- Preparation method of carbosulfan
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The invention provides a preparation method of carbosulfan. The method comprises the following steps: (1) dissolving carbosulfan in an organic solvent, adding an acid-binding agent I triethylamine, performing stirring and mixing until uniformity, adding sulfur dichloride in a dropwise manner, and carrying out a thermal insulation reaction after the drop-by-drop addition is finished in order to prepare a sulfide solution; (2) adding di-n-butylamine, 4-dimethylaminopyridine and an acid-binding agent II triethylamine into the obtained sulfide solution, and, carrying out the thermal insulation reaction after the drop-by-drop addition is finished in order to obtain a carbosulfan reaction; and (3) washing the carbosulfan reaction solution until the reaction solution is neutral, separating out the obtained organic phase, and carrying out reduced pressure solvent removal to obtain the carbosulfan with the content of 96% or above, the yield of 98% or above and the harmful impurity carbofuran content of 0.1% or below. The method has the advantages of simplicity in operation, easily available raw materials and low cost, the prepared carbosulfan has the advantages of low content of main harmful impurities, high yield and high purity.
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Paragraph 0040; 0043-0044; 0045; 0048-0049; 0050; 0053-0054
(2020/04/17)
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- Preparation method of carbofuran derivatives
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The invention discloses a preparation method of carbofuran derivatives. The preparation method of the carbofuran derivatives comprises the following steps: (1) taking amine derivatives and sulfur monochloride as raw materials, adding a first acid-binding agent and a reaction solvent and performing sulfuration reaction to obtain a first intermediate disulfide, wherein the first acid-binding agent is triethylamine and the reaction solvent is chloroform or dichloromethane; (2) performing chlorination reaction on the first intermediate disulfide and chlorine which serve as raw materials to obtain a second intermediate nitrogen and sulfur chloride; (3) taking the second intermediate nitrogen and sulfur chloride and carbofuran as raw materials, adding a second acid-binding agent and performing condensation reaction to obtain the carbofuran derivatives. The preparation method has the advantages that the process is simple, and the product is low in toxicity, high in purity and high in yield.
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- SYSTEM FOR PROTECTING GOODS DURING TRANSPORT
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A system for protecting stored goods in a container (10), comprises a cage-like structure (20) formed by at least one pesticide treated net (22), capable of enclosing the stored goods, wherein the cage like structure (20), further comprises means for suspending the pesticide treated nets (14, 28, 30, 32, 34), and means for opening and closing the cage-like structure (26) on at least one section (24) of the at least one net (22). The system is particularly useful for the transport of tobacco, coffee, dried fruits, cocoa, nuts, tea, cereals, vegetables, spices and animals.
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- Trialkylamine/sulfur dioxide catalyzed sulfenylation of carbamates
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An improved process is disclosed for sulfenylating carbamates in the presence of a solvent and acid acceptor, in which the reaction between a carbamate and a sulfenyl halide is conducted in the presence of a catalytic amount of a complex of a lower alkylamine and sulfur dioxide. Several methods for preparing and utilizing the complex in the reaction are disclosed and exemplified.
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- N-aminosulfenylated derivatives of carbofuran
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A new class of chemical compounds useful for the control of insects consists of (methyl)(aminosulfenyl)carbamic acid esters of 2,3-dihydro-2,2-dimethyl-7-benzofuranol. The preparation of these compounds having a variety of (substituted-amino)sulfenyl groups, their physical properties, formulation, and use to control both household insects and crop pests are exemplified.
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