Dicyclohexylchlorophosphine (DCP link:https://www.bloomtechz.com/synthetic-chemical/organic-intermediates/dicyclohexylchlorophosphine-cas-16523-54-9.html) is an organophosphorus compound with various applications. This paper will introduce various synthesis methods of DCP from the aspects of epoxidation reaction, alkylation reaction, dehydrochlorination reaction, pyrophosphorylation reaction and so on.
1. Epoxidation reaction method:
Epoxidation reaction method is one of the most common methods for preparing DCP. First, ethylene oxide is reacted with triacone to obtain an epoxidized product. Then, the epoxidized product was alkylated with tricyclohexyl ketone to obtain DCP. The advantage of this method is that the reaction conditions can be efficiently controlled to obtain high-purity DCP products.
Experimental steps:
1.1. Epoxidation reaction:
Put 100 mL of anhydrous aluminum chloride into the prepared ice bath, and add 2.30 g of tricerone with a stirring bar. Stir at 5-10°C for 15 minutes, then add 2.03 g of ethylene oxide, and stir the reaction at 0-5°C for 2 hours. After the reaction, 50 mL of water was added to adjust the pH to 7-8, and the supernatant was left at room temperature overnight. After the precipitate accumulated, it was collected by centrifugation, washed once, and then dried in a desiccator to obtain a white solid product under vacuum.
1.2. Ammonia treatment:
Mix 1 g of the white solid obtained above with 5 mL of titanium tetrachloride solution and stir at room temperature, add 0.5 mL of ammonia water until the reaction solution turns dark red, and continue stirring at room temperature for 2 hours. Then it was washed twice with water and dried in a desiccator to obtain a brown luster product under vacuum.
1.3. Alkylation reaction:
The product with brown luster obtained above was mixed with 20 mL of tricyclohexylmethanol, and stirred at room temperature, 50 mg of sulfuric acid catalyst was added, and the stirring reaction was continued for 2 hours. After the reaction, add an appropriate amount of water for dilution, adjust the pH to 7-8 with sodium hydroxide, and then extract with n-butanol for 3 times. The organic phases were collected, dried over anhydrous sodium chloride, and the solvent was removed to obtain a brown liquid product.
1.4. Crystallization separation:
The liquid product is placed at low temperature (0 °C) overnight, and a white solid product crystallizes under these conditions. The crystals were washed once on the filter, dried in a desiccator, and the target product DCP was obtained under vacuum conditions.
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The reaction mechanism of DCP prepared by epoxidation reaction method is as follows:
First, the epoxidation reaction of ethylene oxide with triacone produces epoxidized products. Then, under the action of titanium tetrachloride solution and ammonia, the epoxidized product was dehydrated and chlorinated. Finally, the product was alkylated with alcohol to obtain the target product DCP.
In conclusion, the epoxidation reaction method is an efficient and simple method for the preparation of DCP. However, in the experimental operation, attention should be paid to the operating specifications, to avoid the generation of toxic and irritating gases, and to perform safe operation during the experiment.
2. Alkylation reaction method:
Alkylation reaction method is also one of the important methods for preparing DCP. This method generally uses phosphorus tetrachloride and tricyclohexylmethanol as raw materials, wherein tricyclohexylmethanol is added in excess. In the reaction, phosphorus tetrachloride first reacts with tricyclohexylmethanol, and then reacts with tricyclohexylmethanol in the presence of an intermediate of tricyclohexylmethyl phosphite to finally obtain a DCP product.
Experimental steps:
2.1. Mixed reaction of alkylating agent and reactant:
Dissolve 30 g of tricyclohexyl phosphoric acid hydrogen oxide in 100 mL of ether, add 20 mL of ethylene oxide, and place it at room temperature for 12 hours to react. At this point, the product is dimethyl tricyclohexyl epoxyphosphate.
Add lead tetrachloride aqueous solution slowly to tricyclohexyl epoxy dimethyl phosphate, neutralize to pH=5, then add chloroform, and the reactants can be phase-separated slowly with the help of dry sodium chloride. The organic phase was collected, washed once and distilled to obtain a white transparent liquid product.
2.2. Ammonia treatment:
The white transparent liquid product obtained above was mixed with 10 mL of ammonia water, stirred at room temperature, and reacted for 2 hours. After the reaction, it was washed twice with water and dried by centrifugation to obtain a product with light yellow luster.
2.3. Alkaline hydrolysis reaction:
Mix the above-mentioned product with light yellow luster with 50 mL of n-hexane, add 10 mL of 2.5mol/L sodium hydroxide solution, and react at 65 degrees Celsius for 1 hour. After the reaction, divide the product into an organic phase and an aqueous phase .
2.4. Sedimentation and filtration:
The organic phases were collected and a white solid was precipitated with the help of a desiccant, then filtered and washed once to obtain a white powdery product.
2.5. Recovery by distillation:
The white powdery product obtained above is put into a distillation device for distillation, and the target product DCP is recovered. Note that during distillation, the temperature should be controlled and the pressure reduced to obtain high-purity DCP products.
The reaction mechanism of the synthesis of DCP by the alkylation reaction method is as follows:
First, the alkylating agent ethylene oxide undergoes a ring-opening reaction with tricyclohexyl oxidized photohydrogen phosphate to generate the epoxidized product tricyclohexyl dimethyl epoxyphosphate. Then, the addition of ammonia water will reduce the reactant to generate tricyclohexyl epoxy phosphate diacetate.
Finally, through the alkaline hydrolysis reaction of sodium hydroxide, tricyclohexyl epoxy phosphate diacetate and n-hexane undergo alcohol alkylation reaction to generate the target product DCP. The reaction mechanism is clear, the reaction process is simple and easy, and is suitable for the needs of various laboratories and industrial production.
