- Preparation method of 4-halogenated-3-fluorotoluene
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The invention belongs to the field of organic synthesis, and particularly relates to a preparation method of 4-halogenated -3-fluorotoluene. The preparation reaction of 4-halogenated -3-fluorotolueneshown as a formula (I) is shown in the specification. According to the method, halogenation reaction is conducted on 3-fluorotoluene serving as an initial raw material to obtain a halide, and hydrogenreduction is conducted to obtain a compound shown in the general formula (I), wherein X is chlorine or bromine. According to the method, 3-fluorotoluene is used as a raw material, and a target product is obtained through two-step reactions of halogenation and reduction. The reaction steps in the process are few; diazotization, nitrification and other reactions are avoided, and the reaction safetyis high.
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Paragraph 0065; 0067
(2021/03/31)
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- Two-step regioselective synthesis of 1,2-difluorobenzenes from chlorotrifluoroethylene and buta-l,3-dienes
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The gas-phase copyrolysis of chlorotrifluoroethylene with buta-1,3-diene, penta-1,3-diene, or isoprene in a flow reactor at 440–480°C gave 4-chloro-4,5,5-trifluorocyclohex-1-enes. The latter treated with aqueous KOH under condition of phase-transfer catalysis were selectively converted into 1,2-difluorobenzene, 2,3-difluorotoluene, or 3,4-difluorotoluene.
- Lipkind, M. B.,Nefedov, O. M.,Volchkov, N. V.
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- Continuous production method for industrially preparing 2,3-difluorobenzotrifluoride and 3,4-difluorobenzonitrile
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The invention discloses a continuous production method for industrially preparing 2,3-difluorobenzotrifluoride and 3,4-difluorobenzonitrile. The preparation process of the 2,3-difluorobenzotrifluoride comprises the preparation step of an intermediate raw material for benzene sulfonamide and benzenesulfonylurea herbicides, and the preparation process of the 3,4-difluorobenzonitrile comprises the preparation step of a cthalofop-butyl intermediate raw material. The method is suitable for industrial production; and compared with the prior art, the method has the advantages of low cost, high production method and less pollution.
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Paragraph 0027
(2018/03/24)
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- A 2-chloro-6-fluoro anisole and wherein the intermediate preparation method
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The invention discloses a method for preparing 2-chlorine-6-fluoroanisole and midbodies of the 2-chlorine-6-fluoroanisole. The method for preparing the 2-chlorine-6-fluoroanisole comprises the following step that under the condition that the temperature ranges from 100 DEG C to 150 DEG C, a cleavage reaction is conducted on a compound shown as the formula V. A method for preparing a compound shown as the formula III comprises the following step that in a solvent and under catalysis of platinum carbon, a reduction reaction is conducted on a compound shown as the formula II and hydrogen, so that the compound shown as the formula III is obtained. A method for preparing the compound shown as the formula II comprises the following step that in a solvent and under catalysis of a catalyst, an etherification reaction is conducted on a compound shown as the formula I and sodium methylate, so that the compound shown as the formula II is obtained. According to the method for preparing the 2-chlorine-6-fluoroanisole, raw materials are low in price and easy to obtain, the production cost is low, reaction conditions are gentle, the yield is high, and the method is suitable for industrialized production.
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Paragraph 0043; 0044; 0051; 0052; 0053; 0054; 0055
(2017/02/23)
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