Method for preparing phenylacetonitrile compounds and phenol compounds from lignin and model compounds thereof
By using poplar lignin or 2-phenoxy-1-phenylethanol to react with an acid catalyst, selectively break the bonds, and high-efficiency benzyl and phenol are prepared, solving the problem of using highly toxic raw materials and relying on petroleum resources in the prior art, and achieving an efficient and environmentally friendly preparation process.
Patent Information
- Application Number
- CN202510318924.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2025-05-09
AI Technical Summary
The prior art has problems in the use of highly toxic, flammable and explosive hydrogen cyanide and dependence on petroleum resources when preparing benzylene and phenol, resulting in high production costs and serious environmental pollution.
Poplar lignin or 2-phenoxy-1-phenylethanol is used as raw materials, and by regulating the acid catalyst, selectively breaking the carbon-oxygen bond and the carbon-carbon bond, phenol compounds are prepared.
The high conversion and high yields have been achieved. The conversion rate of lignin and its model compounds can reach more than 99%, and the total yield of benzylene compounds and phenol can reach more than 70% and more than 60%, respectively, and a preparation technical route that does not rely on fossil resources is provided.
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Figure CN119954614A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for preparing benzyl cyanide compounds and phenol compounds from lignin and a model compound thereof. Background Art
[0002] Benzyl cyanide compounds are an important class of organic compounds. Their structural characteristics are that the acetonitrile group is connected to the benzene ring. Benzyl cyanide is the simplest benzoyl cyanide compound. Benzyl cyanide compounds are derivatives formed by introducing different substituents on the benzene ring or acetonitrile group. Benzyl cyanide compounds are widely used in organic synthesis and industrial production, mainly as important raw materials for pharmaceutical intermediates, pesticide intermediates, dyes and fragrances.
[0003] The method for preparing benzyl cyanide at present has benzaldehyde and hydrogen cyanide reaction method, methyl chlorobenzene and sodium cyanide reaction method, styrene and hydrogen cyanide addition method, benzyl alcohol and hydrogen cyanide reaction method etc.At present, the most mature method for preparing benzyl cyanide in industry is benzaldehyde and hydrogen cyanide reaction method, i.e. benzaldehyde and hydrogen cyanide prepare benzyl cyanide under normal temperature or slightly heated condition.This method technology route is stable, and product benzyl cyanide purity is higher, and subsequent separation and purification is simple, but this method has obvious drawbacks such as severe toxicity, inflammable and explosive and storage difficulty of hydrogen cyanide.In order to overcome these problems, domestic and foreign scientific research workers are exploring the method for preparing benzyl cyanide compounds using safer raw materials.
[0004] Phenol compounds refer to organic compounds with one or more hydroxyl groups attached to a benzene ring, and the most common compound is phenol. Phenol compounds have important applications in industry, chemical synthesis and medicine, and are mainly used as raw materials or intermediates for synthetic resins, chemicals, medicines, dyes, pesticides, etc. Due to its strong reactivity and diverse chemical properties, phenol occupies an important position in the modern chemical industry.
[0005] At present, the most commonly used method for producing phenol in industry is catalytic reforming, which uses natural gas and petroleum as raw materials, and generates phenol under the action of a catalyst through the hydrogenation reaction of benzene. Although this method has the advantage of high yield, it needs to rely on petroleum and natural gas resources. With the fluctuation of global petroleum resources, the price of raw materials may fluctuate greatly, increasing production costs, and a variety of by-products will be produced during the catalytic reforming process. The separation and treatment of these by-products increase the complexity and cost of the production process. In order to overcome these problems, domestic and foreign researchers are exploring methods for preparing phenol compounds using cleaner raw materials. Summary of the invention
[0006] The object of the present invention is to provide a method for preparing benzyl cyanide compounds and phenol compounds from lignin and a model compound thereof. In the method, the raw materials are safe and readily available, and the benzyl cyanide compounds and phenol compounds are prepared by selectively breaking carbon-oxygen bonds and carbon-carbon bonds by regulating an acid catalyst.
