Green Synthesis of o-Chlorobenzaldehyde Catalyzed by Titanium Silica Molecular Sieve
Through a one-step oxidation reaction catalyzed by titanium silicon molecular sieve, the problems of many by-products and environmental pollution in the existing technology are solved, and high-efficiency and low-cost high-purity ortho-chlorobenzaldehyde preparation is achieved. The catalyst and solvent can be recycled, reducing the pollute.
Patent Information
- Application Number
- CN202211466937.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-22
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2042-11-22
AI Technical Summary
In the prior art, the synthesis method of orthochlorobenzaldehyde has many by-products, large catalyst usage, and a large amount of wastewater and waste acid generated by hydrolysis, resulting in problems of environmental pollution and high production costs, and poor product quality and low yield.
Titanium silicon molecular sieve is used as a catalyst to convert o-chlorobenzaldehyde into high-purity o-chlorobenzaldehyde through a one-step oxidation reaction. The only by-product is water. The catalyst and solvent can be recycled, reducing contamination. Waste emissions.
The high purity (99%) preparation of ortho-chlorobenzaldehyde was achieved, with a conversion rate and yield of 97%, reducing production costs, and the process was simple and convenient, and the recycling of catalysts and solvents reduced pollution.
Smart Images
Figure CN115819201B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of organic chemistry and relates to a method for synthesizing a fine chemical intermediate, in particular to a green synthesis process of o-chlorobenzaldehyde catalyzed by titanium silicon molecular sieve. Background Art
[0002] o-Chlorobenzaldehyde is a derivative of aromatic aldehydes. It is a colorless or light yellow oily liquid with a melting point of 11°C, a boiling point of 213-214°C, a relative density of 1.2483 (20-40°C), a refractive index of 1.5662, slightly soluble in water, soluble in ethanol, ether, acetone and benzene, with a strong aldehyde smell, low toxicity and irritation. o-Chlorobenzaldehyde is an important intermediate for the synthesis of fine chemicals such as medicines, dyes and pesticides. It is the main raw material for the manufacture of pharmaceuticals such as o-chlorobenzyl, o-chlorobenzyl chloride and clofenacic acid sodium. It is also a raw material for the manufacture of high-efficiency acaricide products in pesticides. Therefore, the market demand for o-chlorobenzaldehyde is relatively large.
[0003] So far, the synthesis methods of o-chlorobenzaldehyde reported in the literature include chlorination hydrolysis, direct oxidation and indirect oxidation, among which chlorination hydrolysis is the most commonly used method for industrial production. The classic chlorination hydrolysis process is to chlorinate o-chlorotoluene into o-chlorobenzyl dichloride, and then obtain o-chlorobenzaldehyde through catalytic hydrolysis. However, this method has more by-products in the chlorination process and poor yield, and in the o-chlorobenzyl dichloride hydrolysis process, concentrated acid or soluble metal salts need to be used as hydrolysis catalysts, and by-products are produced during chlorination due to different chlorination depths, not only with poor product quality, low yield, and a large amount of waste acid and wastewater, but also a large amount of metal ions in the wastewater, which seriously pollutes the environment and endangers people's health.
[0004] The direct oxidation method and the indirect oxidation method usually use urotropine, nitric acid or manganese dioxide / sulfuric acid as oxidants, which consume a large amount of oxidants and produce a large amount of wastewater and waste acid. The single-pass conversion rate and yield are low, which not only has high production costs but also pollutes the environment.
[0005] The above methods all have shortcomings, such as excessive use of catalysts, large amounts of wastewater and waste acid produced by hydrolysis, many by-products, low selectivity and yield of target products, and many other problems that need to be solved urgently. Summary of the invention
[0006] Technical problem to be solved: In order to overcome the deficiencies of the prior art, high-purity o-chlorobenzaldehyde is obtained, and the catalyst can be regenerated and recycled without polluting wastewater discharge; in addition, the synthesis route is shortened and the synthesis efficiency is improved by adopting a new catalyst; in view of this, the present invention provides a green synthesis process of o-chlorobenzaldehyde catalyzed by titanium silicon molecular sieve.
