阅读说明：本技术 一种重要的化工原料的制备方法 (Preparation method of important chemical raw material ) 是由 李娟� 于 2021-01-27 设计创作，主要内容包括：本发明提供一种亚磷酸二乙基酯的制备方法,其特征在于,包括以下步骤：室温下,将亚磷酸、银催化剂和水置于反应容器中,搅拌至溶解,然后慢慢往反应容器中滴加乙醇,同时将体系升温至50～100℃,反应1～4h,结束后,停止搅拌,体系静置,收集有机层,减压蒸馏,得到产品。本发明由于采用了可溶性银盐作为催化剂,在水中即可迅速且高效地催化反应,相对于现有技术,反应条件下更加温和,采用水为溶剂更加环保,且由于反应本身有水生成,与反应溶剂一致,反应后使水的含量增加,更加有利于不溶于水的亚磷酸二乙基酯快速地从体系中分离出来,从而使得后处理更加简单高效,既节省反应时间,又提高了产品的收率和纯度。(The invention provides a preparation method of diethyl phosphite, which is characterized by comprising the following steps: and (2) at room temperature, placing phosphorous acid, a silver catalyst and water in a reaction container, stirring until the phosphorous acid, the silver catalyst and the water are dissolved, then slowly dropwise adding ethanol into the reaction container, simultaneously heating the system to 50-100 ℃, reacting for 1-4 h, stopping stirring after the reaction is finished, standing the system, collecting an organic layer, and carrying out reduced pressure distillation to obtain the product. The invention adopts soluble silver salt as catalyst, which can catalyze reaction in water quickly and efficiently, compared with the prior art, the reaction condition is milder, the reaction is more environment-friendly by adopting water as solvent, and the water content is increased after the reaction because the water generated in the reaction is consistent with the reaction solvent, which is more beneficial to quickly separating water-insoluble diethyl phosphite from the system, thereby ensuring that the post-treatment is simpler and more efficient, saving the reaction time and improving the yield and purity of the product.)

1. A method for preparing diethyl phosphite, which is characterized by comprising the following steps: and (2) at room temperature, placing phosphorous acid, a silver catalyst and water in a reaction container, stirring until the phosphorous acid, the silver catalyst and the water are dissolved, then slowly dropwise adding ethanol into the reaction container, simultaneously heating the system to 50-100 ℃, reacting for 1-4 h, stopping stirring after the reaction is finished, standing the system, collecting an organic layer, and carrying out reduced pressure distillation to obtain the product.

2. A process for the preparation of diethyl phosphite according to claim 1, wherein the silver catalyst is selected from silver nitrate or silver acetate.

3. A process for the preparation of diethyl phosphite according to any one of claims 1-2, wherein the silver catalyst is preferably silver nitrate.

4. A method for preparing diethyl phosphite according to any one of claims 1-3, wherein the speed of adding ethanol dropwise is 1-2 mL/min.

5. A process for the preparation of diethyl phosphite according to any one of claims 1-4, wherein the rate of the dropwise addition of ethanol is preferably 1 mL/min.

6. A process according to any one of claims 1 to 5, wherein the molar ratio of the phosphorous acid to the ethanol is from 1:2 to 3.

7. A process for the preparation of diethyl phosphite according to any one of claims 1-6, wherein: the molar ratio of the phosphorous acid to the ethanol is preferably 1: 2-2.5.

8. A process according to any one of claims 1 to 7 for the preparation of diethyl phosphite, wherein: the mass of the silver catalyst to be added per 1mol of phosphorous acid is 1 to 5 g.

9. A process for the preparation of diethyl phosphite according to any one of claims 1-8, wherein: the mass of the silver catalyst to be added per 1mol of phosphorous acid is preferably 1 to 3 g.

10. A process for the preparation of diethyl phosphite according to any one of claims 1-9, wherein: the standing time is 0.5-1 h.

Technical Field

The invention belongs to the field of organic synthesis, and particularly relates to a preparation method of an important chemical raw material, and more particularly relates to a preparation method of diethyl phosphite.

