A process for the preparation of benzenephosphonic dichloride
By combining a nano-silica-supported ionic liquid catalyst with hydrogen peroxide, the environmental pollution and low efficiency problems in the preparation of phenylphosphonic dichloride in the prior art have been solved, realizing a highly efficient and environmentally friendly method for the preparation of phenylphosphonic dichloride.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YIDU JINCHEN BIOCHEMICAL CO LTD
- Filing Date
- 2023-03-16
- Publication Date
- 2026-07-07
AI Technical Summary
Existing methods for preparing phenylphosphonic dichloride suffer from problems such as low atom utilization, numerous byproducts, and severe environmental pollution. Traditional methods use toxic reagents and involve complex processes.
A nano-silica-supported ionic liquid catalyst was used, with 30% hydrogen peroxide as the oxidant, to directly oxidize phenylphosphine dichloride to prepare phenylphosphonic dichloride under solvent-free conditions. The catalyst can be recycled.
The preparation of phenylphosphonic dichloride with high selectivity and high yield was achieved. The catalyst has good stability, the reaction process is environmentally friendly with no waste generation, and the product quality is high.
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Figure CN117430631B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a novel method for the selective oxidation of phenylphosphine dichloride to phenylphosphonic dichloride using nano-silica-supported ionic liquid catalysis, belonging to the field of chemical technology. Technical Background
[0002] Benzyl dichloride is an important chemical raw material with wide industrial applications, widely used in the synthesis of various phosphine-based flame retardants and organophosphorus intermediates (CN213131965U; CN113644240A; EP0046653A1; US4672125A). The industrial production process of phenylphosphine dichloride mainly uses phenylphosphine dichloride as a raw material and prepares it through an oxidation reaction. Traditional methods utilize phenylphosphine dichloride through chlorination followed by oxidation with sulfur dioxide or phosphorus pentoxide. However, these methods require various hazardous chemicals such as chlorine, carbon tetrachloride, and sulfur dioxide or phosphorus pentoxide, and also produce byproducts such as thiodichlorosulfonyl. These methods suffer from low atom utilization, numerous byproducts, and serious environmental pollution. The direct oxidation of phenylphosphine dichloride to prepare phenylphosphine dichloride has attracted widespread attention from chemists both domestically and internationally due to its green nature and high atom economy. Ji Quan et al. reported a new process for the direct oxidation of phenylphosphine dichloride to phenylphosphonic dichloride in the presence of a catalyst. A measured amount of phenylphosphonic acid, carbon tetrachloride, and charcoal were added to phenylphosphine dichloride for the oxidation reaction. However, this method still inevitably uses toxic reagents such as carbon tetrachloride, which can easily cause environmental pollution (Journal of Qingdao University, 1996, 11(4): 15-17; Sichuan Chemical Industry, 2004, 7(4): 36, 37, 55). Using hydrogen peroxide as an oxidant has less environmental harm and is clean and environmentally friendly. The only byproduct in the reaction is water, which has advantages such as high conversion rate, short process route, and high atom economy. Therefore, it is considered a clean oxidation route with broad application prospects.
[0003] In view of the shortcomings of the existing technology, there is an urgent need for a new method to prepare phenylphosphonic dichloride in order to overcome the deficiencies of the existing technology. Summary of the Invention
[0004] The purpose of this invention is to develop a green and efficient method for the direct selective oxidation of phenylphosphine dichloride to prepare phenylphosphonic dichloride.
[0005] To achieve the above objectives, the present invention provides a novel method for the selective oxidation of phenylphosphine dichloride with hydrogen peroxide to produce phenylphosphonic dichloride, namely, using phenylphosphine dichloride as raw material, 30% hydrogen peroxide as oxidant, and nano-silica-supported ionic liquid as catalyst, to achieve the selective oxidation reaction of phenylphosphine dichloride under solvent-free conditions.
[0006] The catalytic reaction principle of this invention is as follows:
[0007]
[0008] The catalyst is a nano-silica supported ionic liquid.
[0009] The preparation method of the nano-silica-supported N-methylpyrrolidone ionic liquid used in this invention can be found in the literature (J.Mex.Chem.Soc.2018, doi:http: / / dx.doi.org / 10.29356 / jmcs.v62i1.584), and its chemical structure is as follows:
[0010]
[0011] SiO2@NMPIL-anion
[0012] anion = NTf2,PF6,H2PMo 12 O 40
[0013] In the general formula, the anion can be NTf2, PF6, or H2PMo. 12 O 40 .
[0014] The present invention is characterized by using phenylphosphine dichloride as raw material, 30% hydrogen peroxide as oxidant, and nano-silica-supported N-methylpyrrolidone ionic liquid as catalyst, wherein the materials and catalyst are fed and mixed in proportion and stirred to react.
