Green preparation method and application of diphenylphosphine oxide

Abstract

The invention provides a green preparation method and application of diphenyl phosphine oxide. The preparation method comprises the following steps: step 1, mixing diphenyl alkoxy phosphine, water and Lewis acid, and fully stirring for reaction to obtain a reaction solution containing diphenyl phosphine oxide and alcohol; step 2, distilling the reaction liquid, washing with water, standing, separating liquid, collecting an organic phase, drying the organic phase, and cooling and crystallizing to obtain diphenylphosphine oxide; and step 3, rectifying and purifying the distilled alcohol, and pumping the distilled acid and water washing liquid into a reaction kettle for cyclic catalysis. The diphenylalkoxyphosphine is used as a raw material and is subjected to hydrolysis reaction with water under the catalysis of the lewis acid to generate diphenylphosphine oxide and alcohol, the lewis acid can be continuously returned to the reaction kettle to participate in the reaction after being subjected to subsequent distillation, the synthesis process is simple, the atom economy is high, the reaction principle is simple, the conditions are easy to control, and the method is green and environment-friendly and can be used for industrial production.

Description

Technical Field

[0001] This invention relates to the field of phosphorus chemical synthesis technology, specifically to a green preparation method for diphenylphosphine oxide and its application. Background Technology

[0002] Diphenylphosphine oxide is an important intermediate in organic synthesis. Its molecular structure consists of two benzene rings connected by a phosphorus-oxygen double bond (P=O) to form a rigid planar structure, exhibiting both electronic effects and steric hindrance properties, making it a versatile agent in organic synthesis and materials science. It is widely used in the synthesis of chiral phosphine ligands, pesticides, electronic materials, lithium battery electrolyte additives, and phosphorus-containing flame retardants. It can also replace alkali metal cyanides as coupling agents in the synthesis of heterocyclic compounds.

[0003] The main methods for synthesizing diphenylphosphine oxide include the following: (1) using phosphorus oxychloride and benzene as raw materials, followed by Friedel-Crafts alkylation and reduction with lithium aluminum hydride to obtain the target product; (2) using diethyl phosphite as raw material, reacting with Grignard reagents phenyl magnesium chloride or phenyl magnesium bromide to generate the product; among them, methods (1) and (2) both have the disadvantages of complex operation, difficult post-processing, high risk and large amount of waste; (3) using phosphorus trichloride as raw material, obtaining diphenylphosphine chloride after Friedel-Crafts alkylation, and then obtaining the target product after appropriate hydrolysis, but the purification of the intermediate diphenylphosphine chloride is relatively difficult and the yield is low; (4) using Ph3P(O) as raw material, obtaining the target product by hydrolysis under the reduction of metallic sodium, but the high reactivity, flammability and storage difficulty of metallic sodium pose certain risks.

[0004] To address the aforementioned issues, a green process route that is simple to operate, produces less waste, and has high atom economy is urgently needed. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a green preparation method for diphenylphosphine oxide and its application, solving the problems mentioned in the background section.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] According to a first aspect of the present invention, a green method for preparing diphenylphosphine oxide is provided, comprising the following steps:

[0010] Step 1: Mix diphenylalkoxyphosphine, water and Lewis acid, and stir the mixture thoroughly to obtain a reaction solution containing diphenylphosphine oxygen and alcohol;

[0011] Step 2: Distill the reaction solution, wash with water, allow it to stand and separate the organic phase, dry the organic phase, cool and crystallize to obtain diphenylphosphine oxide;

[0012] Step 3: Purify the distilled alcohol by distillation, and pump the distilled acid and washing liquid into the reaction vessel for cyclic catalysis.

[0013] The diphenylalkoxyphosphine in this invention undergoes hydrolysis under Lewis acid catalysis, and the reaction equation is shown in Formula I:

[0014]

[0015] Preferably, in step 1, the diphenylalkoxyphosphine is selected from diphenylmethoxyphosphine or diphenylethoxyphosphine.

[0016] Preferably, in step 1, the Lewis acid is selected from at least one of trifluoroacetic acid, trifluoromethanesulfonic acid, acetic acid, and propionic acid.

[0017] Preferably, in step 1, the reaction temperature is 25–55°C and the reaction time is 30–90 min.

