opened to release CO.sub.2. The thus obtained aqueous mixture was analysed by GC using biphenyl as the internal standard. The conversion of fructose was near 100%, and the overall yield of HMHD from fructose was about 36%.

##STR00011##

Example 9 Preparation of HMHD from Inulin Using a Solid Acid Catalyst in the Presence of Hydrogen and a Catalyst (H)

[0086] To a 5 ml THF/H.sub.2O (9:1) mixture was added 250 mg Inulin, 16.25 mg Pd/C and 27.5 mg of A15 catalyst. The thus obtained mixture was then placed inside a 45 ml autoclave and flushed with hydrogen. Subsequently, the autoclave reactor was heated to 80 C. under a hydrogen pressure of 20 bar, for 20 hours. The reaction mixture was then let cool to room temperature, after which the reactor was vented and opened. A syringe filter was used to remove the solid catalysts from the reaction mixture, and the remaining liquid was analysed by GC using biphenyl as the internal standard. The inulin conversation reached 95%, and the yield of HMHD was 36%.

##STR00012##