- Method for synthesizing 2 and 6 - dichlorobenzyl
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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.
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Paragraph 0016-0020
(2021/11/03)
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- Method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis
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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.
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Paragraph 0017-0019
(2020/10/14)
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- Synthesis method of insecticide teflubenzuron and intermediate 2,6-difluorobenzamide of insecticide teflubenzuron
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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.
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Paragraph 0056-0057; 0064-0065; 0072-0073
(2020/12/10)
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