Imidaclothiz synthesis method

Abstract

The invention relates to an imidaclothiz synthesis method. The imidaclothiz synthesis method comprises steps as follows: (1), nitroguanidine with water content being 50% and sulfuric acid with mass concentration being 70% are added to a reaction kettle A, ethanediamine is dropwise added, the temperature is increased to 80-90 DEG C for a reaction, a product is filtered, washed and dried after the reaction, and an intermediate alkylimidazole is obtained; (2), toluene, alkylimidazole, potassium carbonate and tetrabutylammonium bromide are sequentially added to a reaction kettle B, a mixed solution is formed, a toluene solution with dissolved 2-chloro-5-chloromethylthiazole is dropwise added, a heating reaction is performed at the temperature of 45-49 DEG C for 6-8 h, finally, the solution is left to stand for layering, and yellow solid imidaclothiz is obtained through desolventizing. The imidaclothiz synthesis method has the advantages that side reactions are controlled by dropwise adding ethanediamine in an alkylimidazole generating process, meanwhile, the consumption ratio of the raw materials in the reactions is controlled strictly, so that the yield and the content of the imidaclothiz product can be greatly increased, the yield can be increased to 90% or higher, and the content of the imidaclothiz product can be increased to 95% or higher.

Description

technical field [0001] The invention belongs to the technical field of insecticide preparation, in particular to a synthesis method of chlorothialine. Background technique [0002] Chlorthialine is a systemic insecticide that acts on nicotinic acetylcholinesterase receptors, and has a blocking effect on the conduction of synaptic nerves in pests. Chlorothialine has the characteristics of broad spectrum, high efficiency, low toxicity, low residue, no resistance to pests, and is safe to humans, animals, plants and natural enemies. [0003] At present, the following method is generally adopted to synthesize chlorothiline, 2-chloro-5-chloromethylthiazole and 2-nitroiminoimidazolidine, in the reaction solvent, under the action of a catalyst, an electrophilic substitution reaction occurs, and the hydrogen chloride produced Adopt acid-binding agent to neutralize and condense to obtain chlorothialine product; Reaction equation: During the condensation reaction, if there is an exc...

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Problems solved by technology

[0003] At present, the following method is generally adopted to synthesize chlorothiline, 2-chloro-5-chloromethylthiazole and 2-nitroiminoimidazolidine, in the reaction solvent, under the action of a catalyst, an electrophilic substitution reaction occurs, and the hydrogen chloride produced Adopt acid-binding agent to neutralize and condense to obtain chlorothialine product; Reaction equation: During the condensation reaction, if there is an excess of 2-nitroimidazolidine, the excess imidazolidine will precipitate along with the product, resulting in a decrease in the product content. Although the excess imidazolidine can be removed by increasing acid washing and water washing, it will increase significantly. The amount of waste water produced by the reaction; if 2-chloro-5-chloromethylthiazole is excessive, the probability of double-substituted side reactions will increase, resulting in a decrease in product content and yield, and the double-substituted by-products are difficult to remove from the product

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