Method for preparing tricarboxylate from renewable alpha-angelica lactone and itaconate

Abstract

The invention discloses a method for preparing tricarboxylic acid ester from renewable alpha-angelica lactone and itaconate. The method comprises the following specific steps: in an organic solvent system, performing condensation reaction on alpha-angelica lactone and itaconate under the action of a basic catalyst; and carrying out ring-opening / hydrodeoxygenation one-pot reaction on the condensation product under the catalysis of a metal / acid catalyst to prepare the tricarboxylate. The invention provides a method for preparing tricarboxylate from renewable biomass alpha-angelica lactone and itaconate, the whole preparation process is simple and convenient to operate, green and environment-friendly, and the method has application prospects in the fields of bio-based polymer new materials, biomass-based plasticizers and the like.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis of compounds, and in particular to a method for preparing tricarboxylic acid esters from renewable alpha-angelica lactone and itaconate. Background Art

[0002] Tricarboxylic acids (such as citric acid, C22-tricarboxylic acid, cyanuric acid, 1,2,3-propanetricarboxylic acid, etc.) are a very important class of industrial monomers. They can be used as functional monomers or cross-linking agents, copolymerized or reacted with other raw materials to synthesize various high-performance biodegradable plastics, such as polylactic acid (PLA), polycaprolactone (PCL), etc. In industry, these tricarboxylic acids are made from petroleum as raw materials through a series of reactions. This method is highly dependent on non-renewable petroleum resources and will produce a large amount of carbon emissions. The development of a renewable biomass supply system to produce tricarboxylic acids has always attracted the attention of the scientific and industrial communities.

[0003] Itaconic acid esters are fermented from biomass resources and have been industrially mass-produced and used for modified products or plastic products. At present, the annual output of itaconic acid has exceeded 100,000 tons. Its stable biomass source and mature mass production technology provide an important premise for the wider application of itaconic acid. Itaconic acid has a double bond and two carboxyl groups in its molecular structure, which gives itaconic acid excellent chemical activity. Itaconic acid has a variety of derivatives and can be used to prepare a variety of bio-based polymers through molecular design. The double bond can be used for addition and polymerization, and the carboxyl group can be used to prepare polyester materials or polyamide materials through condensation polymerization with other diols or diamine monomers. At present, there are no reports on the preparation of polycarboxylic acids through a series of reactions starting from itaconic acid esters. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing tricarboxylic acid esters from renewable alpha-angelica lactone and itaconate, which has simple steps and high yield and can prepare green high-yield tricarboxylic acid esters.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: a method for preparing tricarboxylic acid esters from renewable α-angelica lactone and itaconate, comprising the following steps:

[0006] In the first step, in an organic solvent system, the α-angelica lactone shown in Formula 1 undergoes a condensation reaction with the itaconate shown in Formula 2 under the action of a basic catalyst, and the reaction is carried out at 0-100° C. for 12-16 hours to generate an addition product shown in Formula 3;

[0007]

[0008] In the second step, the addition product shown in Formula 3 is dissolved in an alcohol organic solvent shown in Formula 4, and a ring-opening / hydrodeoxygenation reaction occurs under the catalysis of a metal catalyst and an acid catalyst to prepare a tricarboxylic acid ester shown in Formula 5; the reaction temperature is between 200-300° C., the reaction time is between 12-16 hours, and the hydrogen pressure is between 1-6 MPa;

[0009]

[0010] In the formula, R is selected from one of C1-C10 alkyl, phenyl, and benzyl. 1 is selected from one of C1-C10 alkyl, phenyl, and benzyl, R 2 It is selected from one of C1-C10 alkyl groups.

[0011] Preferably, in the first step, the alkaline catalyst is selected from one or more of the following catalysts, homogeneous catalysts: 4-dimethylaminopyridine (DMAP), triethylamine (Et3N), 1,5,7-triazabicyclo[4.4.0]decene-5-ene (TBD), 1,8-diazabispiro[5.4.0]undec-7-ene (DBU), 1,4-diazabicyclo[2.2.2]octane (DABCO), sodium methoxide (NaOCH3), sodium ethoxide (NaOEt), sodium tert-butoxide (NaO t Bu), sodium n-butoxide (NaO n Bu), diethylamine (Et2NH), aniline (C6H5NH2), diethylmethylamine (Et2NMe), diisopropylamine ( i Pr2NH), diisopropylethylamine ( i Pr2NEt), hexamethylenetetramine (HMTA), piperidine (Pip); heterogeneous catalysts: KF / Al2O3, Mg-Al hydrotalcite, Cs2O / Al2O3, IRA-402, sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), cesium hydroxide (CsOH), calcium oxide (CaO), magnesium oxide (MgO), zinc oxide (ZnO), aluminum oxide (Al2O3), cerium oxide (CeO2), titanium oxide (TiO2), potassium ethoxide (KOEt), potassium tert-butoxide (KO t Bu), potassium n-butoxide (KO n Bu), lithium methoxide (LiOCH3), lithium ethoxide (LiOEt), lithium tert-butoxide (LiO t Bu), lithium n-butoxide (LiO n Bu);

