A method for preparing palladium dichloride (di(cyanobenzene))
By employing low-temperature grinding and vacuum drying methods, the problems of high energy consumption, significant safety hazards, and low purity in the preparation process of palladium dichloride (cyanobenzene) were solved, thus enabling the preparation of high-purity products.
Patent Information
- Application Number
- CN202610449618.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-07
- Publication Date
- 2026-05-26
AI Technical Summary
Existing methods for preparing palladium dichloride (di(cyanobenzene)) have problems such as high energy consumption, significant safety hazards, high environmental pressure, and low product purity.
A low-temperature grinding and vacuum drying method was adopted. Benzonitrile and palladium chloride were mixed in an appropriate ratio at room temperature and then ground, followed by vacuum drying to avoid high-temperature side reactions and ensure complete conversion of solid raw materials.
A low-cost, safe, and environmentally friendly method for preparing high-purity palladium dichloride (di(cyanobenzene)) with a purity exceeding 99.9% has been achieved, solving the problem of side reaction impurities at high temperatures.
Abstract
Description
Technical Field
[0001] This invention relates to the field of preparation technology of di(cyanobenzene)palladium dichloride, specifically to a method for preparing di(cyanobenzene)palladium dichloride. Background Technology
[0002] Di(cyanobenzene)palladium dichloride, also known as bis(benzonitrile)palladium chloride or trans-bis(benzylnitrile)palladium(II) chloride, has the chemical formula C14H10Cl2N2Pd and a molecular weight of 383.57. It is a yellow powder, insoluble in water but soluble in acetone and chloroform. Di(cyanobenzene)palladium dichloride is an organometallic catalyst. Its molecular structure centers on palladium, a transition metal with excellent catalytic activity, surrounded by chloride ions and phenylacetonitrile molecules. Phenylacetonitrile itself is an organic compound containing a benzene ring and a nitrile group (-CN), which provides stability and allows it to participate in electron transfer processes during reactions. The main value of di(cyanobenzene)palladium dichloride lies in catalysis. It is used as a catalyst in organic synthesis, especially in cross-coupling reactions such as the Suzuki or Heck reactions. These reactions are important means of constructing carbon-carbon bonds and are widely used in the production of pharmaceutical intermediates, materials science, fine chemicals, pharmaceutical chemicals, and liquid crystal materials.
[0003] The conventional method for preparing palladium chloride from benzonitrile involves suspending palladium chloride in a large quantity of benzonitrile, with a mL / g ratio of benzonitrile to palladium chloride exceeding 100. Benzonitrile serves as both a raw material and a solvent. Incomplete reactions occur due to solid agglomeration, necessitating reflux heating to improve the conversion rate of the raw material solids. Reflux heating, at extremely high temperatures approaching 200 degrees Celsius, not only consumes a large amount of energy and places high demands on equipment but also poses significant safety hazards to operators. The solvent recovery process results in substantial losses of benzonitrile, leading to high costs and significant environmental impact. Furthermore, the high reaction temperature and long reaction time generate a large amount of black impurities, affecting product purity.
[0004] Therefore, through in-depth research and technological improvements, we have obtained a method for preparing palladium dichloride (di(cyanobenzene)dichloride) that is economical, safe, environmentally stress-free, and can produce high-purity products with a purity exceeding 99.9%. Summary of the Invention
[0005] To overcome the shortcomings of current popular manufacturing methods, this invention provides a technical improvement scheme for producing palladium dichloride (di(cyanobenzene)dichloride) with a purity exceeding 99.9%, which is economical, safe, environmentally stress-free, and yields high-purity products.
[0006] A method for preparing palladium dichloride (di(cyanobenzene)) includes the following steps:
[0007] Benzonitrile and palladium chloride are mixed in a certain proportion and then ground in a grinding device. After grinding, the mixture is dried to obtain high-purity benzonitrile palladium chloride.
[0008] In some studies, benzonitrile and palladium chloride were mixed at a ratio of 3.5 to 5 ml / g.
[0009] In some research examples, the grinding equipment includes a stone roller coated with smooth polytetrafluoroethylene and a flat-bottomed kettle coated with polytetrafluoroethylene.