[0015] The molar ratio of the materials used in this invention is phenylphosphine dichloride: 30% hydrogen peroxide = 1:1 to 2, more preferably 1:1 to 1.5.
[0016] The amount of catalyst used in this invention is 2-25% of the mass of phenylphosphine dichloride, more preferably 2-15%.
[0017] The reaction temperature described in this invention is 20–70°C, more preferably 20–50°C.
[0018] The reaction time described in this invention is 1 to 6 hours, more preferably 1 to 4 hours.
[0019] The catalysts described in this invention are nano-silica supported N-methylpyrrolidone ionic liquids: SiO2@NMPIL-NTf2, SiO2@NMPIL-PF6, and SiO2@NMPIL-H2PMo. 12 O 40 One of them, preferably SiO2@NMPIL-H2PMo 12 O 40 .
[0020] This invention discloses a method for the selective oxidation of phenylphosphine dichloride to phenylphosphonic dichloride using a nano-silica-supported N-methylpyrrolidone ionic liquid. After the reaction, the mixture is cooled and allowed to settle. The catalyst particles settle to the bottom of the flask, and the catalyst and product phases are separated by filtration. The catalyst can be recovered and reused for the next batch of catalytic oxidation reactions after washing with dichloromethane. The dichloromethane phase of the filtrate is then used to recover the solvent, yielding the oxidation product phenylphosphine dichloride.
[0021] The key technology of the method for preparing phenylphosphonic dichloride according to the present invention is to use nano-silica-supported N-methylpyrrolidone ionic liquid to catalyze the selective oxidation reaction of phenylphosphine dichloride with hydrogen peroxide to obtain phenylphosphonic dichloride.
[0022] The beneficial effects of this invention are as follows: Compared with the prior art, this invention has the following advantages: (1) It constructs a novel catalytic oxidation reaction system of nano-silica-supported N-methylpyrrolidone ionic liquid. This catalytic system has good stability and can be well recycled. (2) The catalytic reaction system has high catalytic activity, high reaction selectivity, good product quality, and high yield. (3) Traditional reaction processes have environmental problems such as waste treatment. This reaction system is simple to operate, and the reaction process only generates products and water. No other organic solvents are added during the reaction process, making the system environmentally friendly. Attached Figure Description
[0023] Figure 1 SEM image of the preferred catalyst SiO2@NMPIL-H2PMo12O40 before reaction;
[0024] Figure 2 SEM image of the preferred catalyst SiO2@NMPIL-H2PMo12O40 after 4 recycling cycles;
[0025] Figure 3 The gas chromatogram of the product with the best quality obtained in Example 2;
[0026] Figure 4 The infrared spectrum of the product with the best quality obtained in Example 2;
[0027] Figure 5 The image shows the 1H-NMR spectrum of the product with the best quality obtained in Example 2. Detailed Implementation
[0028] The following embodiments are merely descriptions of the best embodiments of the present invention and do not limit the scope of the present invention in any way. The essence of the present invention is further explained through the following examples.
[0029] Example 1
[0030] In a reaction flask, 0.5 mol of phenylphosphine dichloride and 8.0 g of SiO2@NMPIL-NTf2 were added. 0.6 mol of 30% hydrogen peroxide was slowly added with stirring, and the reaction was continued at 50°C for 4 hours with stirring. The catalyst was recovered by cooling and filtration. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonyl dichloride in 52% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 91.2%.
[0031] Example 2
[0032] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo 12 O 40 (6.0 g) of the catalyst was slowly added with 30% hydrogen peroxide (0.6 mol) under stirring, and the reaction was continued at 40 °C for 3 hours with stirring. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 81% yield. GC and... 1 H-NMR analysis results showed a purity of 97.8%.
[0033] Example 3
[0034] In a reaction flask, 0.5 mol of phenylphosphine dichloride and 9.0 g of SiO2@NMPIL-PF6 were added. 0.6 mol of 30% hydrogen peroxide was slowly added with stirring, and the reaction was continued at 50°C for 4 hours with stirring. The catalyst was recovered by cooling and filtration. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonyl dichloride in 57% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 92.7%.
[0035] Example 4
[0036] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo 12 O 40 (6.0 g) of the catalyst was slowly added with 30% hydrogen peroxide (0.7 mol) under stirring, and the reaction was continued at 45 °C for 3 hours with stirring. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 75% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 95.2%.
[0037] Example 5
[0038] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo12 O 40 (6.0 g) of the catalyst was slowly added with 30% hydrogen peroxide (0.5 mol) under stirring, and the reaction was continued at 40 °C for 3 hours with stirring. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 76% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 97.3%.