[0007] To achieve the above purpose, the technical scheme adopted by the present invention is: a method for preparing benzyl cyanide compounds and phenol compounds from lignin and its model compounds, and the specific steps are: adding poplar lignin or 2-phenoxy-1-phenylethanol, an organic solvent, a nitrogen source, and an acid catalyst into a reaction container, stirring and refluxing at a certain temperature, after the reaction is completed, quenching and extracting the product, collecting the organic phase product, and obtaining the benzyl cyanide compounds and phenol compounds after distillation.
[0008] Preferably, the molar ratio of the 2-phenoxy-1-phenylethanol to the nitrogen source is 1:2.5; the mass ratio of the poplar lignin to the nitrogen source is 1:1; the concentration of 2-phenoxy-1-phenylethanol is 0.3 mol / L; and the concentration of lignin is 180 g / L.
[0009] Preferably, the acid catalyst is one of ion exchange resin A15, trifluoroacetic acid, Nafion beads, trifluoromethanesulfonic acid, methanesulfonic acid, p-toluenesulfonamide, sulfonic imidazolium ion liquid, and iron trifluoromethanesulfonate; when the acid catalyst is one of trifluoroacetic acid, trifluoromethanesulfonic acid, methanesulfonic acid, p-toluenesulfonamide, sulfonic imidazolium ion liquid, and iron trifluoromethanesulfonate, the molar ratio of 2-phenoxy-1-phenylethanol to the acid catalyst is 1:(0.3-0.7), and the mass ratio of poplar lignin to the acid catalyst is 1:0.5; when the acid catalyst is ion exchange resin A15 or Nafion beads, the amount of the acid catalyst is 30% of the mass of poplar lignin or 2-phenoxy-1-phenylethanol.
[0010] Preferably, the nitrogen source is one of formamide, hydroxylamine, trimethylsilyl azide, sodium nitrite and dichloramine.
[0011] Preferably, the organic solvent is one of dichloroethane, toluene, n-hexane, 1,4-dioxane, N,N-dimethylformamide, and anhydrous acetonitrile.
[0012] Preferably, the reaction temperature is 80-140° C., the reaction time is 8-24 h, and the reaction container is a high temperature and high pressure resistant screw-cap glass tube.
[0013] Preferably, the quenching solution is a saturated sodium carbonate solution.
[0014] Compared with the prior art, the present invention has the following beneficial effects:
[0015] (1) In the present invention, poplar wood lignin or 2-phenoxy-1-phenylethanol, an organic solvent, a nitrogen source, and a catalyst are added to a reaction tube to form a homogeneous system, and only one depolymerization is required to generate benzyl cyanide compounds and phenol compounds, and the operation is simple;
[0016] (2) The nitrogen source used in the present invention is simple and easy to obtain, and can react with poplar lignin or 2-phenoxy-1-phenylethanol under acidic conditions to produce benzyl nitrile compounds and phenol compounds that can be widely used in industry;
[0017] (3) By using the method of the present invention, the conversion rate of lignin and its model compounds can reach more than 99%, the total yield of benzyl cyanide compounds can reach more than 70%, and the total yield of phenol can reach more than 60%;
[0018] (4) The raw material of the present invention, poplar wood lignin or 2-phenoxy-1-phenylethanol, is derived from biomass and has high safety, thereby providing a technical route for preparing benzyl cyanide compounds and phenol compounds without relying on fossil resources. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is the GC spectrum of Example 1 in which 2-phenoxy-1-phenylethanol and trimethylsilyl azide are used as raw materials and phenylacetonitrile and phenol are prepared by catalytic depolymerization.
[0020] Figure 2 This is the GC-MS spectrum of Example 1 in which 2-phenoxy-1-phenylethanol and trimethylsilyl azide are used as raw materials for preparing benzyl cyanide and phenol by catalytic depolymerization; (a) benzyl cyanide, (b) phenol.
