ChemicalBook CAS DataBase List 1-Amino-2-naphthol-4-sulfonic acid

1-Amino-2-naphthol-4-sulfonic acid synthesis

4synthesis methods

Product Name:1-Amino-2-naphthol-4-sulfonic acid
CAS Number:116-63-2
Molecular formula:C10H9NO4S
Molecular Weight:239.25

2-Naphthol is dissolved in dilute aqueous sodium hydroxide and precipitated in finely divided form by addition of sulfuric acid at 5℃. Sodium nitrite solution is added to the slightly alkaline suspension, followed by sulfuric acid to effectthe nitrosation while the temperature is held at 5 – 8℃. The suspension of 1-nitroso2-naphthol is neutralized with aqueous sodium hydroxide; a solution of sodium bisulfite is then added. The temperature is allowed to rise to 20℃, and the soluble bisulfite addition complex is formed. Excess sulfuric acid is then added and the temperature is raised to 40℃, whereupon reductive rearrangement takes place and the product slowly crystallizes at 50℃. Filtration and washing give the product as a 25 % paste in 80 % yield. All plant items and reactants must be free from iron to avoid complex formation.

131-91-9 Synthesis

131-91-9
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$6.00/1g

116-63-2
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$5.00/5g

Yield:116-63-2 98.9%

Reaction Conditions:

Stage #1:1-Nitroso-2-naphthol with iron(III) chloride;pyrographite;sodium hydroxide in water at 60 - 65; for 0.75 h;Large scale;
Stage #2: with hydrazine hydrate in water for 6 h;Large scale;
Stage #3: with sulfuric acid;sodium sulfite in water; pH=7 - 8 at 60 - 65; for 12 h;Large scale;Concentration;Reagent/catalyst;

Steps:

6 Example 6
A hydrazine hydrate reduction method of 1-nitroso-2-naphthol was carried out by adding 175 kg of 1-nitroso-2-naphthol to 350 kg of water and adding 30 parts by mass of the mixture under stirring % Sodium hydroxide solution 8kg, activated carbon 2kg, then add FeCl3 · 6H20 solid 5kg, stirring heated to 60-65 ° C, continue stirring 45min, dropping 80% mass of hydrazine hydrate solution 120kg, drip, insulation reaction 6h, then 415kg of sodium sulfite was added in three times, and the time was 60min. During the process of adding sodium sulfite, the reaction solution was adjusted with 5% sulfuric acid solution at 7-8,60-65 ° C. The reaction solution was adjusted to 5-6 and allowed to stand for 30 min. Then, 238.2 kg of 1-amino-2-naphthol-4-sulfonic acid was obtained by pressure filtration, and the yield was 98.9 HPLC purity of 99.3%

References:

Jiujiang good water Technology Co;Nie, Feng;Feng, yu CN105669463, 2016, A Location in patent:Paragraph 0015

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