[0039] Example 6
[0040] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo 12 O 40 (5.0 g) of phenylphosphonic acid was slowly added with stirring to a solution of 30% hydrogen peroxide (0.55 mol). The reaction was then continued at 40 °C with stirring for 5 hours. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 70% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 97.1%.
[0041] Example 7
[0042] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo 12 O 40 (7.0 g) of the catalyst was slowly added with 30% hydrogen peroxide (0.55 mol) under stirring, and the reaction was continued at 40 °C with stirring for 4 hours. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 77% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 96.4%.
[0043] Example 8
[0044] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo 12 O 40 (5.0 g) of phenylphosphonic acid was slowly added with stirring to a solution of 30% hydrogen peroxide (0.6 mol). The reaction was then continued at 40 °C with stirring for 4 hours. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 79% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 96.8%.
[0045] Example 9
[0046] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo 12 O 40 (6.0 g) of the catalyst was slowly added with 30% hydrogen peroxide (0.8 mol) under stirring, and the reaction was continued at 40 °C for 3 hours with stirring. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 74% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 95.2%.
[0047] Example 10
[0048] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo 12 O 40 (3.0 g) of the catalyst was slowly added with 30% hydrogen peroxide (0.6 mol) under stirring, and the reaction was continued at 50 °C for 6 hours with stirring. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 57% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 94.5%.
[0049] Example 11
[0050] In a reaction flask, add 0.5 mol of phenylphosphine dichloride, SiO2@NMPIL-H2PMo 12 O 40 (6.0 g) of the catalyst was slowly added with 30% hydrogen peroxide (0.6 mol) under stirring, and the reaction was continued at 60 °C for 3 hours with stirring. The catalyst was cooled, filtered, and recovered. The catalyst was washed with dichloromethane, and the filtrate was distilled to recover dichloromethane, yielding phenylphosphonic dichloride in 71% yield. GC and... 1 H-NMR analysis was the same as in Example 2, with a purity of 93.2%.
[0051] Example 12
[0052] After the reaction was completed, the mixture was cooled and allowed to stand. The catalyst particles settled at the bottom of the flask, and the catalyst and product phases were separated by filtration. The catalyst could be recovered and reused for the next batch of catalytic oxidation reactions after washing with dichloromethane. The catalyst from Example 2 was recovered and the catalytic reaction was carried out under the conditions of Example 2. 0.5 mol of phenylphosphine dichloride was added, followed by the slow addition of 0.6 mol of 30% hydrogen peroxide, and the reaction was continued at 40°C with stirring for 3 hours. The recovered catalyst was reused four times, and the experimental results showed that the catalyst activity did not decrease. The yields of phenylphosphine dichloride were 80%, 77%, 76%, and 72%, respectively. GC and 1The H-NMR analysis was the same as in Example 2, with purities of 97.5%, 97.2%, 96.7%, and 96.0%, respectively.
Claims
1. A method for preparing phenylphosphonic dichloride, characterized in that, Using phenylphosphine dichloride as a raw material and 30% hydrogen peroxide as an oxidant, after adding a nano-silica-supported N-methylpyrrolidone ionic liquid catalyst, without adding other solvents, the reaction was carried out at 20-70 degrees Celsius for 1-6 hours with stirring, followed by cooling and filtration to separate the product phenylphosphonic dichloride. The structure of the nano-silica-supported N-methylpyrrolidone ionic liquid is as follows: The anion is NTF2, PF6, or H2PMo. 12 O 40 .
2. The method according to claim 1, characterized in that, The molar ratio of the materials used is phenylphosphine dichloride: 30% hydrogen peroxide = 1: 1~2.
3. The method according to claim 2, characterized in that, The molar ratio of the materials used is phenylphosphine dichloride: 30% hydrogen peroxide = 1: 1~1.
5.
4. The method according to claim 1, characterized in that, The amount of supported ionic liquid catalyst used is 2-25% of the mass of phenylphosphine dichloride.
5. The method according to claim 4, characterized in that, The amount of supported ionic liquid catalyst used is 2-15% of the mass of phenylphosphine dichloride.
6. The method according to claim 1, characterized in that, The reaction temperature is 20~70 degrees Celsius.
7. The method according to claim 6, characterized in that, The reaction temperature is 20~50 degrees Celsius.
8. The method according to claim 1, characterized in that, The reaction time is 1 to 6 hours.
9. The method according to claim 8, characterized in that, The reaction time is 1 to 4 hours.
10. The method according to claim 1, characterized in that, After the reaction is complete, the product and catalyst can be separated by filtration. The catalyst can be recovered and reused for the next batch of catalytic oxidation reaction by washing with dichloromethane. The filtrate product can be recovered by solvent recovery in dichloromethane to obtain the oxidation product phenylphosphonic dichloride.