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Method for synthesizing 6-chloro-2-(p-hydroxyl)-phenoxy-benzoxazole

A technology of dichlorobenzoxazole and benzoxazole, which is applied in the field of chemical synthesis of pesticide intermediates, can solve the problems of excessive three wastes, excessive use of hydroquinone, black waste water, etc., and achieves environmental benefits and simplification difficulty. , the effect of reducing the dosage

Inactive Publication Date: 2009-02-25
JIANGSU TIANRONG GROUP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The existence of side reactions makes the yield of the final product low. In the production process, in order to prevent the occurrence of side reactions of di-ether, it is generally adopted to increase the amount of hydroquinone to suppress the occurrence of side reactions, but the amount of hydroquinone is greatly increased. Excessive not only brings a lot of waste of raw materials and increased cost, but also excessive hydroquinone will form black wastewater and waste residue, which makes the post-treatment of the target object and sewage treatment difficult, resulting in high cost, low yield, many three wastes, and difficult Governance, and its synthetic yield is only 80%

Method used

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  • Method for synthesizing 6-chloro-2-(p-hydroxyl)-phenoxy-benzoxazole
  • Method for synthesizing 6-chloro-2-(p-hydroxyl)-phenoxy-benzoxazole

Examples

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example 1

[0016] In a 1000ml four-necked bottle, drop 24g (percentage) of 96ml water solid caustic soda, 60 grams of hydroquinone, catalyst polyethylene glycol-200, and stir to dissolve 5 grams. Raise the temperature to 60°C, drop 94.25g of 2,6-dichlorobenzoxazole and 150ml of toluene into the four-necked flask at the same time, continue the reaction for 3 hours, raise the temperature to 100°C, and finish the reaction for 2 hours. After the distillation is complete, add water to cool, filter, and dry the filter cake to obtain 130 grams of finished product with a content of 92.50% and a molar yield of 92.14%.

[0017] Data:IR(KBr):v3265.8,3076.9,1862.9,1733.7,1632.1,1599.6,1574.6,1506.6,1465.1,1442.1,1358.0,1317.9,1274.5,1259.9,1219.0,1192.4,1157.4,1117.2,1096.0,1052.8,1004.0 cm -1 .

example 2

[0019] In a 1000ml four-necked bottle, put 24g (percentage) of solid caustic soda into 96ml of water, 60 grams of hydroquinone, catalyst polyethylene glycol 400, and stir to dissolve 5 grams. Raise the temperature to 60°C, drop 94.25g of 2,6-dichlorobenzoxazole and 150ml of toluene into the four-necked flask at the same time, continue the reaction for 4 hours, raise the temperature to 100°C, and finish the reaction for 2 hours. After the distillation is complete, add water to cool, filter, and dry the filter cake to obtain 132 grams of finished product with a content of 92.60% and a molar yield of 93.66%.

example 3

[0021] In a 1000ml four-necked bottle, drop 26g (percentage) of water solid caustic soda into 105ml, 66 grams of hydroquinone, catalyst polyethylene glycol 800, and stir to dissolve 6 grams. Raise the temperature to 65°C, drop 94.25g of 2,6-dichlorobenzoxazole and 150ml of toluene into the four-necked flask at the same time, continue the reaction for 2 hours, raise the temperature to 100°C, and finish the reaction after 2 hours, distill the toluene-water to the toluene After the distillation is complete, add water to cool, filter, and dry the filter cake to obtain 131 grams of finished product with a content of 92.46% and a molar yield of 92.81%.

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Abstract

The invention discloses a method for synthesizing 6-chlorine-2-(para hydroxyl)-phenoxyl-benzoxazole, which comprises the steps: hydroquinone, alkali and catalyst are dissolved in the water; after the temperature raises to 40-80 DEG C, the mixture is added with 2, 6-dichlorobenzoxazole and toluene to react for 0.5-6 hours, and then the temperature raises to 80-120 DEG C to continuously react for 0.5-4 hours; when the reaction is finished, the 6-chlorine-2-(para hydroxyl)-phenoxyl-benzoxazole is obtained by separation; wherein, the weight ratio of the alkali, the hydroquinone, the catalyst and the 2, 6-dichlorobenzoxazole is 15-30:45-75:1-10:80-110. The method inhibits the occurrence of side reaction, improves the yield of reaction, saves the cost, better simplifies the difficulty of sewage disposal, and is more beneficial to the environment.

Description

technical field [0001] The invention belongs to the field of pesticide synthesis, and in particular relates to a chemical synthesis method of a pesticide intermediate. Background technique [0002] 6-Chloro-2-(p-hydroxy)-phenoxy-benzoxazole is a phenoxy hydroxyacid herbicide, fenoxaprop-methyl (chemical name: 2-[4-(6-chloro-2 -benzoxazolyloxy group) phenoxyl group] ethyl propionate) its synthetic method is generally as an important intermediate: [0003] [0004] And in above-mentioned reaction can produce following side reaction: [0005] [0006] The existence of side reactions makes the yield of the final product low. In the production process, in order to prevent the occurrence of side reactions of di-ether, it is generally adopted to increase the amount of hydroquinone to suppress the occurrence of side reactions, but the amount of hydroquinone is greatly increased. Excessive not only brings a lot of waste of raw materials and increased cost, but also excessive ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D263/58
Inventor 许网保魏明阳金克明周国平虞国新唐良才徐卫清
Owner JIANGSU TIANRONG GROUP