- Synthesis method of 2-bromo-5-fluorobenzotrifluoride
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The invention relates to a synthesis method of 2-bromo-5-fluorobenzotrifluoride. The synthesis method comprises the following steps: with benzotrifluoride as a raw material, mixing benzotrifluoride with sulfuric acid, potassium bromide, cuprous bromide and a catalyst, and carrying out a bromination reaction to obtain 2-bromobenzotrifluoride; putting the obtained 2-bromobenzotrifluoride into a DMSOsolvent, adding potassium fluoride and KCoF4, and carrying out a fluorination reaction so as to obtain 2-bromo-5-fluorobenzotrifluoride. According to the method, trifluorotoluene is used as the raw material; the method is a brand-new synthetic route; bromination and fluorination conditions are mild; reaction yield is high; used raw materials are easy to purchase and low in price; and thus, the method has relatively high industrial application value.
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Paragraph 0025; 0027-0028; 0030-0031; 0033-0034; 0036-0037
(2020/07/15)
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- A process for preparing 2 - bromo - 5 - fluoro-toluene method
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The invention discloses a method for preparing 2-bromine-5-fluorobenzotrifluoride. According to the preparation method, fluorobenzotrifluoride serves as a raw material, under the condition of concentrated sulfuric acid and composite catalysts, bromine is stirred and added dropwise, and 2-bromine-5-fluorobenzotrifluoride is obtained after separation and purification. The yield reaches over 91.1%, the reaction conversion rate is larger than 99%, and selectivity is 92-95%. The raw material applied in the reaction process is convenient to purchase, production cost is low, waste acid obtained in the reaction process can be recycled, post-processing is easy, and the whole technology does not generate a large amount of wastewater containing salt and organic matter. Economic benefits and social benefits are good.
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Paragraph 0023; 0024; 0025; 0026; 0027; 0028
(2017/08/25)
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- Normal-temperature catalyzed synthesis of 2-bromo-5-fluorobenzotrifluoride
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The invention discloses a method for preparing 2-bromo-5-fluorobenzotrifluoride. In the method, fluorobenzotrifluoride is used as a raw material, bromine is used as a brominating agent, and the 2-bromo-5-fluorobenzotrifluoride is synthesized in the presence of sulfuric acid and a composite catalyst at normal temperature. By means of the method, the yield reaches 90.0% or above, the purity reaches 99.0% or above, the raw materials used in the reaction process are convenient to purchase, the production cost is low, the waste acid obtained in the reaction process can be recycled, the post-treatment is easy, the reaction conditions are mild, and the method has good economic benefits and social benefits.
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Paragraph 0028; 0029; 0030; 0031; 0032; 0033; 0034-0043
(2017/12/04)
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- Synthesis method of 2-bromo-5-fluorobenzotrifluoride
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The invention relates to a synthesis method of 2-bromo-5-fluorobenzotrifluoride, belonging to the field of chemical synthesis. The method uses orthotrifluoromethyl aniline as the initial raw material, and comprises the following steps: (1) Sandmeyer bromination reaction; (2) nitration reaction; (3) catalytic hydrogenation reduction reaction; and (4) diazotization fluorination reaction. According to the method, the orthotrifluoromethyl aniline used as the raw material is subjected to Sandmeyer reaction bromination, nitration, hydrogenation reduction and diazotization fluorination to finally synthesize the 2-bromo-5-fluorobenzotrifluoride. The 2-bromo-5-fluorobenzotrifluoride product has the advantages of high purity (up to 99.0% or above), fewer impurity varieties and stable quality and properties.
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- 2-bromo-5- fluorine three fluorine methylbenzene preparation method
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The invention discloses a method for preparing 2-bromine-5-trifluorotoluene chloride. The method comprises the following step: under an anhydrous condition and in an organic solvent, performing cracking reaction on an anhydrous compound 1 or a compound 1', thereby preparing 2-bromine-5-trifluorotoluene chloride. According to the method, the reaction of an upper amino protecting group of m-trifluoromethyl phenylamine, the bromination reaction and the reaction of removing the amino protecting group can be all performed in one same reaction kettle without transferring or storing materials. The raw materials used in the method disclosed by the invention are cheap and easy to obtain, the reaction step is short, the reaction condition is gentle, the utilization rate of bromine is high, and the positioning selectivity of bromine feeding is high, so that a final product is low in isomeride impurity, high in reaction conversion rate, high in yield, high in product purity, low in production cost is low and applicable to industrialization production. The compound 1 and compound 1' are as shown in the specification.
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- PROCESS FOR THE PREPARATION OF SUBSTITUTED BENZOTRIHALIDE
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The present invention provides a process for the preparation of compound of Formula I; wherein X is selected from the group consisting of fluorine, chlorine, bromine and iodine; Y is selected from X and -NR1R2; R1 and R1, independent of each other, are selected from the group consisting of hydrogen, C1-4 alkyl and –COR; R is C1-4 alkyl.
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Page/Page column 9
(2016/06/06)
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