[0018] Preferably, in step 1, the mass ratio of water to diphenylalkoxyphosphine and Lewis acid is 18:216-230:0.62-1.5.

[0019] Preferably, in step 2, the distillation includes a first-stage distillation and a second-stage distillation, wherein the first-stage distillation is an alcohol distillation and the second-stage distillation is an acid distillation.

[0020] According to a second aspect of the present invention, the application of diphenylphosphine oxide in pesticides, chiral phosphorus ligands, and phosphine oxide flame retardants is provided.

[0021] According to a third aspect of the present invention, the application of diphenylphosphine oxide in electronic materials and as an additive for lithium battery electrolytes is provided.

[0022] Beneficial effects

[0023] This invention provides a green preparation method for diphenylphosphine oxide and its application. It has the following beneficial effects:

[0024] This solution provides a green preparation method for diphenylphosphine oxide, which uses diphenylalkoxyphosphine as a raw material and undergoes a hydrolysis reaction with water under Lewis acid catalysis to generate diphenylphosphine oxide and alcohol. The Lewis acid can be returned to the reactor for further reaction after subsequent distillation. The synthesis process is simple, has high atom economy, simple reaction principle, easy-to-control conditions, and is green and environmentally friendly, making it suitable for industrial production. Attached Figure Description

[0025] Figure 1This is a flow chart of the green synthesis process of diphenylphosphine oxide according to the present invention. Detailed Implementation

[0026] To facilitate understanding of the present invention, it will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to make the disclosure of the present invention more thorough and complete.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein in the specification of the invention is for the purpose of describing particular embodiments or examples only and is not intended to limit the invention.

[0028] The following specific examples further illustrate the green preparation method of diphenylphosphine oxide according to the present invention. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific conditions are not specified in the examples, they were performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0029] Example 1

[0030] A green preparation method for diphenylphosphine oxide, the process flow diagram is as follows: Figure 1 As shown, it includes the following steps:

[0031] Step 1: Add 216 kg of diphenylmethoxyphosphine, 18 kg of water, and 1.5 kg of trifluoromethanesulfonic acid to the reaction vessel, turn on the stirrer and react at 25°C for 30 min. After the reaction is complete, a reaction solution containing diphenylphosphine oxide and methanol is generated.

[0032] Step 2: First, distill off 30 kg of methanol from the reaction solution at 65.4℃, then distill off 1.4 kg of trifluoromethanesulfonic acid at 162℃. Then, add 18 kg of water to wash away the residual trifluoromethanesulfonic acid and methanol in the reaction solution. Let it stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 200 kg of diphenylphosphine oxide with a purity of 98%.

[0033] Step 3: The 30 kg of distilled methanol is further purified by distillation in a distillation column to obtain 26 kg of by-product methanol with a purity of 99.5%. The 1.4 kg of distilled trifluoromethanesulfonic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0034] Example 2

[0035] Step 1: Add 216 kg of diphenylmethoxyphosphine, 18 kg of water, and 1.14 kg of trifluoroacetic acid to the reaction vessel, turn on the stirrer, and react at 25°C for 30 min. After the reaction is complete, a reaction solution containing diphenylphosphine oxide and methanol is generated.

[0036] Step 2: First, distill off 28 kg of methanol from the reaction solution at 65.4℃, then distill off 1.08 kg of trifluoroacetic acid at 72.4℃. Then, add 18 kg of water to wash away the residual trifluoroacetic acid and methanol in the reaction solution. Let it stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 195.9 kg of diphenylphosphine oxide with a purity of 98%.

[0037] Step 3: The 28 kg of distilled methanol is further purified by distillation in a distillation column to obtain 25 kg of by-product methanol with a purity of 99.5%. The 1.08 kg of distilled trifluoroacetic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0038] Example 3

[0039] Step 1: Add 216 kg of diphenylmethoxyphosphine, 18 kg of water, and 0.62 kg of acetic acid to the reaction vessel, turn on the stirrer, and react at 25°C for 30 min. After the reaction is complete, a reaction solution containing diphenylphosphine oxide and methanol is generated.

[0040] Step 2: First, distill off 27.5 kg of methanol from the reaction solution at 65.4℃, then distill off 0.6 kg of acetic acid at 117℃. Then, add 18 kg of water to wash away the acetic acid and methanol in the residual reaction solution. Let stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 195.5 kg of diphenylphosphine oxide with a purity of 97.5%.