[0012] Among them, for the homogeneous catalyst, its usage is calculated by molar ratio, and the molar ratio of the homogeneous catalyst to α-angelica lactone is 0.01-20. For the heterogeneous catalyst, its usage is calculated by mass ratio, and the mass ratio of the heterogeneous catalyst to α-angelica lactone is 0.01-20.

[0013] Preferably, in the first step, the organic solvent is selected from one or more of dichloromethane (DCM), dichloroethane (DCE), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-THF), 1,4-dioxane (1,4-Dioxane), n-hexane (Hexane), cyclohexane (Cyclohexane), n-octane (Cyclooctane), ethyl acetate (EA), cyclohexanone (CYH), toluene (PhMe), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), acetone (ACE), ethanol (EtOH), isopropanol (IPA), N-methylpyrrolidone (NMP), propylene carbonate (PC), dimethyl carbonate (DMC), methanol (MeOH), and tert-butanol, and the substrate concentration range is 0.5-1 mol / L.

[0014] Preferably, in the first step, the reaction temperature is 10° C. and the reaction time is 15 h.

[0015] Preferably, the metal / acid catalyst in the second step can be a physical mixture of a metal catalyst and an acid catalyst, the metal catalyst is selected from one of RaneyNi, Raney Cu, Raney Co, Pt / C, Pd / C, Ru / C, Ir / C, Rh / C, Co / C, Ni / C, and Cu / C, and the acid catalyst is selected from one of phosphotungstic acid (HPW), silicotungstic acid (HSiW), H-Beta, HY, H-MOR, H-ZSM5, and MCM-41; the ratio of the amount of the metal catalyst to the mass of the addition product shown in Formula 3 is between 0.01 and 1, and the ratio of the amount of the acid catalyst to the mass of the addition product shown in Formula 3 is between 0.01 and 1;

[0016] The metal / acid catalyst can also be a supported catalyst, with one of H-Beta, HY, H-MOR, H-ZSM5, and MCM-41 as the carrier, the supported metal being one or more of Ni, Co, Cu, Pd, Pt, Ru, Rh, and Ir, and the metal mass loading being 0.01-60%; wherein the ratio of the amount of the metal / acid catalyst to the mass of the addition product shown in Formula 3 is between 0.01 and 1.

[0017] Preferably, in the second step, the alcohol organic solvent is selected from one of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol and nonanol, and the substrate concentration range is 0.01-1 mol / L.

[0018] Preferably, in the second step, the ring-opening / hydrodeoxygenation reaction temperature is 240° C., the reaction time is 15 h, and the hydrogen pressure is 2 MPa.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention can completely realize the preparation of tricarboxylic acid esters with high yield from biomass derivatives α-angelica lactone, dimethyl itaconate and other itaconate compounds through a two-step method, and is a bio-based carboxylic acid ester compound; this type of compound is both oil-soluble and water-soluble and easy to adjust. It has various excellent properties of traditional siloxanes, such as high and low temperature resistance, electrical insulation, low surface tension, etc., and at the same time has special properties such as lubrication, softening effect, good spreadability and emulsification stability provided by polyether, and is used in the fields of electronics and electrical, textiles, light industry, construction, cosmetics, medicine, and food.

[0021] 2. The entire route uses biomass as raw material. It is a new green route that does not produce harmful substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 .MS spectrum of product 3a obtained in Example 69.

[0023] Figure 2 .GC spectrum of product 3a obtained in Example 69.

[0024] Figure 3 Example 69 obtained product 3a 1 H NMR spectrum.

[0025] Figure 4 Example 69 obtained product 3a 13 C NMR spectrum.

[0026] Figure 5 .MS spectrum of the hydrogenation product 5a obtained in Example 111.

[0027] Figure 6 .GC spectrum of the hydrogenation product 5a obtained in Example 111.

