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New preparation method of 2-methyl-3-nitrobenzoic acid

A technology of nitrobenzoic acid and nitro-o-xylene, which is applied in the new field of preparation of 2-methyl-3-nitrobenzoic acid, can solve the problems of high pollution, high risk, and easy explosion, and achieve the cost of raw materials Low, less pollution, less dangerous effect

Active Publication Date: 2018-02-06
黄石市利福达医药化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The existing 2-methyl-3-nitrobenzoic acid product is oxidized by 3-nitro-o-xylene through dilute nitric acid, and an autoclave is used for high-pressure reaction, which is dangerous, explosive, and polluted by nitric acid-containing wastewater Larger, the by-products 2-methyl-6-nitrobenzoic acid and 3-nitrophthalic acid are more, and the yield can only be 27%. Because this method is dangerous and polluting, it causes enterprises to Unable to produce normally

Method used

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  • New preparation method of 2-methyl-3-nitrobenzoic acid

Examples

Experimental program
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Effect test

example 1

[0017] Example 1: Put 200g of 3-nitro-o-xylene, 700g of o-dichlorobenzene, 200g of n-hexanoic acid, 12g of cobalt acetate, 12g of manganese acetate, and 6g of tetrabromoethane into a 1000ml four-necked flask with a reflux condenser and a water separator. , feed oxygen to maintain 1.2L / min, raise the temperature to 90°C, keep the temperature at 90-100°C for 18 hours, and separate out about 23g of water, and control 3-nitro-o-xylene ≤ 1% in the sampling, which is the end point of the reaction, if the raw material More, continue to pass through the oxygen reaction until the end of the reaction; cool and filter to get 235g of crude product (containing solvent); the mother liquor is used as the next batch of solvent and then add a certain amount of catalyst, and add 5% of the original amount of catalyst, throw 3-Nitrate The base o-xylene reacts with oxygen again, and the result is the same as the original batch.

[0018] Put 235g of crude product, 1400ml of water, and 45g of causti...

example 2

[0019] Example 2: Put 200g of 3-nitro-o-xylene, 700g of o-dichlorobenzene, 300g of n-hexanoic acid, 4g of cobalt acetate, 2g of manganese acetate, and 4g of tetrabromoethane into a 1000ml four-necked flask with reflux condenser and water separator , keep the air at 3.5L / min, raise the temperature to 90°C, and keep the reaction at 90-100°C for 18 hours, and about 23g of water will be separated out. The control of 3-nitro-o-xylene in the sampling is ≤1%, which is the end point of the reaction. If the raw material More, continue the reaction with oxygen until the reaction reaches the end; cool and filter to obtain 240g of crude product (containing solvent).

[0020] Put 240g crude product into 2000ml four-necked bottle, 1400ml water, 29g purity is 99% caustic soda, heat up to 50-60 ℃, react for 30 minutes, place separatory funnel, separate oil 35g (use as next batch of reaction solvent) , return the water to the 2000ml four-neck bottle, add 6g of activated carbon, stir and decolo...

example 3

[0021] Example 3: Put 200g 3-nitro-o-xylene, 200g o-dichlorobenzene, 200g n-hexanoic acid, 10g cobalt acetate, 14g manganese acetate, 16g tetrabromoethane into a 1000ml four-necked bottle with reflux condenser and water separator , feed oxygen to maintain 1.0L / min, raise the temperature to 90°C, keep the temperature at 90-100°C for 18 hours, and separate out about 23g of water, and control 3-nitro-o-xylene ≤ 1% in sampling, which is the end point of the reaction, if the raw material More, continue to feed oxygen reaction, until the reaction reaches the end; cooling and filtering to get crude product 230g (containing solvent);

[0022] Drop into 230g crude product in the 2000ml four-necked bottle, 1400ml water, 73.7g purity is 99% caustic soda, is warming up to 50-60 ℃, reacts 30 minutes, is placed in separating funnel, separates oil 25g (uses as next batch reaction solvent) ), return the water to the 2000ml four-neck bottle, add 6g of activated carbon, stir and decolorize at 5...

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Abstract

The present invention relates to a kind of new preparation method of 2-methyl-3-nitrobenzoic acid, it is characterized in that carry out by following steps: add 3-nitro-o-xylene, organic solvent and catalyst in reactor, pass into oxygen Oxidation, the oxidation temperature is 90-100 °C, when the mass concentration of 3-nitro-o-xylene in the reactor is less than 1% as the reaction end point, the crude product is obtained by cooling and filtering, and the mother liquor is recovered and recycled; the crude product is sequentially subjected to conventional alkalization methods, The finished product of 2-methyl-3-nitrobenzoic acid is obtained by activated carbon decolorization and acidification. The method of the present invention replaces nitric acid oxidation 3-nitro-o-xylene with oxygen in the air to become 2-methyl-3-nitrobenzoic acid, and adopts oxygen to oxidize 3-nitro-o-xylene, reacts at normal pressure, and applies mechanically to the mother liquor. The yield is up to 80%, and the invention is a clean production method with little risk, little pollution and low cost of raw materials.

Description

technical field [0001] The invention relates to a new preparation method of 2-methyl-3-nitrobenzoic acid. Background technique [0002] The 2-methyl-3-nitrobenzoic acid product is made into 2-methyl-3-methoxybenzoic acid through reduction reaction, diazotization reaction and methoxylation reaction, while 2-methyl-3-methoxybenzoic acid Oxybenzoic acid is an important intermediate for the preparation of the new high-efficiency and low-toxicity dihydrazide insecticide methoxyfenozide, which is currently in short supply in the market. [0003] The existing 2-methyl-3-nitrobenzoic acid product is oxidized by 3-nitro-o-xylene through dilute nitric acid, and an autoclave is used for high-pressure reaction, which is dangerous, explosive, and polluted by nitric acid-containing wastewater Larger, the by-products 2-methyl-6-nitrobenzoic acid and 3-nitrophthalic acid are more, and the yield can only be 27%. Because this method is dangerous and polluting, it causes enterprises to Unabl...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C205/57C07C201/12
Inventor 包泉兴成家钢方日青
Owner 黄石市利福达医药化工有限公司
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