[0041] Step 3: The 27.5 kg of distilled methanol is further purified by distillation in a distillation column to obtain 25 kg of by-product methanol with a purity of 99.5%. The 0.6 kg of distilled acetic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0042] Example 4

[0043] Step 1: Add 216 kg of diphenylmethoxyphosphine, 18 kg of water, and 0.74 kg of propionic acid to the reaction vessel, start stirring and react at 25°C for 30 min. After the reaction is complete, a reaction solution containing diphenylphosphine oxide and methanol is generated.

[0044] Step 2: First, distill off 28 kg of methanol from the reaction solution at 65.4℃, then distill off 0.68 kg of propionic acid at 141℃. Then, add 18 kg of water to wash away the propionic acid and methanol in the residual reaction solution. Let it stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 190.5 kg of diphenylphosphine oxide with a purity of 96%.

[0045] Step 3: The 28 kg of distilled methanol is further purified by distillation in a distillation column to obtain 24.2 kg of by-product methanol with a purity of 99.5%. The 0.68 kg of distilled propionic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0046] Example 5

[0047] Step 1: Add 230 kg of diphenylethoxyphosphine, 18 kg of water, and 1.5 kg of trifluoromethanesulfonic acid to the reaction vessel, turn on the stirrer, and react at 25°C for 30 min. After the reaction is complete, a reaction solution containing diphenylethoxyphosphine and ethanol is generated.

[0048] Step 2: First, distill off 45 kg of ethanol from the reaction solution at 78 °C, then distill off 1.4 kg of trifluoromethanesulfonic acid at 162 °C. Then, add 18 kg of water to wash away the residual trifluoromethanesulfonic acid and ethanol from the reaction solution. Allow the solution to stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 200.1 kg of diphenylphosphine oxide with a purity of 98.5%.

[0049] Step 3: The 45 kg of distilled ethanol is further purified by distillation in a distillation column to obtain 42 kg of by-product ethanol with a purity of 99.5%. The 1.4 kg of distilled trifluoromethanesulfonic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0050] Example 6

[0051] Step 1: Add 230 kg of diphenylethoxyphosphine, 18 kg of water, and 1.5 kg of trifluoromethanesulfonic acid to the reaction vessel, turn on the stirrer and react at 25°C for 60 min. After the reaction is complete, a reaction solution containing diphenylethoxyphosphine and ethanol is generated.

[0052] Step 2: First, distill off 44.5 kg of ethanol from the reaction solution at 78℃, then distill off 1.4 kg of trifluoromethanesulfonic acid at 162℃. Then, add 18 kg of water to wash away the residual trifluoromethanesulfonic acid and ethanol from the reaction solution. Allow the solution to stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 198.9 kg of diphenylphosphine oxide with a purity of 98.4%.

[0053] Step 3: The 44.5 kg of distilled ethanol is further purified by distillation in a distillation column to obtain 41.5 kg of by-product ethanol with a purity of 99.5%. The 1.4 kg of distilled trifluoromethanesulfonic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0054] Example 7

[0055] Step 1: Add 230 kg of diphenylethoxyphosphine, 18 kg of water, and 1.5 kg of trifluoromethanesulfonic acid to the reaction vessel, turn on the stirrer, and react at 25°C for 90 min. After the reaction is complete, a reaction solution containing diphenylethoxyphosphine and ethanol is generated.

[0056] Step 2: First, distill off 45.2 kg of ethanol from the reaction solution at 78℃, then distill off 1.4 kg of trifluoromethanesulfonic acid at 162℃. Then, add 18 kg of water to wash away the residual trifluoromethanesulfonic acid and ethanol from the reaction solution. Allow the solution to stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 199.2 kg of diphenylphosphine oxide with a purity of 98.6%.

[0057] Step 3: The 45.2 kg of distilled ethanol is further purified by distillation in a distillation column to obtain 42.5 kg of by-product ethanol with a purity of 99.5%. The 1.4 kg of distilled trifluoromethanesulfonic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0058] Comparative Example 1

[0059] Step 1: Add 230 kg of diphenylethoxyphosphine, 18 kg of water, and 1.5 kg of trifluoromethanesulfonic acid to the reaction vessel, turn on the stirrer and react at 20°C for 20 min. After the reaction is complete, a reaction solution containing diphenylethoxyphosphine and ethanol is generated.