Background

The dialkyl phosphite is an organophosphorus reagent with wide application, and can be used as pesticide, medicine, polymer and organic corrosion inhibition

Agents, flame retardants, and the like. For example, dimethyl phosphite is an important chemical raw material and intermediate, and is widely used in the preparation industries of organic phosphate corrosion inhibitors, synthetic plastic additives, dye additives, combustion improvers and pesticides. The water quality corrosion and scale inhibitor of organic phosphoric acid type and organic phosphonic acid-carboxylic acid type prepared by it is widely used for industrial and chemical circulating water treatment, and various phosphite compounds prepared by it are widely used in plastic industry as phosphorus series auxiliary agents with different functions, additives in dye industry and oil products. Meanwhile, it is also an important intermediate for preparing organophosphorus pesticides such as trichlorphon, dichlorvos, fenoxanil, omethoate, glyphosate and the like.

Diethyl phosphite is also an important organic chemical raw material, is an intermediate for preparing organic phosphorus compounds, is also used as an extractant and an intermediate in phosphate esters, and has very important position in fine chemical engineering. As a raw material of PFA which is a broad-spectrum antiviral drug, and the like. Also used for synthesizing pesticides such as isoprothiolane, aluminum triethyl phosphonate, ethylphosphonium and parathion. It can also be used for synthesizing plasticizer and flame retardant. In addition, the metal corrosion inhibitor can be prepared to be used in coating, is also an important phosphoethylation reagent and is widely used in organic synthesis. Can also be used as a catalyst suitable for various chemical reactions, such as the synthesis of peptide amino acid; has wide application.

At present, the methods for producing dialkyl phosphites are mainly classified into the following methods:

(1) phosphorus trichloride and alcohol are used as reaction raw materials, benzene or xylene and other inert organic solvents are used, and the phosphorus trichloride and the alcohol directly react under the condition of no acid-binding agent or an acid-binding agent, so that the method has the advantages that the reaction does not need a low-temperature environment, the reaction temperature is stable and easy to control, and the yield and the safety are high; but has the disadvantages that the process is more complex, a large amount of HCl gas is generated, a large amount of anticorrosion equipment and energy consumption are needed for carrying out three-waste recovery treatment, and the pollution to the environment is larger.

(2) Phosphorus trichloride and alcohol are used as reaction raw materials, an additional organic solvent is not needed, the phosphorus trichloride and the alcohol are prepared by a liquid phase reaction under negative pressure or a gas phase reaction under pressurization, the advantages are high reaction speed and high product yield, the defects are that a large amount of HCl gas is generated by a complex reaction process, a large amount of anticorrosion equipment and energy consumption are needed for three-waste recovery treatment, and the environmental pollution is large.

(3) The preparation method is characterized in that phosphorous acid and alcohol are directly subjected to esterification reaction, concentrated sulfuric acid is used as a catalyst, toluene is used as a solvent, and water is carried out to obtain corresponding alkyl phosphite. The method has simple reaction and easy operation. The disadvantage is that the yield is not high, only alkyl phosphite containing three or more carbons can be synthesized, and diethyl phosphite cannot be synthesized.

(4) The method is prepared by direct esterification reaction of phosphorous acid and alcohol, hexachlorophosphazene is used as a catalyst, factors such as atmosphere conditions, temperature, concentration, addition of solvent and water, and the dosage of the catalyst are optimized, and the optimal reaction conditions of the reaction are obtained.

Disclosure of Invention

The invention aims to overcome the series of defects existing in the preparation of dialkyl phosphite in the prior art, and provides a preparation method of diethyl phosphite, which is characterized by comprising the following steps: and (2) at room temperature, placing phosphorous acid, a silver catalyst and water in a reaction container, stirring until the phosphorous acid, the silver catalyst and the water are dissolved, then slowly dropwise adding ethanol into the reaction container, simultaneously heating the system to 50-100 ℃, reacting for 1-4 h, stopping stirring after the reaction is finished, standing the system, collecting an organic layer, and carrying out reduced pressure distillation to obtain the product.

According to the preparation method of diethyl phosphite, the silver catalyst is selected from silver nitrate or silver acetate.

According to the preparation method of diethyl phosphite, the silver catalyst is preferably silver nitrate.

