Synthesis method of triphenylphosphine

Abstract

The invention relates to a synthesis method of triphenylphosphine, which belongs to the technical field of organic synthesis, and comprises the following steps: Step 1: adding a solvent, magnesium chips and an initiator into a reaction bottle, and heating to 50-60 DEG C; 2, dropwise adding a mixed solution of benzene halide and phosphorus trichloride, and after addition is completed, carrying out a heat preservation reaction; 3, after the reaction is finished, the temperature is reduced to the room temperature, water is added for washing and layering, an organic phase is concentrated, the solvent is recycled, and triphenylphosphine is obtained. According to the method, benzene halide and phosphorus trichloride are used as raw materials and react with magnesium chips through a one-pot method in a solvent to directly synthesize triphenylphosphine, compared with a traditional synthesis method, a Grignard reagent does not need to be prepared step by step, high energy consumption caused by low-temperature reaction conditions during subsequent Grignard reagent addition is not needed, the process is safer and more efficient, energy consumption can be effectively reduced, and the method is suitable for industrial production. Compared with a traditional synthesis method, the method has the advantages of no high risk of a sodium method process, safety and environmental protection pressure relief, simple overall process, high yield and suitability for industrial large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly to a method for synthesizing triphenylphosphine. Background Art

[0002] Triphenylphosphine has a wide range of uses in the field of fine chemicals. It can be used as a catalyst for fine chemical synthesis, a new type of petroleum processing catalyst, a new type of biocatalysis technology and catalyst, a new type of catalyst for organic synthesis, etc.; it can also be used as a new material for catalyst carriers and various new types of co-catalytic materials. Triphenylphosphine has great economic and social benefits, and it is very necessary to develop, produce and optimize its synthesis process.

[0003] Currently, the traditional synthesis methods mainly include the Grignard reagent method: a Grignard reagent is first prepared from halogenated benzene and magnesium chips in a solvent, then cooled to an ultra-low temperature of -40 °C, and then a solution of phosphine halide is slowly added dropwise to finally obtain a triphenylphosphine compound [Iran. Chem. Soc., 2011, 8, 240]. This synthesis method requires the prior preparation of the Grignard reagent and then the addition reaction with phosphine halide at low temperature. Its synthesis operation is dangerous, the process is complex, and the energy consumption is high. The metallic sodium method: using metallic sodium, phosphorus trichloride, and chlorobenzene as raw materials, first heating and melting metallic sodium in toluene and dispersing it into sodium sand under the action of a dispersant, and then reacting with phosphorus trichloride to obtain triphenylphosphine. This synthesis method requires the use of very dangerous excessive metallic sodium, with low safety and harsh process conditions.

[0004] Therefore, seeking an economical, environmentally friendly, safe and efficient process for synthesizing triphenylphosphine remains a research hotspot in this field. Summary of the Invention

[0005] The present invention provides a method for synthesizing triphenylphosphine, which solves the problems raised in the above background art. Using halogenated benzene and phosphorus trichloride as raw materials, reacting directly with magnesium chips in a "one-pot" manner in a solvent to obtain triphenylphosphine. This synthesis method is safer and more efficient, the process is simple, and it is suitable for industrial production.

[0006] The solution of the present invention to the above technical problems is as follows: A method for synthesizing triphenylphosphine, the synthesis method includes the following:

[0007] Step1: Add a solvent, magnesium chips and an initiator into a reaction flask. The solvent is 2-methyltetrahydrofuran, and the initiator is dibromoethane. Heat to 50 - 60 °C;

[0008] Step2: Dropwise add a mixed solution of halogenated benzene and phosphorus trichloride. X in the halogenated benzene is chlorine or bromine, and the molar ratio of halogenated benzene to phosphorus trichloride is 3.0 - 4.0:1. After adding, keep the temperature for reaction, the temperature for heat preservation is 50 - 60 °C, and the heat preservation time is 1 - 2 hours;

[0009] Step 3: After the reaction is completed, cool down to room temperature, add water for washing and stratification, and concentrate the organic phase to recover the solvent to obtain triphenylphosphine. The synthetic process route diagram is as follows:

[0010]

[0011] Based on the above technical solutions, the present invention can be further improved as follows.

[0012] Further, the reaction flask is purged with nitrogen before the reaction to control the atmosphere environment in the reaction flask, improving the reaction efficiency and product quality.

[0013] Further, the solvent can also be a single solvent or a mixed solvent of tetrahydrofuran and toluene.

[0014] Further, the halogenated benzene and phosphorus trichloride are premixed before dropping.

[0015] The beneficial effects of the present invention are as follows: The present invention provides a method for synthesizing triphenylphosphine, having the following advantages:

[0016] 1. Using halogenated benzene and phosphorus trichloride as raw materials, reacting directly with magnesium chips in a solvent by the "one-pot method" to obtain triphenylphosphine. Compared with the traditional synthesis method, there is no need for the high energy consumption of the stepwise preparation of Grignard reagent and the low-temperature reaction conditions during the subsequent addition of Grignard reagent. It is safer and more efficient in the process and can effectively reduce energy consumption.

[0017] 2. Compared with the traditional synthesis method, it does not have the high risk of the sodium method process, reducing the safety and environmental protection pressure. The overall process is simple, with a high yield, and is suitable for industrial scale-up production.