[0021] Figure 3 Example 1: Using 2-phenoxy-1-phenylethanol and trimethylsilyl azide as raw materials, catalytic depolymerization is used to prepare benzyl cyanide and phenol. 1 H-NMR spectrum.
[0022] Figure 4 This is the GC spectrum of Example 2 in which 2-phenoxy-1-phenylethanol and trimethylsilyl azide are used as raw materials and catalytic depolymerization is used to prepare benzyl cyanide and phenol.
[0023] Figure 5 This is the GC spectrum of Example 3 in which 2-phenoxy-1-phenylethanol and trimethylsilyl azide are used as raw materials for catalytic depolymerization to prepare benzyl cyanide and phenol.
[0024] Figure 6 This is the GC spectrum of Example 4 in which 2-phenoxy-1-phenylethanol and trimethylsilyl azide were used as raw materials and catalytic depolymerization was used to prepare benzyl cyanide and phenol.
[0025] Figure 7This is the GC spectrum of Example 5 in which 2-phenoxy-1-phenylethanol and trimethylsilyl azide are used as raw materials and catalytic depolymerization is used to prepare benzyl cyanide and phenol.
[0026] Figure 8 This is the GC spectrum of Example 6 in which 2-phenoxy-1-phenylethanol and sodium nitrite were used as raw materials and catalytic depolymerization was used to prepare benzyl cyanide and phenol.
[0027] Fig. 9 This is the GC-MS spectrum of Example 11, in which poplar lignin and trimethylsilyl azide are used as raw materials for catalytic depolymerization to prepare benzyl cyanide compounds and phenol compounds; (a) benzyl cyanide compounds, (b) phenol compounds. DETAILED DESCRIPTION
[0028] The present invention is further described in detail below in conjunction with embodiments.
[0029] In the following examples, 2-phenoxy-1-phenylethanol was purchased from Maclean Company, and all reagents used can be purchased from commercial sources.
[0030] Example 1
[0031] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL dichloroethane, 1.5mmol trimethylsilyl azide and 0.24mmol trifluoromethanesulfonic acid were added into a 15mL sealed tube, stirred and refluxed at 140°C for 24h, the product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was separated by extraction, and the product was tested and analyzed by gas chromatography and gas chromatography-mass spectrometry. Figure 1 and Figure 2 As shown in FIG. 1 , the conversion rate of 2-phenoxy-1-phenylethanol exceeds 99%, the yield of benzyl cyanide is 75.94%, and the yield of phenol is 67.29%. The product is then separated from benzyl cyanide and phenol by distillation. This example uses 2-phenoxy-1-phenylethanol and trimethylsilyl azide as raw materials to catalyze the depolymerization of benzyl cyanide and phenol. 1 H-NMR spectrum Figure 3 The structural characterization data are as follows:
[0032] 1HNMR (600MHz, CDCl3) δ7.42 (t, J=7.4Hz, 2H), 7.36 (dd, J=15.0, 7.3Hz, 3H), 7. 23(t,J=7.8Hz,2H),6.92(t,J=7.3Hz,1H),6.86(d,J=8.0Hz,2H),3.77(s,2H).
[0033] Example 2
[0034] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL dichloroethane, 1.5mmol trimethylsilyl azide and 30wt% ion exchange resin A15 were added into a 15mL sealed tube, stirred and refluxed at 100°C for 20h, the product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was separated by extraction, and the product was tested. After gas chromatography analysis, as shown in FIG. Figure 4 As shown, the conversion rate of 2-phenoxy-1-phenylethanol is over 99%, the yield of benzyl cyanide is 62.34%, and the yield of phenol is 54.82%. The product is then separated from benzyl cyanide and phenol by distillation.
[0035] Example 3
[0036] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL dichloroethane, 1.5mmol trimethylsilyl azide and 30wt% Nafion beads were added into a 15mL sealed tube, stirred and refluxed at 120°C for 16h, the product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was separated by extraction, and the product was tested. After gas chromatography analysis, as shown in Figure 5 As shown, the conversion rate of 2-phenoxy-1-phenylethanol is over 99%, the yield of benzyl cyanide is 64.48%, and the yield of phenol is 57.43%. The product is then separated by distillation to separate benzyl cyanide and phenol.
