Preparation method of 4-amino-2-sulfonic benzoic acid

A technology of sulfobenzoic acid and sulfobenzoic acid disodium salt, applied in the field of preparation of aromatic sulfonic acid, can solve problems such as environmental pollution, waste residue generation, low yield and the like, achieve high purity, high yield, High yield and purity effect

Active Publication Date: 2012-04-18
TIANJIN UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are few reports about the preparation method of 4-amino-2-sulfonic acid benzoic acid. It has been proposed to use p-nitrotoluene as a raw material to prepare the in

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0007] Preparation of 4-amino-2sulfobenzoic acid from sodium 2-methyl-5-nitrobenzenesulfonate:

[0008] Add 23.9g of 2-methyl-5-nitrobenzenesulfonate sodium and 200mL of 1mol / L sodium hydroxide aqueous solution into the oxidation reaction kettle, fill it with 0.1MPa air, heat to 120°C, react for 4 hours, and then cool , adjusted to a pH value of 6.3 with a mass fraction of 30% sulfuric acid. Take 22.4g of iron powder, add 100mL of water, add 0.5mL of concentrated sulfuric acid with a mass fraction of 98% and 0.3g of ammonium chloride as a catalyst, heat to boiling, and after reflux for 1h, slowly drop the above pH6.3 solution into Reduction was carried out in the reaction kettle, and then stirred and kept under reflux at a speed of 1500 rpm for 1 h. Cool the reduction solution to room temperature, adjust the reduction product to pH9 with sodium carbonate powder, and filter to remove iron sludge. The obtained filtrate is adjusted to pH 1 with a mass fraction of 30% sulfuric a...

example 2

[0010] Preparation of 4-amino-2sulfobenzoic acid from sodium 2-formyl-5-nitrobenzenesulfonate:

[0011] Add 25.3g of sodium 2-formyl-5-nitrobenzenesulfonate and 200mL of 1mol / L sodium hydroxide aqueous solution into the oxidation reaction kettle, stir and dissolve, fill with 0.1MPa air, heat to 120°C, After reacting for 4h, it was cooled. Adjust the pH to 6.3 with 30% dilute sulfuric acid. Take 22.4g of iron powder and add 100mL of water, add 0.5mL of concentrated sulfuric acid with a mass fraction of 98% and 0.3g of ammonium chloride as a catalyst, heat to boiling, and after reflux for 1h, slowly drop the above pH 6.3 solution into the reaction within 2h Reduction was carried out in the still, and then stirred and kept under reflux at a speed of 1500 rpm for 1 h. Cool the reducing solution to room temperature, adjust the pH to about 9 with sodium carbonate powder, and filter to remove iron sludge. The resulting filtrate was adjusted to pH 1 with sulfuric acid with a mass f...

example 3

[0013] Preparation of 4-amino-2-sulfobenzoic acid from 4,4'-dinitrodiphenylethane-2,2'-disulfonic acid disodium salt:

[0014] Add 23.8 g of 4,4'-dinitrodiphenylethane-2,2'-disulfonic acid disodium salt and 200 mL of an aqueous solution of 1 mol / L sodium hydroxide into the oxidation reaction kettle, and fill it with a 0.1 MPa Air, heated to 120°C, reacted for 4 hours, then cooled. Adjust the pH to 6.3 with 30% sulfuric acid. Take 22.4g of iron powder, add 100mL of water, add 0.5mL of concentrated sulfuric acid with a mass fraction of 98% and 0.3g of ammonium chloride as a catalyst, heat to boiling, and after reflux for 1h, slowly drop the above pH6.3 solution into Reduction was carried out in the reaction kettle, and then stirred and kept under reflux at a speed of 1500 rpm for 1 h. Cool the reducing solution to room temperature, adjust the pH to 9 with solid sodium carbonate, and filter to remove iron sludge. The resulting filtrate was adjusted to pH 1 with sulfuric acid w...

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PUM

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Abstract

The invention discloses a preparation method of 4-amino-2-sulfonic benzoic acid, and belongs to the preparation technology of aromatic sulfonic acid. The process of the method comprises the following steps: dissolving raw materials of p-nitrotoluene o-sodium sulfonate, 4-nitro-2- sodium sulfonate benzaldehyde, 4,4'-dinitro diphenylethane-2,2'-disodium disulfonate or 4,4'-dinitro diphenylethene-2,2'-disodium disulfonate in a sodium hydroxide solution, performing oxidation with pressurized air, performing reduction with iron powder, performing filtration and crystallization to obtain 4-amino-2-sulfonic benzoic acid. The invention has a simple process, high yield and purity, and the product 4-amino-2-sulfonic benzoic acid can be prepared into p-aminosalicylic acid through simple alkali fusion technology with high yield and high product purity.

Description

technical field [0001] The invention relates to a preparation method of 4-amino-2-sulfobenzoic acid, which belongs to the preparation technology of aromatic sulfonic acid. Background technique [0002] 4-Amino-2-sulfonic acid benzoic acid is an important pharmaceutical and chemical intermediate, its main purpose is to prepare a commonly used intermediate and drug - p-aminosalicylic acid through a simple alkali fusion process. P-aminosalicylic acid is mainly used in the preparation of anti-tuberculosis drug-sodium p-aminosalicylate, tuberculosis inhibitor-palsoniazid and anti-emetic drug-bromoanthranilide. In addition, p-aminosalicylic acid can also be used to prepare high polymer polymethacrylic acid amine p-aminosalicylic acid and insecticide. There are few reports about the preparation method of 4-amino-2-sulfonic acid benzoic acid. It has been proposed to use p-nitrotoluene as a raw material to prepare the intermediate, but potassium permanganate is used as the oxidant, ...

Claims

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Application Information

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IPC IPC(8): C07C309/61C07C303/22
Inventor 张凤宝彭文朝张国亮范晓彬戈建华段卫东
Owner TIANJIN UNIV
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