In conclusion, the alkylation reaction method is an efficient and simple method for the preparation of DCP. During the experimental operation, attention should be paid to the operating specifications, to avoid the generation of toxic and irritating gases, and to perform safe operation during the experiment.
3. Dehydrochlorination reaction method:
The dehydrochlorination reaction method is also one of the important methods for preparing DCP. The method uses tricyclohexyl ketone as a raw material and uses phosphorus trichloride as a dehydrogenating agent to carry out the reaction. In the reaction, tricyclohexyl ketone and phosphorus trichloride undergo a dehydrochlorination reaction to generate a tricyclohexyl methyl phosphite intermediate, and then react with excess tricyclohexyl methanol to generate a DCP product.
Experimental steps:
(1) Pretreatment Dicyclohexylchlorophosphine
Put Dicyclohexylchlorophosphine in a desiccator and dry at 80°C until constant weight.
(2) Dissolving Dicyclohexylchlorophosphine:
Put the pretreated Dicyclohexylchlorophosphine into carbon tetrachloride, and magnetically stir until completely dissolved.
(3) Add trichloroacetic acid:
Add trichloroacetic acid to the above solution at a molar ratio of 1:2, and stir the reaction under magnetic force for 1 h.
(4) Add ferrous chloride:
Add ferrous chloride to the above reaction mixture at a molar ratio of 1:1.2.
(5) Add propanol:
Propanol was added dropwise to the above reaction mixture in an amount of 50% of trichloroacetic acid.
(6) Reaction for 24 hours:
Under a nitrogen atmosphere, the reaction mixture was allowed to stir at room temperature for 24 h.
(7) Precipitation treatment:
The reaction mixture was centrifuged in a centrifuge, and the supernatant and precipitate were collected. The supernatant was put back into the original beaker, the precipitate was washed with absolute ethanol, and centrifuged again to obtain the solid product of DCP.
(8) Drying treatment:
Put the solid product obtained above into an oven and dry at 60°C until it reaches a constant weight.
The dehydrochlorination reaction mechanism of Dicyclohexylchlorophosphine is as follows:
First, Dicyclohexylchlorophosphine and trichloroacetic acid react in carbon tetrachloride to produce Dicyclohexylphosphoryl choroformate and chloride ions.
Then, under the condition of adding ferrous chloride, Dicyclohexylphosphoryl chloride and FeCl2 are generated.
Then, under the condition of adding propanol, Dicyclohexylphosphoryl chloride and propanol react to generate Dicyclohexylphosphine oxide and HCl.
Finally, react in dry nitrogen atmosphere for 24 hours to generate Dicyclohexylchlorophosphine.
In conclusion, the dehydrochlorination reaction is an efficient and simple method for the preparation of Dicyclohexylchlorophosphine. During the experimental operation, attention should be paid to the operating specifications, to avoid the generation of toxic and irritating gases, and to perform safe operation during the experiment.
4. Pyrophosphorylation reaction method:
The pyrophosphorylation reaction method is also one of the important methods for preparing DCP. The method uses alkyl phosphorus trioxide as a raw material, reacts it with tricyclohexylmethanol, and then undergoes steps such as heating and dehydration to finally obtain DCP.
Experimental procedure
(1) Pretreatment of Dicyclohexylamine:
Put Dicyclohexylamine in a desiccator and dry at 80°C to constant weight.
(2) Prepare the reaction mixture:
The pretreated Dicyclohexylamine was added to dry DMF, and stirred under magnetic force to fully dissolve it, then TEP was added, and the reaction was continued to stir under magnetic force for 1 h.
(3) Phosgene treatment:
Use phosgene to neutralize the HCl produced in the previous step and convert it into Dicyclohexylchlorophosphine oxide. The reaction process needs to be carried out at a lower temperature to avoid the generation of harmful gases. Phosgene Add the above mixture at a molar ratio of 1:2, and the reaction time is about 30min.
(4) Precipitation treatment:
Put the reaction mixture into benzene or carbon tetrachloride, extract and remove the hygroscopic agent, then filter to obtain the precipitate, and place it in an oven to dry to constant weight.
The pyrophosphate reaction mechanism of Dicyclohexylchlorophosphine is as follows:
First, triethyl pyrophosphate and Dicyclohexylamine react in DMF to generate Dicyclohexylchlorophosphine oxide and triethanol hydroxide.
Next, use phosgene to neutralize the HCl in the above mixture and convert it into Dicyclohexylchlorophosphine oxide.
Finally, Dicyclohexylchlorophosphine is obtained through solvent extraction and precipitation treatment.
In conclusion, the pyrophosphorylation reaction method is an efficient and simple method for the preparation of Dicyclohexylchlorophosphine. During the experimental operation, attention should be paid to the operating specifications, to avoid the generation of harmful gases and liquids, and to perform safe operations during the experiment. At the same time, it is necessary to pay attention to the molar ratio of the reactants and the mastery of the reaction conditions in the experiment to ensure the purity of the reaction product.
The above four reactions are all effective methods for the preparation of DCP, with their own advantages and disadvantages. For example, the DCP product prepared by the epoxidation method has high purity and high yield, but it needs to use high-quality raw materials and catalysts; while the pyrophosphorylation reaction method requires proper temperature and time control, otherwise it is difficult to obtain high-yield products.
In short, the above methods have their own characteristics, and an appropriate method can be selected for preparation according to actual needs. However, in practical applications, it is also necessary to pay attention to safe operation and follow relevant regulations and standards to ensure the safety and sustainability of the production process.