[0037] Example 4
[0038] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL dichloroethane, 1.5mmol trimethylsilyl azide and 0.3mmol trifluoroacetic acid were added into a 15mL sealed tube, stirred and refluxed at 140°C for 12h, the product obtained by the reaction was quenched with saturated sodium carbonate solution, and then the organic phase was separated by extraction, and the product was tested. After gas chromatography analysis, as shown in Figure 6 As shown, the conversion rate of 2-phenoxy-1-phenylethanol is over 99%, the yield of benzyl cyanide is 63.89%, and the yield of phenol is 49.73%. The product is then separated from benzyl cyanide and phenol by distillation.
[0039] Example 5
[0040] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL dichloroethane, 1.5mmol trimethylsilyl azide and 0.36mmol methanesulfonic acid were added into a 15mL sealed tube, stirred and refluxed at 80°C for 12h, the product obtained by the reaction was quenched with saturated sodium carbonate solution, and then the organic phase was separated by extraction, and the product was tested. After gas chromatography analysis, as shown in Figure 7As shown, the conversion rate of 2-phenoxy-1-phenylethanol is over 99%, the yield of benzyl cyanide is 71.84%, and the yield of phenol is 65.00%. The product is then separated from benzyl cyanide and phenol by distillation.
[0041] Example 6
[0042] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL anhydrous acetonitrile, 1.5mmol sodium nitrite and 0.42mmol p-toluenesulfonamide were added into a 15mL sealed tube, stirred and refluxed at 80°C for 12h, the product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was separated by extraction, and the product was tested. After gas chromatography analysis, as shown in Figure 8 As shown, the conversion rate of 2-phenoxy-1-phenylethanol is over 99%, the yield of benzyl cyanide is 60.29%, and the yield of phenol is 54.04%. The product is then separated from benzyl cyanide and phenol by distillation.
[0043] Example 7
[0044] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL N,N-dimethylformamide, 1.5mmol formamide and 0.18mmol sulfonic acid imidazolium ionic liquid were added to a 15mL sealed tube, stirred and refluxed at 80°C for 12h, the product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was extracted and separated, and the product was tested. After gas chromatography analysis, the conversion rate of 2-phenoxy-1-phenylethanol exceeded 99%, the yield of benzyl nitrile was 72.13%, and the yield of phenol was 62.20%. Then the product was separated from benzyl nitrile and phenol by distillation.
[0045] Example 8
[0046] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL 1,4-dioxane, 1.5mmol hydroxylamine and 0.18mmol iron trifluoromethanesulfonate were added to a 15mL sealed tube, and the mixture was stirred and refluxed at 80°C for 12h. The product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was extracted and separated. The product was tested. After gas chromatography analysis, the conversion rate of 2-phenoxy-1-phenylethanol exceeded 99%, the yield of benzyl nitrile was 67.69%, and the yield of phenol was 56.86%. The product was then separated from benzyl nitrile and phenol by distillation.
[0047] Example 9
[0048] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL n-hexane, 1.5mmol sodium nitrite and 0.24mmol trifluoromethanesulfonic acid were added to a 15mL sealed tube, and the mixture was stirred and refluxed at 140°C for 24h. The product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was extracted and separated. The product was tested. After gas chromatography analysis, the conversion rate of 2-phenoxy-1-phenylethanol exceeded 99%, the yield of benzyl nitrile was 64.65%, and the yield of phenol was 59.07%. The product was then separated from benzyl nitrile and phenol by distillation.
