5 results about "Cerium trichloride" patented technology

This invention discloses a depressant-free flotation method for fluorite beneficiation. The method specifically includes the following steps: Step 1: After grinding, the fluorite ore is added to a flotation cell along with an appropriate amount of water. The mixture is stirred and homogenized in the flotation machine to obtain a fluorite slurry. Step 2: A certain amount of collector is added to the fluorite slurry from Step 1, and stirring is continued for 1-5 minutes. Then, a certain amount of frother is added to adjust the slurry. The collector is a BHA-Ce mixture. Step 3: Aeration is performed, and flotation frothing is carried out to obtain fluorite rough concentrate and tailings. This invention uses a mixture of benzoyl hydroxyxamic acid and cerium trichloride as a highly efficient collector for fluorite flotation, directly eliminating the need for depressants. This invention has no special requirements for the flotation environment and can reduce the cost of flotation reagents, subsequent tailings wastewater treatment, and environmental protection.

The application belongs to the technical field of medical organic synthesis, and particularly relates to a preparation method of an oxazole ester compound. The oxazole ester compound is prepared by using N-ethoxyoxalyl-alpha-alanine ethyl ester (oxalate) as a starting material, adding a catalytic amount of rare earth cerium trichloride as a catalyst under the action of triphenylphosphine dichloride and an organic base, and promoting a chloro-cycloaddition reaction by using a rare earth coordination effect. The obtained oxazole ester can be further subjected to saponification and decarboxylation to obtain a vitamin B6 intermediate 4-methyl-5-ethyloxazole. The reaction rate is significantly accelerated and the reaction yield is improved by using the coordination effect of the rare earth cerium trichloride, the amount of the cerium trichloride is as low as 0.003%, and the cerium trichloride is easy to recover. The process does not need to use imidazole compounds as a catalyst, and the problem of difficult recovery of imidazole is avoided. The process is green, environmentally friendly, safe, simple and convenient to operate, the yield and purity of the target product are high, and the process is suitable for industrial production.

The invention provides a preparation method of a key intermediate of a gemfibrozil impurity A, and belongs to the technical field of chemical synthesis. According to the invention, a brand-new synthetic route of the gemfibrozil impurity A is designed firstly, and efficient preparation methods of three key intermediates are provided on the basis of the brand-new synthetic route. Specifically, the preparation method comprises the following steps: firstly, reacting with propionyl chloride in a 1, 2-dichloroethane environment under the catalysis of aluminum trichloride, and cooling, layering and drying a product to obtain a first intermediate; taking the first intermediate as a raw material, reacting with benzyl bromide in a DMF (Dimethyl Formamide) environment by taking potassium carbonate as an acid-binding agent, collecting an organic phase, dissolving with methanol, carrying out reduction reaction by using sodium borohydride under the catalysis of cerium chloride heptahydrate, and collecting to obtain a second intermediate; taking the second intermediate as a raw material, dissolving the second intermediate in methylbenzene, and performing dehydration reaction under the catalysis of TsOH.H2O to obtain a third intermediate; on the basis of the three intermediates, efficient synthesis of the gemfibrozil impurity A can be achieved, the synthesis route is short, and the process efficiency is high.

The invention relates to a synthesis method of (9R, 10S)-2-chloro-9, 10-bis (4-methoxyphenyl)-9, 10-dihydroanthracene-9, 10-diol, and particularly relates to a synthesis method of (9R, 10S)-2-chloro-9, 10-bis (4-methoxyphenyl)-9, 10-dihydroanthracene-9 The synthesis method comprises the following steps: by taking tetrahydrofuran as a solvent, adding cerium trichloride as a catalyst and an exchange system atmosphere as an inert atmosphere, and regulating and controlling a temperature value to activate cerium trichloride so as to obtain cerium trichloride dispersion liquid; under the condition of 10-20 DEG C, adding a Grignard reagent into the cerium trichloride dispersion liquid to be complexed with cerium trichloride to obtain a mixed solution; the Grignard reagent is tetrahydrofuran dispersion liquid of p-methoxyphenyl magnesium bromide; the preparation method comprises the following steps: adding tetrahydrofuran dispersion liquid of 2-chloroanthraquinone into a mixed solution under the condition of 10-20 DEG C, carrying out a reaction, and after the reaction is finished, carrying out quenching and post-treatment to remove impurities, so as to obtain (9R, 10S)-2-chloro-9, 10-bis (4-methoxyphenyl)-9, 10-dihydroanthracene-9, 10-diol, namely (9R, 10S)-2-chloro-9, 10-bis (4-methoxyphenyl)-9, 10-dihydroanthracene-9, 10-diol. According to the synthesis method, raw materials are easy to obtain, and the yield is high and can reach 55% or above.

This invention belongs to the field of organic synthesis technology, specifically relating to a photoelectric synergistic cerium-catalyzed method for the decarboxylation and hydrogenation of aryl carboxylic acids to synthesize aromatic hydrocarbons. The method uses inexpensive, readily available aryl carboxylic acids as substrates, tetraethylammonium chloride or tetrabutylammonium chloride as electrolytes, sodium carbonate, pyridine, 4-dimethylaminopyridine, or bipyridine as inorganic bases, and introduces acetone, butanone, 2-pentanone, or 3-pentanone as hydrogen abstraction donors. Under the catalysis of cerium trichloride heptahydrate or cerium trichloride, the highly active tetravalent cerium-carboxylic acid complex undergoes ligand-metal charge transfer through the synergistic effect of anodic electrooxidation and 395nm~405nm visible light excitation, thus gently removing CO2. This method overcomes the bottleneck of traditional aryl decarboxylation and hydrogenation, which heavily relies on precious metals and high-temperature heating, avoids pollution from equivalent redox reagents, and offers green, mild, and extremely efficient conditions, providing a novel and sustainable strategy for the traceless modification of aryl skeletons.