[0007] Technical solution: A green synthesis process of o-chlorobenzaldehyde catalyzed by titanium silicalite, wherein o-chlorobenzyl alcohol is used as a starting material and titanium silicalite is used as a catalyst to prepare high-purity o-chlorobenzaldehyde through a one-step oxidation reaction in an oxidant and a solvent.
[0008] The chemical structural formula of the o-chlorobenzaldehyde is:
[0009]
[0010] The reaction route is:
[0011]
[0012] Preferably, the specific steps of the process are: adding o-chlorobenzyl alcohol to a solvent, then adding silicon titanium molecular sieve thereto, adding an oxidant to the reaction system, stirring and reacting at 20-50° C. for 2-5 hours, cooling after the reaction, filtering to remove the catalyst, recovering the solvent under reduced pressure, and distilling to obtain high-purity o-chlorobenzaldehyde. The separated catalyst and solvent are recycled.
[0013] Preferably, the mass ratio of the catalyst to o-chlorobenzyl alcohol is 0.01-0.5:1.
[0014] Furthermore, the mass ratio of the catalyst to o-chlorobenzyl alcohol is 0.1-0.3:1.
[0015] Preferably, the oxidant is oxygen, hydrogen peroxide, tert-butyl peroxide, sodium hypochlorite or m-chloroperbenzoic acid.
[0016] Furthermore, the oxidant is oxygen or hydrogen peroxide, most preferably hydrogen peroxide.
[0017] The molar ratio of the oxidant to o-chlorobenzyl alcohol is 1-5:1, preferably 1-2:1.
[0018] Preferably, the solvent is water, acetone, THF, acetonitrile, DMF, DMA or DMSO, more preferably THF or acetonitrile. When an organic solvent is used as the solvent, the organic solvent can be recovered by vacuum distillation after the reaction is completed, and can be recycled. The volume ratio of the solvent to o-chlorobenzyl alcohol is 1-10:1, preferably 4-6:1.
[0019] Preferably, the reaction temperature is 20-100°C and the reaction time is 2-5h.
[0020] Furthermore, the reaction temperature is 30-50°C and the reaction time is 3h.
[0021] Preferably, high-purity o-chlorobenzaldehyde refers to o-chlorobenzaldehyde with a purity of 99%.
[0022] The titanium silicate molecular sieve is prepared by the following method:
[0023] Weigh 13.00g of tetrapropylammonium hydroxide and add it to a 50mL round-bottom flask, then weigh 6.70g of tetraethyl silicate and add it dropwise to the round-bottom flask, and stir at room temperature for 3h. Weigh 0.33g of tetrabutyl titanate and ultrasonically dissolve it in 1.00g of isopropanol, add it dropwise to the above round-bottom flask with a dropper, the drop rate is 0.3mL / min, and stir vigorously at room temperature for 1h. Subsequently, the reaction system is heated to 353k and stirred for 0.5h to remove ethanol and isopropanol in the solution. Weigh 0.64g of ammonium carbonate and dissolve it in 4.70g of deionized water, add it dropwise to the reaction solution, and after the system is stirred for 1h, a molar composition ratio of 1.0SiO 2 :0.03TiO 2 :0.5TPAOH:0.15(NH 4 ) 2 CO 3 : 25H 2 O of clear solution. The obtained clear solution was added to a 50mL polytetrafluoroethylene-lined stainless steel autoclave, and the autoclave was placed at 443K for hydrothermal synthesis for 48h. After the reaction was completed, the autoclave was cooled to room temperature, the obtained molecular sieve was cleaned by ultrasound and then centrifuged at high speed, and washed and centrifuged twice with ethanol and water respectively to obtain a molecular sieve sample. The obtained molecular sieve sample was dried in an oven at a temperature of 353K to remove the moisture therein, and after it was completely dried, it was calcined at 823K for 6h to obtain a silicon titanium molecular sieve as a white powder.