[0028] Figure 7 Example 111 Hydrogenated product 5a 1 H NMR spectrum.

[0029] Figure 8Example 111 Hydrogenated product 5a 13 C NMR spectrum. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031]

[0032] Example 1-78

[0033] Biomass derivatives α-angelica lactone and itaconate undergo condensation reaction under alkaline conditions to generate product 1 (effects of catalyst, temperature, solvent, and time)

[0034] Add α-angelica lactone (1 mmol, 0.981 g) and itaconate (1.2 mmol, 0.1896 g) to a 4 mL sample bottle, stir in an ice-water bath for 5 min, then add 0.15 mmol of a homogeneous alkaline catalyst / 20 wt% of a heterogeneous alkaline catalyst, and react at 0-100 °C for 12-16 h.

[0035] Table 1. Effects of catalyst, temperature, solvent and time on the reaction

[0036]

[0037]

[0038]

[0039] From the results in Table 1, it can be seen that the reaction has a good performance in homogeneous catalysts TBD and DBU, and the reaction yield is high. Among them, DBU has the best catalytic performance, and the heterogeneous catalyst has poor catalytic performance. Considering the economic efficiency of the reaction, the recyclable heterogeneous catalyst is not selected to continue to increase the temperature to screen the optimal conditions; it can be seen from the above table that the temperature has a greater impact on the reaction. The lower the temperature, the more conducive to the formation of the product. When the temperature is 10°C, the yield is as high as 90%, and the yield does not change when the temperature is further reduced; by screening different solvents, it is found that dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), N-methylpyrrolidone (NMP) and propylene carbonate (PC) have relatively good effects on the reaction, but considering the difficulty of subsequent treatment of the solvent and from the perspective of environmental greenness, N, N-dimethylformamide (DMF) is selected as the solvent. By screening different reaction times, it is found that extending the time will increase the yield of the addition product. The yield of the addition product is 86% after 14h reaction, and the yield of 15h reaction can reach 90%, so 15h is selected as the reaction time of the reaction.

[0040] The MS spectrum of the product 3a obtained in Example 69 is as follows Figure 1 As shown in the figure, it can be seen that the maximum mass-to-charge ratio of the molecular ion peak of the substance is m / z=256, while the relative molecular mass of α-angelica lactone is 98, the relative molecular mass of ethyl acrylate is 158, and the relative molecular weight of product 3a is 256, so this product may be the target addition product.

[0041] The GC spectrum of the product 3a obtained in Example 69 is as follows Figure 2 As shown. The gas chromatograph set the injection port temperature to 270°C, the initial column box temperature to 40°C, the heating rate to 15°C / min, the temperature to 280°C and maintained for 5 min. The substance that appeared at 9.7 min in the GC graph was the internal standard n-tridecane, and the substance that appeared at 13.4 min was the addition product 3a.

[0042] Example 69: Product 3a 1 H NMR spectrum Figure 3 shown. 1 H NMR(600MHz,Chloroform-d)δ7.35(dd,J=5.6,1.3Hz,1H),6.04(dd,J=48.2,5.6Hz ,1H),3.88–3.50(m,6H),2.93–2.24(m,4H),2.13–1.73(m,1H),1.64–1.37(m,3H).

[0043] Example 69: Product 3a 13 C NMR spectrum Figure 4 shown. 13 C NMR(151MHz,Chloroform-d)δ174.46(d,J=8.9Hz),172.87–169.99(m),162.19–154.11(m),121.05(d,J=8 9.5Hz), 87.68 (d, J = 3.5Hz), 54.64–47.69 (m), 39.38 (d, J = 58.1Hz), 37.71–34.76 (m), 24.61 (d, J = 63.8Hz).

[0044] Examples 79-120

[0045]

[0046] The addition product 3a undergoes a ring-opening / hydrodeoxygenation reaction to generate a tricarboxylic acid ester under the catalysis of a metal catalyst / acidic catalyst; the metal catalyst is selected from RaneyNi, Raney Cu, Raney Co, Pt / C, Pd / C, Ru / C, Ir / C, Rh / C, Co / C, Ni / C, Cu / C, and Fe / C; the acidic catalyst is selected from phosphotungstic acid (HPW), silicotungstic acid (HSiW), H-Beta, HY, H-MOR, H-ZSM5, MCM-41, H-Beta, HY, H-MOR, H-ZSM5, and MCM-41; the metal / acid catalyst can also be a supported catalyst: one of H-Beta, HY, H-MOR, H-ZSM5, and MCM-41 is used as a carrier, and the supported metal is Ni, Co, Cu, Pd, Pt, Ru, Rh, or Ir.