According to the preparation method of diethyl phosphite, the speed of dripping ethanol is 1-2 mL/min.

According to the preparation method of diethyl phosphite, the speed of dripping ethanol is preferably 1 mL/min.

The preparation method of diethyl phosphite is characterized in that the molar ratio of phosphorous acid to ethanol is 1: 2-3.

The preparation method of diethyl phosphite according to the invention is characterized in that: the molar ratio of the phosphorous acid to the ethanol is preferably 1: 2-2.5.

The preparation method of diethyl phosphite according to the invention is characterized in that: the mass of the silver catalyst to be added per 1mol of phosphorous acid is 1 to 5 g.

The preparation method of diethyl phosphite according to the invention is characterized in that: the mass of the silver catalyst to be added per 1mol of phosphorous acid is preferably 1 to 3 g.

The process according to the present invention for preparing diethyl phosphite, wherein: the standing time is 0.5-1 h.

The process according to the present invention for preparing diethyl phosphite, wherein: the time for the standing is preferably 0.5 h.

The main contributions of the present invention with respect to the prior art are the following:

(1) the invention takes phosphorous acid and ethanol as reaction substrates, soluble silver salt as a catalyst and water as a solvent for reaction, and the method adopts the soluble silver salt as the catalyst, so that the reaction can be rapidly and efficiently catalyzed in water.

(2) The catalyst used in the method is simple and easy to obtain, low in price and good in catalytic activity, and can obtain satisfactory yield and yield under the condition of using a small amount of catalyst, and compared with other prior art, the method has the unexpected technical effect.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure are clearly and completely described. It is to be understood that the described embodiments are only a few embodiments of the present disclosure, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

The preparation method of diethyl phosphite is characterized by comprising the following steps: and (2) at room temperature, placing phosphorous acid, a silver catalyst and water in a reaction container, stirring until the phosphorous acid, the silver catalyst and the water are dissolved, then slowly dropwise adding ethanol into the reaction container, simultaneously heating the system to 50-100 ℃, reacting for 1-4 h, stopping stirring after the reaction is finished, standing the system, collecting an organic layer, and carrying out reduced pressure distillation to obtain the product.

According to the preparation method of diethyl phosphite, the silver catalyst is selected from silver nitrate or silver acetate.

According to the preparation method of diethyl phosphite, the silver catalyst is preferably silver nitrate.

According to the preparation method of diethyl phosphite, the speed of dripping ethanol is 1-2 mL/min.

According to the preparation method of diethyl phosphite, the speed of dripping ethanol is preferably 1 mL/min.

The preparation method of diethyl phosphite is characterized in that the molar ratio of phosphorous acid to ethanol is 1: 2-3.

The preparation method of diethyl phosphite according to the invention is characterized in that: the molar ratio of the phosphorous acid to the ethanol is preferably 1: 2-2.5.

The preparation method of diethyl phosphite according to the invention is characterized in that: the mass of the silver catalyst to be added per 1mol of phosphorous acid is 1 to 5 g.

The preparation method of diethyl phosphite according to the invention is characterized in that: the mass of the silver catalyst to be added per 1mol of phosphorous acid is preferably 1 to 3 g.

The process according to the present invention for preparing diethyl phosphite, wherein: the standing time is 0.5-1 h.

The process according to the present invention for preparing diethyl phosphite, wherein: the time for the standing is preferably 0.5 h.

Example 1

At room temperature, 0.1mol of phosphorous acid, 0.1g of silver nitrate and 30mL of water are placed in a reaction container and stirred until the phosphorous acid, the silver nitrate and the water are dissolved, then 0.25mol of ethanol is slowly dripped into the reaction container at the dripping speed of 1mL/min, simultaneously, the system is heated to 50 ℃ and reacts for 4 hours, after the reaction is finished, the stirring is stopped, the system is kept still for 1 hour, an organic layer is collected and is subjected to reduced pressure distillation to obtain a product diethyl phosphite, and the yield is 94.0% and the purity is 96.8% by calculation.