[0060] Step 2: First, distill off 42 kg of ethanol from the reaction solution at 78℃, then distill off 1.4 kg of trifluoromethanesulfonic acid at 162℃. Then, add 18 kg of water to wash away the residual trifluoromethanesulfonic acid and ethanol in the reaction solution. Let stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 184 kg of diphenylphosphine oxide with a purity of 96.5%.

[0061] Step 3: The 42 kg of distilled ethanol is further purified by distillation in a distillation column to obtain 40 kg of by-product ethanol with a purity of 99.5%. The 1.4 kg of distilled trifluoromethanesulfonic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0062] Comparative Example 2

[0063] Step 1: Add 230 kg of diphenylethoxyphosphine, 18 kg of water, and 1.5 kg of trifluoromethanesulfonic acid to the reaction vessel, start stirring and react at 60°C for 100 min. After the reaction is complete, a reaction solution containing diphenylethoxyphosphine and ethanol is generated.

[0064] Step 2: First, distill off 43 kg of ethanol from the reaction solution at 78℃, then distill off 1.4 kg of trifluoromethanesulfonic acid at 162℃. Then, add 18 kg of water to wash away the residual trifluoromethanesulfonic acid and ethanol in the reaction solution. Let it stand and separate the liquids. After drying the organic phase, cool and crystallize to obtain 185 kg of diphenylphosphine oxide with a purity of 97.2%.

[0065] Step 3: The 43 kg of distilled ethanol is further purified by distillation in a distillation column to obtain 41 kg of by-product ethanol with a purity of 99.5%. The 1.4 kg of distilled trifluoromethanesulfonic acid and wash water are mixed and pumped into the reactor for the next batch of synthesis.

[0066] The yields of diphenylphosphine oxide and alcohols in Examples 1 to 7 and Comparative Examples 1 to 2 were calculated respectively, as shown in Table 1.

[0067] Table 1

[0068]

[0069]

[0070] According to the data in Table 1, the yield of diphenylphosphine can be improved by optimizing the selection of raw materials and the conditions of the hydrolysis reaction. By comparison, it can be seen that diphenylethoxyphosphine is a better choice for diphenylalkoxyphosphine, and the hydrolysis reaction temperature of 25-55℃ and the time of 30-90min are more conducive to improving the yield.

[0071] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A green preparation method for diphenylphosphine oxide, characterized in that: Includes the following steps: Step 1: Mix diphenylalkoxyphosphine, water and Lewis acid, and stir the mixture thoroughly to obtain a reaction solution containing diphenylphosphine oxygen and alcohol; Step 2: Distill the reaction solution, wash with water, allow it to stand and separate the organic phase, dry the organic phase, cool and crystallize to obtain diphenylphosphine oxide; Step 3: Purify the distilled alcohol by distillation, and pump the distilled acid and washing liquid into the reaction vessel for cyclic catalysis.

2. The green preparation method of diphenylphosphine oxide according to claim 1, characterized in that: In step 1, the diphenylalkoxyphosphine is selected from diphenylmethoxyphosphine or diphenylethoxyphosphine.

3. The green preparation method of diphenylphosphine oxide according to claim 1, characterized in that: In step 1, the Lewis acid is selected from at least one of trifluoroacetic acid, trifluoromethanesulfonic acid, acetic acid, and propionic acid.

4. The green preparation method of diphenylphosphine oxide according to claim 1, characterized in that: In step 1, the reaction temperature is 25–55°C, and the reaction time is 30–90 min.

5. The green preparation method of diphenylphosphine oxide according to claim 1, characterized in that: In step 1, the mass ratio of water to diphenylalkoxyphosphine and Lewis acid is 18:216-230:0.62-1.

5.

6. The green preparation method of diphenylphosphine oxide according to claim 1, characterized in that: In step 2, the distillation includes a first-stage distillation and a second-stage distillation. The first-stage distillation is an alcohol distillation, and the second-stage distillation is an acid distillation.

7. The application of a diphenylphosphine oxide prepared by any one of claims 1 to 6 in pesticides, chiral phosphorus ligands, and phosphine oxide flame retardants.

8. The application of diphenylphosphine oxide obtained by the preparation method according to any one of claims 1 to 6 in electronic materials and lithium battery electrolyte additives.

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