[0049] Example 10
[0050] 0.6mmol 2-phenoxy-1-phenylethanol, 2mL toluene, 1.5mmol dichloroamine and 0.24mmol trifluoromethanesulfonic acid were added to a 15mL sealed tube, and the mixture was stirred and refluxed at 140°C for 8h. The product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was extracted and separated. The product was tested. After gas chromatography analysis, the conversion rate of 2-phenoxy-1-phenylethanol exceeded 99%, the yield of benzyl nitrile was 70.99%, and the yield of phenol was 68.94%. The product was then separated from benzyl nitrile and phenol by distillation.
[0051] Embodiment 11
[0052] 180 mg of poplar lignin, 1 mL of dichloroethane, (1.5 mmol, 172.8 mg) of trimethylsilyl azide and (0.6 mmol, 90 mg) of trifluoromethanesulfonic acid were added into a 15 mL sealed tube, stirred and refluxed at 140 °C for 24 h, the product obtained by the reaction was quenched with a saturated sodium carbonate solution, and then the organic phase was separated by extraction, and the product was tested. After gas chromatography and mass spectrometry analysis, as shown in FIG. Fig. 9 As shown, the yield of benzyl cyanide compounds is 36.98%, and the yield of phenol compounds is 32.58%. The product is then distilled to separate the benzyl cyanide compounds and the phenol compounds.
Claims
1. A method for preparing benzyl cyanide compounds and phenol compounds from lignin and its model compound, characterized in that: The specific steps are: adding poplar lignin or 2-phenoxy-1-phenylethanol, an organic solvent, a nitrogen source, and an acid catalyst into a reaction container, stirring and refluxing the reaction at a certain temperature, quenching and extracting the product after the reaction is completed, collecting the organic phase product, and obtaining benzyl cyanide compounds and phenol compounds after distillation.
2. The method for preparing benzyl cyanide compounds and phenol compounds from lignin and its model compound according to claim 1, characterized in that: The molar ratio of the 2-phenoxy-1-phenylethanol to the nitrogen source is 1:2.5; the mass ratio of the poplar lignin to the nitrogen source is 1:1; the concentration of 2-phenoxy-1-phenylethanol is 0.3 mol / L; and the concentration of lignin is 180 g / L.
3. A method for preparing benzyl cyanide compounds and phenol compounds from lignin and its model compound according to claim 1 or 2, characterized in that: The acid catalyst is one of ion exchange resin A15, trifluoroacetic acid, Nafion beads, trifluoromethanesulfonic acid, methanesulfonic acid, p-toluenesulfonamide, sulfonic acid imidazolium ion liquid, and iron trifluoromethanesulfonate; when the acid catalyst is one of trifluoroacetic acid, trifluoromethanesulfonic acid, methanesulfonic acid, p-toluenesulfonamide, sulfonic acid imidazolium ion liquid, and iron trifluoromethanesulfonate, the molar ratio of 2-phenoxy-1-phenylethanol to the acid catalyst is 1:(0.3-0.7), and the mass ratio of poplar lignin to the acid catalyst is 1:0.5; when the acid catalyst is ion exchange resin A15 or Nafion beads, the amount of the acid catalyst is 30% of the mass of poplar lignin or 2-phenoxy-1-phenylethanol.
4. A method for preparing benzyl cyanide compounds and phenol compounds from lignin and its model compound according to claim 1 or 2, characterized in that: The nitrogen source is one of formamide, hydroxylamine, trimethylsilyl azide, sodium nitrite and dichloramine.
5. A method for preparing benzyl cyanide compounds and phenol compounds from lignin and its model compound according to claim 1 or 2, characterized in that: The organic solvent is one of dichloroethane, toluene, n-hexane, 1,4-dioxane, N,N-dimethylformamide and anhydrous acetonitrile.
6. A method for preparing benzyl cyanide compounds and phenol compounds from lignin and its model compound according to claim 1 or 2, characterized in that: The reaction temperature is 80-140° C., the reaction time is 8-24 hours, and the reaction container is a high temperature and high pressure resistant screw-cap glass tube.
7. A method for preparing benzyl cyanide compounds and phenol compounds from lignin and its model compound according to claim 1 or 2, characterized in that: The quenching solution is a saturated sodium carbonate solution.