81-19-6Relevant academic research and scientific papers
Method for synthesizing 2 and 6 - dichlorobenzyl
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Paragraph 0016-0020, (2021/11/03)
The invention discloses a synthesis 2. The method comprises the following steps: 6 - 2-dichlorobenzene is heated to 6 - DEG C, chlorine is slowly introduced under illumination conditions, and the temperature is raised to 90 - 110 °C; and when the content of 120 - 140 °C and 2 dichlorobenzyl is more than 6 - the reaction is stopped and the nitrogen is slowly introduced into the system superfluous chlorine gas and the chlorinated liquid is slowly introduced to 50 - 60% 98%, and then subjected to vacuum rectification. 40 - 50 °C and 2-dichlorobenzyl chloride are added dropwise to obtain 2 6 -dichlorobenzyl chloride 6 . The method sequentially adopts a photo-chlorination and catalytic chlorination reaction method. The chlorination reaction temperature and the chlorine passing speed are adjusted, 2, 6 - dichlorotoluene conversion rate is high, the catalyst use amount is small, the generated 2 and 6 -dichlorobenzyl yield is high. The byproduct 2, 6 -dichlorobenzyl, 2, 6 -dichlorobenzyl is low in content, the rectification procedure is simplified, the production cost is reduced, and the industrial popularization is easy.
Method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis
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Paragraph 0017-0019, (2020/10/14)
The invention discloses a method for preparing 2, 6-dichlorobenzaldehyde by hydrolysis. The method comprises the following steps: heating 2, 6-dichlorobenzyl chloride to 120-160 DEG C, adding a pi complex formed by 0.05-6wt% of a metal salt and benzaldehyde or a benzaldehyde derivative as a catalyst, slowly dropwise adding water with the molar weight equal to that of the 2, 6-dichlorobenzyl chloride, stopping reaction when the content of the 2, 6-dichlorobenzyl chloride is lower than 0.05 wt% to obtain a 2, 6-dichlorobenzaldehyde crude product, and refining to obtain the 2, 6-dichlorobenzaldehyde. 2, 6-dichlorobenzyl chloride is used as a raw material, the used catalyst is the pi complex formed by the metal salt and benzaldehyde, the solubility of the reaction raw material 2, 6-dichlorobenzyl chloride is increased, a homogeneous reaction system is formed, the usage amount is small, a hydrolysis reaction can be initiated at a low temperature, and the reaction is stable. The method has the advantages of mild reaction conditions, high yield, few side reactions and environmental friendliness.
Synthesis method of insecticide teflubenzuron and intermediate 2,6-difluorobenzamide of insecticide teflubenzuron
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Paragraph 0056-0057; 0064-0065; 0072-0073, (2020/12/10)
The invention discloses a synthesis method of an insecticide teflubenzuron and an intermediate 2,6-difluorobenzamide of the insecticide teflubenzuron, belonging to the field of pesticides. The synthesis method comprises the following steps: step 1, preparation of 2,6-dichlorobenzylidene chloride: preparing turbid liquid of dichlorotoluene and phosphorus pentachloride, introducing chlorine gas, layering materials by utilizing a gas-liquid separator, collecting a crude product, and rectifying the crude product to obtain the 2,6-dichlorobenzylidene chloride; and 2, preparation of 2,6-dichlorobenzonitrile: mixing 2,6-dichlorobenzylidene chloride, acetic acid, zinc chloride, hydroxylamine hydrochloride and sodium acetate, carrying out heating for a reflux reaction, conducting cooling, stirring,filtering and drying successively after the reaction is completed so as to obtain 2, 6-dichlorobenzonitrile. By adopting a one-pot method, a reaction route is shortened, total yield is increased to 67.3% from conventional 55.4%, and cost is greatly reduced.