[0047] In a 30 mL reactor, the addition product of itaconate ester 3a (0.256 g, 1 mmol) and 4.5 mL of methanol were added, and then 50 mg of metal catalyst (active metal loading 5 wt%) and 50 mg of acidic molecular sieve catalyst were added. The reaction was carried out at a certain temperature and 2 MPa hydrogen pressure for 15 h to obtain tricarboxylic acid ester.

[0048] Table 2. Effects of catalyst, time and temperature on hydrogenation reaction

[0049]

[0050]

[0051] From the results in Table 2, it can be seen that the hydrogenation capabilities of different metal catalysts are different, among which Pd / C has the best ability, and Pt / C, Ru / C, and Rh / C have similar hydrogenation capabilities. Considering their catalytic effects, Pd / C is selected as the hydrogenation catalyst, and the molecular sieve catalyst HPW has the best effect, so HPW is selected. Considering that the metal loading on the molecular sieve has little effect on the reaction, the hydrogenation catalyst and the molecular sieve catalyst are mixed for the experiment. Then the temperature when methanol is used as a solvent and also as a reactant for the hydrogenation reaction is screened. It can be concluded that the yield of the product increases with increasing temperature, but considering that the temperature continues to increase, the reaction pressure will increase sharply, and the reaction pressure will increase, which is not conducive to subsequent experiments, so 240℃ is selected as the conditional temperature of the reaction; the reaction time is screened for the reaction, and it is found that the yield of the reaction is the same for 14h, 15h, and 16h. In order to ensure the complete conversion of the raw materials, 15h is selected as the conditional time of the reaction, and finally the optimal conditions for the hydrogenation reaction are obtained.

[0052] In practical applications, the service life of the catalyst needs to be examined. Therefore, methanol was used as the solvent and HPW as the catalyst. The reaction was carried out at 240°C for 15 hours to study the recycling of Pd / C. After the first reaction, the reaction was cooled to room temperature, an internal standard (tridecane) was added, and the yield was calculated by GC. Table 3 shows that the yield did not decrease significantly after the fifth reaction (the fourth cycle), so the Pd / C catalyst can be recycled 3 times.

[0053] Table 3. Pd / C cycle experiment

[0054]

[0055] The MS spectrum of the hydrogenation product 5a obtained in Example 111 is as follows: Figure 5 As shown in the figure, it can be seen that the maximum mass-to-charge ratio of the molecular ion peak of the substance is m / z=274, while the relative molecular mass of product 1 is 256. After ring-opening hydrodeoxygenation, the relative molecular weight of hydrogenated product 5a is 274. Therefore, this product may be the target hydrogenated product 5a, and nuclear magnetic resonance is needed for auxiliary verification in the future.

[0056] The GC spectrum of the hydrogenation product 5a obtained in Example 111 is as follows: Figure 6 As shown. The gas chromatograph set the injection port temperature to 270°C, the initial column box temperature to 40°C, the heating rate to 15°C / min, the temperature to 280°C and maintained for 5 minutes. The substance that appeared at 9.7min in the GC graph was the internal standard n-tridecane, and the substance that appeared at 14.7min was the hydrogenation product 5a.

[0057] Example 111 Hydrogenated product 5a 1 H NMR spectrum Figure 7 shown. 1 H NMR(600MHz,Chloroform-d)δ3.80–3.51(m,9H),2.85(p,J=17.2,4.3,2.5Hz,1H), 2.52(dd,1H),2.38(p,3H),2.05(p,3H),1.93–1.76(m,2H),1.38(d,J=33.4Hz,3H).

[0058] Example 111 Hydrogenated product 5a 13 C NMR spectrum Figure 8 shown. 13 C NMR (151MHz, Chloroform-d) δ180.69–168.46(m), 57.74–48.18(m), 43.68–17.62(m).

