Method for producing 5-nitryl isophthalic acid

A technology of nitroisophthalic acid and nitro, which is applied in the field of preparation of 5-nitroisophthalic acid, can solve the problems of low yield, achieve the goal of increasing product yield, reducing pollution control costs, and reducing the generation of waste acid Effect

Inactive Publication Date: 2008-07-16
潘健
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

There are many ways to prepare this product, such as published by Chemical Industry Press, edited by Xu Kexun, "Fine Organic Chemical Product Preparation Handbook" p.3-382, introducing the method of mixing nitration with fuming nitric acid and concentrated sulfuric acid, and then recrystallizing with water. The yield is 75%; another example is "Organic Synthesis" published by Beijing Institute of Technology Press and edited by Fan Nengting, p.165-166, which introduces the use of a large amount of fuming nitric acid for reflux nitrification, distilling out the nitric acid to precipitate the crude product, and then using dilute nitric acid and water respectively. The washing method has a yield of 90%; there is also a report of using sulfuric acid as a solvent and nitrating with sodium nitrate, but the yield is lower

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  • Method for producing 5-nitryl isophthalic acid

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Comparison scheme
Effect test

Embodiment 1

[0013] (1) In a dry reaction flask, add 55 g of concentrated sulfuric acid and start stirring. Slowly add 23.9 g of fuming nitric acid dropwise under cooling in a water bath, controlling the temperature below 40°C. After the addition of nitric acid is completed, cool down to normal temperature to obtain mixed acid (II), which is ready for use.

[0014] (2) Add 30 g (0.18 mol) of isophthalic acid (I) into a dry and clean reactor, and then add 120 g of solvent (III), install a reflux condenser, start stirring, and heat to reflux.

[0015] (3) Under reflux, slowly add 78.9 g of mixed acid (II) dropwise, the rate of addition should not be too fast, and the addition is completed in about 2 hours.

[0016] (4) Continue the reflux reaction for 5h. After the reaction was completed, 90.8 g of the solvent (III) was distilled off.

[0017] (5) Add the nitro substance into 150ml of cold water (or ice water), cool to room temperature and filter, add 50ml of cold water to soak and filter...

Embodiment 2

[0019] (1) In a dry reaction flask, add 60 g of concentrated sulfuric acid and start stirring. Slowly add 25 g of fuming nitric acid dropwise under cooling in a water bath. Control the temperature below 40°C, finish adding nitric acid, and cool to room temperature to obtain mixed acid (II) for later use.

[0020] (2) Add 30 g (0.18 mol) of isophthalic acid (I) into a dry and clean reactor, and then add 120 g of solvent (III), install a reflux condenser, start stirring, and heat to reflux.

[0021] (3) Under the reflux state, slowly add 85g of mixed acid (II) dropwise, the dropping speed should not be too fast, and the addition is completed in about 2 hours.

[0022] (4) The reflux reaction was continued for 5 h, and after the reaction was completed, 91 g of the solvent (III) was distilled off.

[0023] (5) Add the nitro substance into 150ml of cold water (or ice water), cool to room temperature and filter, add 50ml of cold water to soak and filter, then rinse the filter cake...

Embodiment 3

[0025] (1) In the dry reaction flask, add 63.5 g of concentrated sulfuric acid and start stirring. Slowly add 25.4 g of fuming nitric acid dropwise under cooling in a water bath. Control the temperature below 40°C, finish adding nitric acid, and cool to normal temperature to obtain the mixed acid (II) for later use.

[0026] (2) Add 30 g (0.18 mol) of isophthalic acid (I) into a dry and clean reactor, and then add 120 g of solvent (III), install a reflux condenser, start stirring, and heat to reflux.

[0027] (3) Under the reflux state, slowly add 88.9g of mixed acid (II) dropwise, the dropping speed should not be too fast, and the addition is completed in about 2 hours.

[0028] (4) Continue the reflux reaction for 5h. After the reaction was completed, 91.2 g of the solvent (III) was distilled off.

[0029] (5) Add the nitro substance into 150ml of cold water (or ice water), cool to room temperature and filter, add 50ml of cold water to soak and filter, then rinse the filt...

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Abstract

A method for preparing a 5-nitroisophthalic acid dissolves an isophthalic acid into a dichloromethane, stirs and heats to reflux, and then slowly drops a mixed acid of fuming nitric acid and sulfate to continue the refluxing reaction for 5 hours with a used account of the mixed acid for 2.4 to 3 times of the quality of the isophthalic acid. When the reaction is finished, a solvent is evaporated, and the nitro products are put into cold water to stay for being cooled to a room temperature and then filtered; the nitro products are then added a proper amount of water for immersion cleaning, leached by cold water, dried under a temperature of 105 DEG C for a plurality of hours to get the final product 5-nitroisophthalic acid. Adopting the method of the invention can get the 5-nitroisophthalic acid with a theoretical yield of 93 percent and a purity to be equal to or higher than 99 percent.

Description

technical field [0001] The invention relates to a method for preparing 5-nitroisophthalic acid by using isophthalic acid as a starting material, using an organic solvent as a medium, and nitrating mixed acid. Background technique [0002] 5-Nitroisophthalic acid is widely used and is an important intermediate in the synthesis of medicine, pesticide and dye. There are many ways to prepare this product, such as published by Chemical Industry Press, edited by Xu Kexun, "Fine Organic Chemical Product Preparation Handbook" p.3-382, introducing the method of mixing nitration with fuming nitric acid and concentrated sulfuric acid, and then recrystallizing with water. The yield is 75%; another example is "Organic Synthesis" published by Beijing Institute of Technology Press and edited by Fan Nengting, p.165-166, which introduces the use of a large amount of fuming nitric acid for reflux nitrification, distilling out the nitric acid to precipitate the crude product, and then using di...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/57C07C201/08
Inventor 尹必华黄桂荣潘健
Owner 潘健
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