- Preparation method and applications of azimsulfuron key intermediate
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The present invention provides a preparation method of 1-methyl-4-(2-methyl-2H-tetrazole-5-yl)1H-pyrazole-5-sulfamide. The preparation method comprises that trimethyl orthoformate and malononitrile are adopted as starting raw materials, a three-step reaction is performed to obtain 1-methyl-5-amino-4-(tetrazole-5-yl)pyrazole, the 1-methyl-5-amino-4-(tetrazole-5-yl)pyrazole reacts with dimethylsulfate in the presence of an acid-binding agent to obtain 2-methyl-5-(1-methyl-5-amino-1H-pyrazole-4-yl)-2H-tetrazole, the 2-methyl-5-(1-methyl-5-amino-1H-pyrazole-4-yl)-2H-tetrazole is subjected to a sodium nitrite diazo-reaction under an acid condition, the obtained material reacts with a sodium sulfite-copper chloride-acetic acid mixture, and finally hydrolysis with ammonia is performed to obtain the target product. The present invention further provides a preparation method of azimsulfuron prepared from the 1-methyl-4-(2-methyl-2H-tetrazole-5-yl)1H-pyrazole-5-sulfamide. The preparation method of the present invention has characteristics of short reaction route, environmental protection raw materials, and high yield.
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- PROCESS OF PREPARATION OF AZIMSULFURON
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The present disclosure provides process for preparation of azimsulfuron or its salts, isomers, and other derivatives thereof. The process involves treating a compound of formula I, with aqueous acetic acid or formic acid and chlorine gas or sodium hypochlorite in presence of hydrochloric acid in chlorinated solvents such as dichloromethane, 1,2-dichloroethane or with aqueous acetic acid and N-chlorosuccinimide or hydrogen peroxide in presence of hydrochloric acid in aqueous cyclic ether such as tetrahydrofuran, 1,4-dioxane to obtain 1-methyl-4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazole-5-sulfonyl chloride; converting the sulfonyl chloride to a sulfonamide and treating the sulfonamide with a phenyl(4,6-dimethoxypyrimidin-2-yl) carbamate to obtain azimsulfuron or its salts, isomers, and other derivatives thereof.
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- PROCESS OF PREPARATION OF AZIMSULFURON
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The present disclosure provides process for preparation of azimsulfuron or its salts, isomers, and other derivatives thereof. The process involves treating a compound of formula I, (Formula I should be inserted here.) with aqueous acetic acid or formic acid and chlorine gas or sodium hypochlorite in presence of hydrochloric acid in chlorinated solvents such as dichloromethane, 1,2-dichloroethane or with aqueous acetic acid and N-chlorosuccinimide or hydrogen peroxide in presence of hydrochloric acid in aqueous cyclic ether such as tetrahydrofuran, 1,4-dioxane to obtain 1-methyl-4-(2-methyl-2H-tetrazol-5-yl)-1H-pyrazole-5-sulfonyl chloride; converting the sulfonyl chloride to a sulfonamide and treating the sulfonamide with a phenyl(4,6-dimethoxypyrimidin-2-yl) carbamate to obtain azimsulfuron or its salts, isomers, and other derivatives thereof.
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