[0059] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for preparing tricarboxylic acid esters from renewable α-angelica lactone and itaconate, characterized in that: The following steps are involved: In the first step, in an organic solvent system, the α-angelica lactone shown in Formula 1 undergoes a condensation reaction with the itaconate shown in Formula 2 under the action of a basic catalyst, and the reaction is carried out at 0-100° C. for 12-16 hours to generate an addition product shown in Formula 3; In the second step, the addition product shown in Formula 3 is dissolved in an alcohol organic solvent shown in Formula 4, and a ring-opening / hydrodeoxygenation reaction occurs under the catalysis of a metal / acid catalyst to prepare a tricarboxylic acid ester shown in Formula 5; the reaction temperature is between 200-300° C., the reaction time is between 12-16 hours, and the hydrogen pressure is between 1-6 MPa; In the formula, R is selected from one of C1-C10 alkyl, phenyl, and benzyl. 1 is selected from one of C1-C10 alkyl, phenyl, and benzyl, R 2 Selected from one of C1-C10 alkyl groups.

2. A method for preparing tricarboxylic acid esters from renewable α-angelica lactone and itaconate according to claim 1, characterized in that: In the first step, the alkaline catalyst is selected from one or more of the following catalysts: homogeneous catalyst: 4-dimethylaminopyridine, triethylamine, 1,5,7-triazabicyclo[4.4.0]decene-5-ene, 1,8-diazabispiro[5.4.0]undec-7-ene, 1,4-diazabicyclo[2.2.2]octane, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium n-butoxide, diethylamine, aniline, diethylmethylamine, diisopropylamine, diisopropylethylamine, hexamethylenetetramine, piperidine; heterogeneous catalyst: KF / Al2O3, Mg-Al hydrotalcite, Cs2O / Al2O3, sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, calcium oxide, magnesium oxide, zinc oxide, aluminum oxide, cerium oxide, titanium oxide, potassium ethoxide, potassium tert-butoxide, potassium n-butoxide, lithium methoxide, lithium ethoxide, lithium tert-butoxide, lithium n-butoxide; Among them, for the homogeneous catalyst, its usage is calculated by molar ratio, and the molar ratio of the homogeneous catalyst to α-angelica lactone is 0.01-20. For the heterogeneous catalyst, its usage is calculated by mass ratio, and the mass ratio of the heterogeneous catalyst to α-angelica lactone is 0.01-20.

3. The method for preparing tricarboxylic acid esters from renewable α-angelica lactone and itaconate according to claim 1, characterized in that: In the first step, the organic solvent is selected from one or more of dichloromethane, dichloroethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, n-hexane, cyclohexane, n-octane, ethyl acetate, cyclohexanone, toluene, dimethyl sulfoxide, N,N-dimethylformamide, acetone, ethanol, isopropanol, N-methylpyrrolidone, propylene carbonate, dimethyl carbonate, methanol, and tert-butanol, and the substrate concentration range is 0.5-1 mol / L.

4. The method for preparing tricarboxylic acid esters from renewable α-angelica lactone and itaconate according to claim 1, characterized in that: In the first step, the reaction temperature was 10°C and the reaction time was 15 h.

5. The method for preparing tricarboxylic acid esters from renewable α-angelica lactone and itaconate according to claim 1, characterized in that: The metal / acid catalyst in the second step can be a physical mixture of a metal catalyst and an acid catalyst, the metal catalyst is selected from one of RaneyNi, Raney Cu, Raney Co, Pt / C, Pd / C, Ru / C, Ir / C, Rh / C, Co / C, Ni / C, and Cu / C, and the acid catalyst is selected from one of phosphotungstic acid, silicotungstic acid, H-Beta, HY, H-MOR, H-ZSM5, and MCM-41; the ratio of the amount of the metal catalyst to the mass of the addition product shown in Formula 3 is between 0.01 and 1, and the ratio of the amount of the acid catalyst to the mass of the addition product shown in Formula 3 is between 0.01 and 1; The metal / acid catalyst can also be a supported catalyst, with one of H-Beta, HY, H-MOR, H-ZSM5, and MCM-41 as the carrier, the supported metal being one or more of Ni, Co, Cu, Pd, Pt, Ru, Rh, and Ir, and the metal mass loading being 0.01-60%; wherein the ratio of the amount of the metal / acid catalyst to the mass of the addition product shown in Formula 3 is between 0.01 and 1.

6. The method for preparing tricarboxylic acid esters from renewable α-angelica lactone and itaconate according to claim 1, characterized in that: In the second step, the alcohol organic solvent is selected from one of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol and nonanol, and the substrate concentration range is 0.01-1 mol / L.

7. The method for preparing tricarboxylic acid esters from renewable α-angelica lactone and itaconate according to claim 1, characterized in that: In the second step, the ring-opening / hydrodeoxygenation reaction temperature is 240° C., the reaction time is 15 h, and the hydrogen pressure is 2 MPa.

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