[0024] Beneficial effects: (1) The synthesis process of the present invention is simple and convenient, and o-chlorobenzaldehyde can be obtained by oxidation in one step, and the only by-product is water. The catalyst and the solvent can be recycled, and no polluting waste is discharged; (2) Under the efficient catalysis of titanium silicon molecular sieve, the reaction is carried out at a relatively low temperature, and the conversion rate of o-chlorobenzyl alcohol is as high as 99%, the yield of o-chlorobenzaldehyde is as high as 97%, and the purity of o-chlorobenzaldehyde is as high as 99%. The reaction is efficient and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 The basic unit structure and physical picture of silicon titanium molecular sieve;
[0026] Figure 2 The mass spectrum of o-chlorobenzaldehyde compound was obtained, indicating that the compound was successfully prepared.
[0027] Figure 3 The gas chromatography detection result diagram of the o-chlorobenzaldehyde compound was obtained, indicating that the prepared o-chlorobenzaldehyde has high purity and can be commercialized.
[0028] Figure 4 Scanning diagram for the preparation of silicon titanium molecular sieve.
[0029] Figure 5 This is a transmission diagram of the prepared silicon titanium molecular sieve.
[0030] Figure 6 This is the XRD electron microscope image of the prepared silicon titanium molecular sieve.
[0031] Figure 7 This is the IR diagram of the prepared silicon titanium molecular sieve.
[0032] Note: Figure 4-7 This indicates that silicon-titanium molecular sieve was successfully prepared. DETAILED DESCRIPTION
[0033] The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and essence of the present invention, modifications and substitutions made to the method, steps or conditions of the present invention all belong to the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.
[0034] Example 1
[0035] At room temperature, add o-chlorobenzyl alcohol (100 mmol, 14.2 g) to a round-bottom flask and dissolve it in 50 mL THF. Then add silicon titanium molecular sieve (1.4 g, 10%) and slowly add H 2 O 2 (30%, 120mmol, 12.4mL). The mixed reaction system was stirred at 50℃ for 5h. After the reaction solution was cooled, the catalyst was filtered and recovered, and the organic solvent was removed by vacuum distillation. The recovered catalyst and solvent were recycled. Then high-purity o-chlorobenzaldehyde (98%) was obtained by rectification. GC analysis showed that the conversion rate of o-chlorobenzyl alcohol reached 80%, and the yield of o-chlorobenzaldehyde was 62%.
[0036] Example 2
[0037] At room temperature, o-chlorobenzyl alcohol (100 mmol, 14.2 g) was dissolved in 50 mL THF in a round-bottom flask, and silicon titanium molecular sieve (2.84 g, 20%) was added dropwise. 30% H 2 O 2 (30%, 100mmol, 10.3mL). The mixed reaction system was stirred at 50℃ for 5h. After the reaction solution was cooled, the catalyst was filtered and recovered, and the organic solvent was removed by vacuum distillation. The catalyst and solvent were recycled, and then high-purity o-chlorobenzaldehyde (98%) was obtained by vacuum distillation. GC analysis showed that the conversion rate of o-chlorobenzyl alcohol reached 90%, and the yield of o-chlorobenzaldehyde was 88%.
[0038] Example 3
[0039] At room temperature, o-chlorobenzyl alcohol (100 mmol, 14.2 g) was dissolved in 50 mL THF in a round-bottom flask, and silicon titanium molecular sieve (4.26 g, 30%) was added dropwise. 30% H 2 O 2 (30%, 150mmol, 15.3mL). The mixed reaction system was stirred at 30℃ for 2h. After the reaction solution was cooled, the catalyst was filtered to remove the catalyst, and the organic solvent was removed by vacuum distillation. The catalyst and solvent were recycled and then distilled to obtain high-purity o-chlorobenzaldehyde (99%). GC analysis showed that the conversion rate of o-chlorobenzyl alcohol reached 90%, and the yield of o-chlorobenzaldehyde was 83%.