Example 2

At room temperature, 0.1mol of phosphorous acid, 0.3g of silver nitrate and 30mL of water are placed in a reaction container and stirred until the phosphorous acid, the silver nitrate and the water are dissolved, then 0.25mol of ethanol is slowly dropped into the reaction container, the dropping speed is 1mL/min, simultaneously, the system is heated to 80 ℃, the reaction is carried out for 2 hours, after the reaction is finished, the stirring is stopped, the system is kept still for 0.5 hour, an organic layer is collected, reduced pressure distillation is carried out, and a product diethyl phosphite is obtained, wherein the yield is 94.7% and the purity is 98.8% through calculation.

Example 3

At room temperature, 0.1mol of phosphorous acid, 0.3g of silver nitrate and 30mL of water are placed in a reaction container and stirred until the phosphorous acid, the silver nitrate and the water are dissolved, then 0.3mol of ethanol is slowly dropped into the reaction container, the dropping speed is 2mL/min, simultaneously, the system is heated to 50 ℃, the reaction is carried out for 4 hours, after the reaction is finished, the stirring is stopped, the system is kept still for 0.5 hour, an organic layer is collected, reduced pressure distillation is carried out, and a product diethyl phosphite is obtained, wherein the yield is 93.9% and the purity is 96.7% by calculation.

Example 4

At room temperature, 0.1mol of phosphorous acid, 0.5g of silver nitrate and 30mL of water are placed in a reaction container and stirred until the phosphorous acid, the silver nitrate and the water are dissolved, then 0.2mol of ethanol is slowly dropped into the reaction container, the dropping speed is 1mL/min, simultaneously, the system is heated to 100 ℃, the reaction is carried out for 2 hours, after the reaction is finished, the stirring is stopped, the system is kept still for 0.5 hour, an organic layer is collected, reduced pressure distillation is carried out, and a product diethyl phosphite is obtained, wherein the yield is 92.9% and the purity is 97.5% through calculation.

Example 5

At room temperature, 0.1mol of phosphorous acid, 0.1g of silver acetate and 30mL of water are placed in a reaction container and stirred until the phosphorous acid, the 0.25mol of ethanol are slowly dropped into the reaction container at the dropping speed of 1mL/min, meanwhile, the system is heated to 80 ℃ and reacts for 2 hours, after the reaction is finished, the stirring is stopped, the system is kept still for 0.5 hour, an organic layer is collected, reduced pressure distillation is carried out, and a product diethyl phosphite is obtained, wherein the yield is 91.0% and the purity is 95.7%.

Example 6

At room temperature, 0.1mol of phosphorous acid, 0.3g of silver acetate and 30mL of water are placed in a reaction container and stirred until the phosphorous acid, the 0.2mol of ethanol are slowly dropped into the reaction container at the dropping speed of 1mL/min, meanwhile, the system is heated to 50 ℃ and reacts for 4 hours, after the reaction is finished, the stirring is stopped, the system is kept still for 0.5 hour, an organic layer is collected, reduced pressure distillation is carried out, and a product diethyl phosphite is obtained, wherein the yield is 91.5% and the purity is 96.3%.

Example 7

At room temperature, 0.1mol of phosphorous acid, 0.5g of silver acetate and 30mL of water are placed in a reaction container and stirred until the phosphorous acid, the 0.3mol of ethanol are slowly dropped into the reaction container at the dropping speed of 2mL/min, meanwhile, the system is heated to 100 ℃ and reacts for 1h, after the reaction is finished, the stirring is stopped, the system is kept still for 1h, an organic layer is collected and is subjected to reduced pressure distillation, and a product diethyl phosphite is obtained, wherein the yield is 90.8% and the purity is 95.9%.

Example 8

At room temperature, 0.1mol of phosphorous acid, 0.2g of silver acetate and 30mL of water are placed in a reaction container and stirred until the phosphorous acid, the 0.3mol of ethanol are slowly dropped into the reaction container at the dropping speed of 1mL/min, meanwhile, the system is heated to 80 ℃ to react for 1h, after the reaction is finished, the stirring is stopped, the system is kept still for 1h, an organic layer is collected and is subjected to reduced pressure distillation to obtain a product diethyl phosphite, and the yield is 90.6% and the purity is 96.5% by calculation.

Finally, it should be noted that: it should be understood that the above examples are only for clearly illustrating the present invention and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.