[0018] The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and implement it in accordance with the content of the description, the following takes the preferred embodiments of the present invention as detailed examples. The specific implementation manners of the present invention are given in detail by the following examples. Specific Embodiments

[0019] The principles and features of the present invention are described below. The examples cited are only for explaining the present invention and are not intended to limit the scope of the present invention. The present invention is described more specifically by way of example in the following paragraphs. The advantages and features of the present invention will be clearer according to the following description and claims.

[0020] It should be noted that when a component is referred to as "fixed to" another component, it can be directly on the other component or there can also be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are only for the purpose of illustration.

[0021] Unless otherwise defined, all technical and scientific terms used in this article have the same meaning as those commonly understood by those skilled in the technical field to which this invention belongs. The terms used in the specification of this invention are only for the purpose of describing specific embodiments and are not intended to limit this invention. The term "and / or" used in this article includes any and all combinations of one or more of the related listed items.

[0022] Example 1:

[0023] Step 1: In a reaction flask, first displace nitrogen, then add 100.0 g of the solvent 2-methyltetrahydrofuran and magnesium chips, and 2 drops of the initiator dibromoethane, and heat to 50 - 60 °C;

[0024] Step 2: Dropwise add a pre-mixed mixture of chlorobenzene (33.75 g, 0.3 mol) and phosphorus trichloride (13.73 g, 0.1 mol). After the addition is complete, keep warm for 2 hours;

[0025] Step 3: Let the reaction cool to room temperature, add water for washing and separation. The organic phase is concentrated to recover the solvent to obtain 24.8 g of triphenylphosphine, with a yield of 93.6% and a purity of 99%.

[0026] 1 H NMR (400 MHz, CDCl3) δ 7.24 - 7.34 (15H);

[0027] Example 2:

[0028] Step 1: In a reaction flask, first displace nitrogen, then add 100.0 g of the solvent 2-methyltetrahydrofuran and magnesium chips, and 2 drops of the initiator dibromoethane, and heat to 50 - 60 °C;

[0029] Step 2: Dropwise add a pre-mixed mixture of bromobenzene (47.10 g, 0.3 mol) and phosphorus trichloride (13.73 g, 0.1 mol). After the addition is complete, keep warm for 2 hours;

[0030] Step 3: The reaction was cooled to room temperature, water was added for washing and liquid separation. The organic phase was concentrated to recover the solvent, and 24.6 g of triphenylphosphine was obtained with a yield of 93.1% and a purity of 99%.

[0031] 1 H NMR (400 MHz, CDCl3) δ 7.24 - 7.34 (15H);

[0032] Example 3:

[0033] Step 1: In a reaction flask, nitrogen was first replaced, then 50.0 g of 2-methyltetrahydrofuran, 50.0 g of toluene and magnesium shavings were added, and 2 drops of initiator dibromoethane were added. The mixture was heated to 50 - 60 °C.

[0034] Step 2: A mixture of pre-mixed chlorobenzene (33.75 g, 0.3 mol) and phosphorus trichloride (13.73 g, 0.1 mol) was added dropwise. After the addition, the mixture was kept warm for 2 hours.

[0035] Step 3: The reaction was cooled to room temperature, water was added for washing and liquid separation. The organic phase was concentrated to recover the solvent, and 24.5 g of triphenylphosphine was obtained with a yield of 92.8% and a purity of 99%.

[0036] 1 H NMR (400 MHz, CDCl3) δ 7.24 - 7.34 (15H);

[0037] As described above, it is only the preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Any person skilled in the art of this industry can smoothly implement the present invention according to the above description. However, any minor changes, modifications and evolutions made by those skilled in the art within the scope of the technical solution of the present invention by using the technical content disclosed above are equivalent embodiments of the present invention. At the same time, any changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the protection of the technical solution of the present invention.

Claims

1. A method for synthesizing triphenylphosphine, the synthesis method comprising the following steps: Step1: Add a solvent, magnesium chips and an initiator into a reaction flask. The solvent is 2-methyltetrahydrofuran, and the initiator is dibromoethane. Heat to 50-60 °C. Step2: Dropwise add a mixed solution of halogenated benzene and phosphorus trichloride. X in the halogenated benzene is chlorine or bromine, and the molar ratio of halogenated benzene to phosphorus trichloride is 3.0-4.0:

1. After addition, keep the temperature for reaction. The temperature for keeping the temperature is 50-60 °C, and the time for keeping the temperature is 1-2 hours. Step3: After the reaction is completed, cool to room temperature, add water for washing and separate the layers. The organic phase is concentrated to recover the solvent to obtain triphenylphosphine. The synthesis process route diagram is as follows: 。 2. The synthesis method of triphenylphosphine according to claim 1, wherein In S1, the reaction flask is purged with nitrogen before the reaction.

3. The synthesis method of triphenylphosphine according to claim 1, characterized in that, The solvent can also be a single solvent or a mixed solvent of tetrahydrofuran and toluene.

4. The synthesis method of triphenylphosphine according to claim 1, characterized in that, The halogenated benzene and phosphorus trichloride are premixed before dropwise addition.

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