- PROCESS FOR THE PREPARATION OF 2-CYANOIMIDAZOLE COMPOUNDS
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It is an object of the present invention to provide a novel and advantageous process for commercially preparing of 2-cyanoimidazole compounds. More particularly, it relates to an efficient method of preparation of cyazofamid synthetic precursor by simultaneous conversion of aldoxime group to the corresponding cyano-derivative and reducing of N-oxygenated-imidazole ring to imidazole under mild conditions using reducing agent selected from the group consisting of metal salts of sulfur-containing derivatives in the presence of a polar organic solvent.
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- Synthesis method of cyazofamid
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The invention discloses a synthesis method of cyazofamid. The synthesis method of cyazofamid comprises the following steps: synthesizing 2,2-halogenated-4'-methyl acetophenone; synthesizing 1-hydroxy-4-(4-methyl phenyl)-2-oxime imidazole-3-oxide; synthesizing 2-cyan-4-chlorine-5-(4'-methyl phenyl)imidazole; adding methanol into 1-hydroxy-4-(4-methyl phenyl)-2-oxime imidazole-3-oxide, performing ice-water bath reaction, adding sulfoxide chloride, performing temperature-rising reaction, adding acetonitrile and N-chlorosuccinimide, and performing reaction; and synthesizing cyazofamid: adding 2-cyan-4-chlorine-5-(4'-methyl phenyl)imidazole, anhydrous potassium carbonate, ethyl acetate and N,N-dimethylsulfamoyl chloride into a reaction kettle, and performing refluxing reaction. The synthesis method of cyazofamid has the advantages of rich raw material source, easily available raw materials, low cost, mild reaction condition, no need of special equipment, high economic property, high total yield and good industrialized prospect.
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Paragraph 0015; 0016; 0017
(2018/04/01)
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- A 2 - cyano - 4 - chloro - 5 - (4 - methyl phenyl) imidazole synthesis method
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The invention relates to a synthetic method for 2-cyano-4-chloro-5-(4-methylphenyl)imidazole. The synthetic method comprises the following steps: (1) by taking p-methylacetophenone as a raw material, carrying out a halogenating reaction under a light condition to obtain a compound I; (2) dissolving the obtained compound I in a solvent, stirring the mixture to react at a certain temperature, and performing cooling and suction-filtering to obtain a compound II; (3) dissolving the obtained compound II in a solvent and carrying out a reaction with glyoxal and hydroxylamine sulphate at a certain temperature to obtain a compound III; and (4) dissolving the obtained compound III in a solvent, carrying out a reaction with sulfoxide chloride in an ice bath in a manner of raising the temperature to room temperature and keeping the temperature for the reaction, dropwise adding sulfur chloride, and after reaction, washing the product to obtain a compound IV which is 2-cyano-4-chloro-5-(4-methylphenyl)imidazole. The synthetic method is good in atom economy, simple and convenient in process operation and high in product yield and industrial application value.
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- A 4-chloro-2-cyano-N, N-dimethyl-5 - (4 the [...] -methyl-phenyl) - 1H-imidazole-1-sulfonamide synthesis method
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The invention discloses a synthesis method of 4-chloro-2-cyano-N,N-dimethyl-5-(4-methylphenyl)-1H-imidazole-1-sulfonamide (cyazofamid). According to the synthesis method, methylacetophenone is taken as a raw material, selenium dioxide is used for oxidation to prepare an intermediate, namely 2-carbonyl-2-p-benzyl aldehyde, then N,N-dimethylformamide and the like are taken as solvents, thionyl chloride is taken as a chlorinating agent and reducing agent for preparing the intermediate, and then intermediate further reacts with N,N-dimethyl sulfonamide chloride to synthesize the cyazofamid. Compared with the prior art, the synthesis method has the advantages that the reaction period is shortened, the post-treatment process is simplified and the synthesis method is suitable for mass industrial production.
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Paragraph 0014; 0015
(2017/01/02)
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- 4-chloro-2-cyano-N, N-dimethyl-5-P-tolyl-imidazole-1-sulfonamide synthesis method
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The invention discloses a method for synthesizing 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide. The method is characterized in that 2-carbonyl-2-P-benzyl acetaldehyde is used as a raw material and reacted with glyoxylic acid to synthesize an imidazole ring, and then ammoniation, dehydration, chlorination and sulfonylation are performed, so that 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide is finally synthesized. The purity of 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide prepared by adopting the synthesizing method reaches over 98.0%, and the total yield reaches over 44.5%. The method is cheap and readily available in raw materials, simple, mild in reaction conditions and low in environmental pollution, and produces little wastewater. The method is mainly applied to synthesis of 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide serving as a pesticide bactericide.
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