[0040] Example 4
[0041] At room temperature, add o-chlorobenzyl alcohol (100 mmol, 14.2 g) dissolved in 50 mL THF in a round-bottom flask, then add silicon titanium molecular sieve (4.26 g, 30%), and slowly add H 2 O 2 (30%, 120mmol, 12.4mL). The mixed reaction system was stirred at 30℃ for 3h. After the reaction solution was cooled, the catalyst was filtered to remove the catalyst, and the organic solvent was removed by vacuum distillation. The catalyst and solvent were recovered and recycled. Then high-purity o-chlorobenzaldehyde (99%) was obtained by vacuum distillation. GC analysis showed that the conversion rate of o-chlorobenzyl alcohol reached 98%, and the yield of o-chlorobenzaldehyde was 96%.
[0042] Example 5
[0043] At room temperature, o-chlorobenzyl alcohol (100 mmol, 14.2 g) was dissolved in 50 mL THF in a round-bottom flask, and silicon titanium molecular sieve (4.26 g, 30%) was added, and H 2 O 2 (30%, 150mmol, 15.3mL). The mixed reaction system was stirred at 30℃ for 3h. After the reaction solution was cooled, the catalyst was filtered to remove the catalyst, and the organic solvent was removed by vacuum distillation. The catalyst and solvent were recycled and then distilled to obtain high-purity o-chlorobenzaldehyde (99%). GC analysis showed that the conversion rate of o-chlorobenzyl alcohol reached 99%, and the yield of o-chlorobenzaldehyde was 97%.
[0044] Example 6
[0045] At room temperature, o-chlorobenzyl alcohol (100 mmol, 14.2 g) dissolved in 50 mL DMSO and titanium sieve (4.26 g, 30%) were added to a round-bottom flask. 30% H 2 O 2(30%, 150mmol, 15.3mL). The mixed reaction system was stirred at 50℃ for 5h. After the reaction solution was cooled, the catalyst was filtered to remove, and the organic solvent was removed by vacuum distillation. Then, high-purity o-chlorobenzaldehyde (97%) was obtained by vacuum distillation. GC analysis showed that the conversion rate of o-chlorobenzyl alcohol was 73% and the yield of o-chlorobenzaldehyde was 69%.
[0046] Example 7
[0047] At room temperature, o-chlorobenzyl alcohol (100 mmol, 14.2 g) was dissolved in 50 mL of acetonitrile, and silicon titanium molecular sieve (1.42 g, 10%) was added to a round-bottom flask. 30% H 2 O 2 (30%, 120mmol, 12.3mL). The mixed reaction system was stirred at 60℃ for 5h. After the reaction solution was cooled, the catalyst was filtered to remove the catalyst, and the organic solvent was removed by vacuum distillation. The catalyst and solvent were recycled and then distilled to obtain high-purity o-chlorobenzaldehyde (99%). GC analysis showed that the conversion rate of o-chlorobenzyl alcohol was 75%, and the yield of o-chlorobenzaldehyde was 68%.
[0048] Example 8
[0049] At room temperature, o-chlorobenzyl alcohol (100 mmol, 14.2 g) was dissolved in 50 mL of acetonitrile in a round-bottom flask, and silicon titanium molecular sieve (2.84 g, 20%) was added dropwise. 30% H 2 O 2 (30%, 150mmol, 15.3mL). The mixed reaction system was stirred at 30℃ for 5h. After the reaction solution was cooled, the catalyst was filtered to remove the catalyst, and the organic solvent was removed by vacuum distillation. The catalyst and solvent were recovered for recycling, and then high-purity o-chlorobenzaldehyde (99%) was obtained by rectification. GC analysis showed that the conversion rate of o-chlorobenzyl alcohol reached 92%, and the yield of o-chlorobenzaldehyde was 90%.
[0050] Example 9
[0051] At room temperature, o-chlorobenzyl alcohol (100 mmol, 14.2 g) was dissolved in 50 mL of acetone in a round-bottom flask, and silicon titanium molecular sieve (4.26 g, 30%) was added dropwise. 30% H 2 O 2 (30%, 150mmol, 15.3mL). The mixed reaction system was stirred at 56°C for 5h. After the reaction solution was cooled, the catalyst was filtered to remove the catalyst, and the organic solvent was removed by vacuum distillation. The catalyst and solvent were recovered for recycling, and then distilled to obtain high-purity o-chlorobenzaldehyde (99%). The conversion rate of o-chlorobenzyl alcohol was 84% and the yield of o-chlorobenzaldehyde was 80% according to GC analysis.
