- Method for preparing diclosan through Baeyer-Villiger oxidation
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The invention provides a method for preparing diclosan by using urea peroxide as an oxidizing agent. Particularly, the method comprises the following steps: (1) oxidizing 5-chloro-2-(4-chloro-phenoxy)-acetophenone in an inert solvent by using urea peroxide as an oxidizing agent to obtain an intermediate I; and (2) hydrolyzing the intermediate I to obtain the diclosan. The method is safe in production process, mild in reaction and suitable for industrial production.
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Paragraph 0010; 0037-0051
(2021/07/01)
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- Preparation method of active bactericide 4,4'-dichloro-2-hydroxyl diphenyl ether
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The invention discloses a preparation method of an active bactericide 4,4'-dichloro-2-hydroxyl diphenyl ether. The preparation method comprises the following steps: preparing phenol metal salts from p-chlorophenol under the effect of an alkali solution; carrying out condensation reactions, nitro reduction reactions, and diazotization hydrolysis reactions between phenol metal salts and 2,5-dichloronitrobenzene; extracting the reaction product by a solvent; and purifying the extract by vacuum distillation to obtain the high quality active bactericide. The operation is convenient, the production cost is low, and the product purity is high. The bactericide can effectively kill or inhibit gram positive bacteria and gram negative bacteria. The bactericide can be easily compounded with a negative ion surfactant, a nonionic surfactant, an amphoteric surfactant, and a positive ion surfactant.
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Paragraph 0032; 0033; 0034; 0037; 0038
(2017/12/09)
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- Process for the preparation of halogenated hydroxydiphenyl compounds
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There is described a process for the preparation of halogenated hydroxydiphenyl compounds of formula (1) by acylation of a halogenated benzene compound (first stage), etherification of the acylated compound with a halogenated phenol compound, which is not further substituted in the ortho-position (second stage), oxidation of the etherified compound (third stage) and hydrolysis of the oxidized compound in a fourth stage, wherein the reaction of the second stage is carried out in the presence of K2CO3 and any desired copper catalyst, where K2CO3 is used in a concentration of from 0.5 to 30 mol, based on the phenol compound employed of formula (6), according to the reaction scheme (I) in which R1 and R2 independently of one another are F, Cl or Br; R3 and R4 independently of one another are hydrogen; or C1-C4alkyl; m is 1 to 3; and n is 1 or 2. The compounds of formula (1) are used for protecting organic materials and articles from microorganisms.
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- Process for the preparation of halogenated hydroxydiphenyl compounds
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A process for the preparation of halohydroxydiphenyl compounds useful for protecting organic materials and articles from microorganisms, of the formula by acylation of a halogenated benzene compound (first stage), etherification of the acylated compound with a halogenated phenol compound (second stage), oxidation of the etherified compound (third stage) and hydrolysis of the oxidized compound in a fourth stage, according to the following reaction scheme: in which R1 and R2 independently of one another are F, Cl or Br; R3 and R4 independently of one another are hydrogen; or C1-C4alkyl; m is 1 to 3; and n is 1 or 2.
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