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Method for preparing 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate

A technology of acid oxygen body and nitrate body, which is applied in the field of preparation of 6-nitro-1,2,4-acid oxygen body, can solve the problems of heating, consumption of co-solvent, increase of cost, etc., and achieve high reaction yield and reaction Yield improvement and cost reduction effects

Active Publication Date: 2020-06-02
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this method dissolves 2-naphthol with water, it needs to consume cosolvent or heat, which increases the cost
In addition, whether the above three methods are adding sodium bisulfite or sodium pyrosulfite, a large amount of solid waste will be generated, and the nitrosation, sulfonation, nitration, etc. are all dangerous processes. The reaction route is still carried out by the traditional kettle process. There are certain hidden dangers

Method used

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  • Method for preparing 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate
  • Method for preparing 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate
  • Method for preparing 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] (1) Nitrosation reaction

[0034] Weigh 72.0 g of 2-naphthol and add it to 144.0 g of water, stir at room temperature for beating for 30 min, then add 84.5 g of 41% sodium nitrite solution, continue stirring for 10 min, and beat through pump A (the flow rate of the raw material solution is 11 mL / min). into the tubular reactor, and simultaneously pump 20% dilute sulfuric acid into the tubular reactor through pump B (the flow rate is 5mL / min). in, then filter at room temperature, and the filter cake is washed with water until the Congo red test paper does not change color, and 85.3 g of the yellow product is obtained, and the yield is 97%, and its content measured by HPLC is 98.6%.

[0035] (2) Catalytic hydrogenation reaction

[0036] Add 83.4 g of the prepared 1-nitroso-2-naphthol into 417.0 g of water, stir at room temperature until dissolved, and simultaneously open pump C and hydrogen pressure reducing valve, pump C (flow rate is 2 mL / min), Hydrogen flows into the ...

Embodiment 2

[0042] (1) Nitrosation reaction

[0043] Weigh 72.0 g of 2-naphthol and add it to 360.0 g of water, stir at room temperature for beating for 30 min, then add 84.5 g of 41% sodium nitrite solution, continue stirring for 10 min, and beat through pump A (the flow rate of the raw material solution is 10 mL / min). into the tubular reactor, while pumping 50% dilute sulfuric acid into the tubular reactor through pump B (the flow rate is 2.1mL / min), the tubular reactor is placed at 30°C, the residence time is 5min, and the reaction solution flows into the bottle, then filter at room temperature, and the filter cake is washed with water until the Congo red test paper does not change color, and 82.5 g of the yellow product is obtained, and the yield is 93%, and its content measured by HPLC is 97.3%.

[0044] (2) Catalytic hydrogenation reaction

[0045]Add 82.5 g of the prepared 1-nitroso-2-naphthol into 825.0 g of water, stir at room temperature until dissolved, and simultaneously open...

Embodiment 3

[0051] Recover and apply mechanically: take 2-naphthol 72.0g and join in 144.0g water (recovered filtrate), stir beating for 30min at room temperature, then add 84.5g of 41% sodium nitrite solution, continue to stir for 10min and pass through pump A ( The flow rate of the raw material liquid is 11mL / min) into the tubular reactor, and at the same time, 20% dilute sulfuric acid is injected into the tubular reactor through pump B (the flow rate is 5mL / min), and the tubular reactor is placed at 0° C. The time was 30min, the reaction solution flowed into the receiving bottle, then filtered at room temperature, the filter cake was washed with water until the Congo red test paper did not change color, and 83.7g of the yellow product was obtained, the yield was 95%, and its content was 98.3% as measured by HPLC.

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Abstract

The invention discloses a method for preparing 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate. The method comprises the following steps: carrying out a nitrosation reaction on 2-naphthol serving as a raw material, sodium nitrite and dilute sulfuric acid in a tubular reactor to generate 1-nitroso-2-naphthol, carrying out catalytic hydrogenation on the 1-nitroso-2-naphthol and hydrogen in a Raney nickel immobilized fixed bed reactor to generate 1-amino-2-naphthol, carrying out sulfonation diazotization cyclization on 1-amino-2-naphthol and nitrosyl sulfuric acid in the tubular reactor, and nitrifying with nitric acid to obtain the final product 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate. According to the novel synthesis method of the 6-nitro-2-diazo-1-naphthol-4-sulfonic acid hydrate, hydrogen is used for reduction in the route, nitrosyl sulfuric acid is used for sulfonation diazotization cyclization, so the problem that a large amount of solid waste is generated in a traditional route is avoided, the atom utilization rate is high, the yield is increased, the safety coefficient is increased by using a tubular process, and the method is suitable for industrial production.

Description

technical field [0001] The invention relates to a method for preparing 6-nitro-1,2,4-acid oxygen body. Background technique [0002] 6-nitro-1,2,4-acid oxygen body, its chemical name is 1,2-diazooxy-4-naphthalenesulfonic acid, is a naphthalene-based dye intermediate, and the naphthalene-based dye intermediate is An important category in the dye intermediate industry. [0003] At present, the synthetic route of 6-nitro-1,2,4-acid oxygen body reported in the literature is as follows: Han Changri et al. reported that 2-naphthol raw material and sodium hydroxide were used to form sodium salt, and the aqueous solution of sodium nitrite and dilute Sulfuric acid nitrosation, then sodium bisulfite and dilute sulfuric acid addition transposition reduction, then sodium nitrite diazonium ring closure, and finally nitration with nitric acid to generate 6-nitro-1,2,4-acid oxygen body, yield The rate is 60%. The nitrosation reaction of this method needs to be carried out in a very dilu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D271/12
CPCC07D271/12
Inventor 余志群黄佳佳谢士田苏为科
Owner ZHEJIANG UNIV OF TECH
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