[0052] Example 10
[0053] At room temperature, o-chlorobenzyl alcohol (100 mmol, 14.2 g) was dissolved in 50 mL of H 2 O, silicon titanium molecular sieve (4.26 g, 30%), and 30% H 2 O 2 (30%, 150mmol, 15.3mL). The mixed reaction system was stirred at 80℃ for 5h. After the reaction solution was cooled, the catalyst was filtered to remove the catalyst, the solvent was removed by vacuum distillation, the catalyst was recovered and recycled, and then high-purity o-chlorobenzaldehyde (98%) was obtained by rectification. GC analysis showed that the conversion rate of o-chlorobenzyl alcohol was 71% and the yield of o-chlorobenzaldehyde was 67%.
Claims
1. A synthesis process of o-chlorobenzaldehyde catalyzed by titanium silicon molecular sieve, characterized in that: The process uses o-chlorobenzyl alcohol as a starting material and titanium silicon molecular sieve as a catalyst, and prepares high-purity o-chlorobenzaldehyde through a one-step oxidation reaction in an oxidant and a solvent; The specific steps of the process are: adding o-chlorobenzyl alcohol to a solvent at room temperature, then adding titanium silicon molecular sieve thereto, adding an oxidant to the reaction system, stirring and reacting at 20-80° C. for 2-5 hours, cooling after the reaction, filtering to remove the catalyst, and vacuum distilling to obtain high-purity o-chlorobenzaldehyde; The mass ratio of catalyst to o-chlorobenzyl alcohol is 0.01-0.5:1; The oxidant is oxygen, hydrogen peroxide, tert-butyl peroxide, sodium hypochlorite or m-chloroperbenzoic acid, and the molar ratio of the oxidant to o-chlorobenzyl alcohol is 1-5:1; The titanium silicate molecular sieve is prepared by the following method: 13.00 g of tetrapropylammonium hydroxide was weighed and added to a 50 mL round-bottom flask, and then 6.70 g of tetraethyl silicate was weighed and added dropwise to the round-bottom flask and stirred at room temperature for 3 h. 0.33 g of tetrabutyl titanate was weighed and dissolved in 1.00 g of isopropanol by ultrasonication, and the isopropanol solution of tetrabutyl titanate was added dropwise to the above round-bottom flask with a dropper at a dropping rate of 0.3 mL / min, and vigorously stirred at room temperature for 1 h. Subsequently, the reaction system was heated to 353 K and stirred for 0.5 h to remove ethanol and isopropanol in the solution. 0.64 g of ammonium carbonate was weighed and dissolved in 4.70 g of deionized water, and then added dropwise to the reaction solution. After the system was stirred for 1 h, a clear solution with a molar composition ratio of 1.0 SiO2: 0.03 TiO2: 0.5 TPAOH: 0.15 (NH4)2CO3: 25 H2O was obtained. The obtained clear solution was added to 50 mL of polytetrafluoroethylene-lined stainless steel high-pressure reactor, and then place the reactor at 443 K for 48 h of hydrothermal synthesis; after the reaction is completed, wait for the reactor to cool to room temperature, clean the obtained molecular sieve by ultrasonic cleaning and high-speed centrifugation, and wash and centrifuge it twice with ethanol and water respectively to obtain a molecular sieve sample; the obtained molecular sieve sample is dried in an oven at a temperature of 353 K to remove moisture therein, and after it is completely dried, it is calcined at 823 K for 6 h to obtain a silicon-titanium molecular sieve as a white powder.
2. The synthesis process of o-chlorobenzaldehyde catalyzed by titanium silicon molecular sieve according to claim 1, characterized in that: The solvent is water, acetone, acetonitrile, DMF, DMA, DMSO or THF.
3. The synthesis process of o-chlorobenzaldehyde catalyzed by titanium silicon molecular sieve according to claim 1, characterized in that: The volume ratio of the solvent to o-chlorobenzyl alcohol is 1-10:1.