[0010] In some studies, the grinding time was 20 to 30 minutes.
[0011] In some studies, grinding was performed at room temperature.
[0012] In some research cases, the reaction ended without side reactions due to the low reaction temperature, and the solid raw materials could achieve 100% conversion, allowing them to be directly dried by vacuum drying.
[0013] This invention uses benzonitrile and palladium chloride as raw materials, mixed in a suitable and economical ratio, and then ground in a grinding device at room temperature and low temperature. Because there are no side reactions, the solid raw materials are completely converted, and the product can be directly obtained by vacuum drying. The amount of liquid raw materials is significantly reduced from a ratio coefficient exceeding 100 to 3.5-5, and the reaction temperature is lowered from nearly 200 degrees Celsius to room temperature, solving the problem of side reactions and impurities generated at high temperatures. This invention can prepare impurity-free palladium di(cyanobenzene) chloride with a purity exceeding 99.9% using a method that requires low energy consumption, low cost, low operating conditions, and low environmental pressure. Detailed Implementation
[0014] The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0015] Example 1
[0016] A method for preparing palladium dichloride (di(cyanobenzene)) includes the following steps:
[0017] Benzonitrile and palladium chloride were separately placed in a PTFE-coated flat-bottomed reactor at a ratio of 4 mL to 4 g. The mixture was ground using a PTFE-coated grinding stone at 25°C for 15 minutes. After grinding, the mixture was dried under vacuum, yielding a powder containing brownish-red particles. Analysis revealed that the brownish-red particles were unreacted palladium chloride. The grinding time was insufficient.
[0018] Example 2
[0019] Benzonitrile and palladium chloride were placed separately into a flat-bottomed reactor coated with polytetrafluoroethylene (PTFE) at a ratio of 4 mL to 4 g. The mixtures were then ground using a smooth PTFE-coated stone roller at 25°C for 30 minutes. After grinding, the mixtures were dried under vacuum. The resulting product had a purity of 99.9% and a yield of 99.3%.
[0020] Example 3
[0021] Benzonitrile and palladium chloride were separately placed in a PTFE-coated flat-bottomed autoclave at a ratio of 4 mL to 4 g. The mixtures were ground using a PTFE-coated grinding stone at 25°C for 50 minutes. After grinding, the mixtures were dried under vacuum. The resulting product had a purity of 99.9% and a yield of 99.2%. Extending the grinding time did not positively affect the product yield.
[0022] Example 4
[0023] Benzonitrile and palladium chloride were reacted at a ratio of 4 mL to 4 g. The benzonitrile was heated to 50°C and then placed separately into a flat-bottomed reactor coated with polytetrafluoroethylene (PTFE). The mixture was ground using a smooth PTFE-coated stone roller at 50°C for 50 minutes. After grinding, the mixture was dried under vacuum. The resulting product had a purity of 99.3% and a yield of 98.8%. This indicates that increasing the reaction temperature from 25°C to 50°C initiated side reactions.
[0024] Example 5
[0025] Benzonitrile and palladium chloride were separately placed in a PTFE-coated flat-bottomed reactor at a mL / g ratio of 3.5. The mixtures were ground using a PTFE-coated grinding stone at 25°C for 30 minutes. After grinding, the mixtures were dried under vacuum. The product obtained had a purity of 89.5% and a yield of 95.2%. Insufficient benzonitrile resulted in incomplete reaction.
[0026] Example 6
[0027] Benzonitrile and palladium chloride were separately placed in a PTFE-coated flat-bottomed reactor at a mL / g ratio of 3.5. The mixtures were ground using a PTFE-coated grinding stone at 25°C for 50 minutes. After grinding, the mixtures were dried under vacuum. The resulting product had a purity of 89.1% and a yield of 94.8%. This indicates that insufficient benzonitrile led to incomplete reaction. Even extending the grinding time did not positively affect the product yield when benzonitrile was insufficient.
[0028] Example 7
[0029] Benzonitrile and palladium chloride were separately placed in a PTFE-coated flat-bottomed reactor at a mL / g ratio of 4. The mixtures were ground using a PTFE-coated grinding stone at 0°C for 30 minutes. After grinding, the mixtures were dried under vacuum. The resulting product had a purity of 92.9% and a yield of 102.6%. Analysis revealed that the product contained 3% water and 3.6% palladium chloride, indicating that the low temperature (0°C) was detrimental to complete the reaction, as the low temperature allowed the product system to absorb moisture from the environment.
[0030] Example 8
[0031] Benzonitrile and palladium chloride were placed separately in a PTFE-coated flat-bottomed reactor at a mL-to-glycine ratio of 4. The mixtures were ground using a PTFE-coated grinding stone at 25°C for 20 minutes. After grinding, the mixtures were dried under vacuum. The resulting product had a purity of 96.9% and a yield of 97.3%. Analysis revealed the presence of unreacted palladium chloride in the system.
[0032] Comparative Example 1
[0033] Palladium chloride (50 g) was dissolved in 5000 mL of benzonitrile, and the mixture was stirred magnetically at 160°C for 1 hour, followed by rapid filtration. Residual benzonitrile was washed with petroleum ether, and the product was dried to obtain the target product. Analysis showed that the target product contained 2.8% residual palladium chloride, with a product purity of 93.3%.
[0034] Comparative Example 2
[0035] 50 g of palladium chloride was dissolved in 5000 mL of benzonitrile, and the mixture was stirred magnetically at 160°C for 1 hour, followed by rapid filtration. Residual benzonitrile was washed with petroleum ether, and the product was dried to obtain the target product. Analysis showed that the target product contained 2.5% residual palladium chloride, with a purity of 89.6%. This indicates that extending the reaction time at high temperature actually increased side reactions and reduced product purity.
[0036] Comparative Example 3
[0037] Palladium chloride (50 g) was dissolved in 5000 mL of benzonitrile, and the mixture was stirred magnetically at 90°C for 3 hours, followed by rapid filtration. Residual benzonitrile was washed with petroleum ether, and the product was dried to obtain the target product. Analysis showed that the target product contained 26.9% residual palladium chloride, with a product purity of 71.7%. This indicates that lowering the temperature would prevent a significant amount of palladium chloride from reacting completely.
[0038] Conclusions or experimental data explanation: Based on the data from the examples and comparative examples, it can be seen that when benzonitrile and palladium chloride are mixed in a suitable and economical ratio and ground in a grinding device at room temperature and low temperature, the solid raw materials are completely converted without side reactions, and the product can be directly obtained by vacuum drying. Because the proportion of liquid raw materials is greatly reduced from over 100 to 3.5-5, and the reaction temperature is lowered from nearly 200 degrees Celsius to room temperature, the problem of side reaction impurities generated at high temperatures is solved.
[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0040] 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.
[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing palladium dichloride (di(cyanobenzene)), characterized in that, Includes the following steps: S1: Ingredients Benzonitrile and palladium chloride were mixed in a specific ratio to form a mixture. S2: Grinding Benzonitrile and palladium chloride were mixed and then ground in a grinding device. S3: Drying After grinding, the mixture is dried to obtain high-purity benzonitrile palladium chloride.
2. The method for preparing palladium di(cyanobenzene) chloride according to claim 1, characterized in that: In step S1, benzonitrile and palladium chloride are mixed at a ratio of 3.5 to 5 ml / gram.
3. The method for preparing palladium di(cyanobenzene) chloride according to claim 1, characterized in that: The grinding equipment used in step S2 includes a stone roller coated with smooth polytetrafluoroethylene and a flat-bottomed kettle coated with polytetrafluoroethylene.
4. The method for preparing palladium di(cyanobenzene) chloride according to claim 1, characterized in that: The grinding time in step S2 is 20 to 30 minutes.
5. The method for preparing palladium dichloride (di(cyanobenzene)) according to claim 1, characterized in that: In step S2, the grinding process is carried out at a room temperature of 25°C.
6. The method for preparing palladium dichloride (di(cyanobenzene)) according to claim 1, characterized in that: In step S3, the mixture is dried by vacuum drying.