581-43-1Relevant articles and documents
Preparation method of 2, 6-dihydroxy naphthalene
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Paragraph 0024-0037, (2021/02/10)
The invention relates to a preparation method of 2, 6-dihydroxy naphthalene. A grinding vacuum reactor is adopted as a reactor so that mixed alkali and 2, 6-naphthalene disulfonate can be fully contacted and reacted in a solid phase state, the mixed alkali does not need to be heated to a molten state, and the mixed alkali compounded by alkali metal hydroxide and magnesium oxide is adopted, the addition of magnesium oxide can activate sulfo groups, the sulfo groups can be replaced by OH- more easily, a low-energy rapid path is realized, the reaction temperature is greatly reduced, the generation of byproducts such as tar is greatly reduced, and the conversion rate and the yield are improved.
Preparation process for synthesizing 2,6-dihydroxynaphthalene
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Paragraph 0020-0031, (2020/09/20)
The invention discloses a preparation process for synthesizing 2,6-dihydroxynaphthalene. The preparation process comprises specific steps as follows: (1) in an autoclave, adding 33-34 parts of 2,6-naphthalenedisulfonic acid disodium salt, 12-18 parts of sodium hydroxide and 50-52 parts of water, performing stirring and heating to 280-320 DEG C, and performing stirring for reaction at the temperature for 8-10 hours; (2) stirring the solution obtained after the reaction in the step (1) and cooling the solution to the room temperature, adding sulfuric acid with concentration of 40%-60%, and performing neutralization reaction until PH being 0.5-2; (3) filtering a suspension from the step (2), transferring filtered solids to a container, adding 150-152 parts of hexane, 0.1-0.15 parts of a copper salt catalyst and 1-1.5 parts of a phase transfer catalyst, performing stirring and heating to 30-60 DEG C, adding 12-50 parts of an oxidant with concentration of 20%-30%, and continuing reaction at30-70 DEG C for 2-4 hours to obtain a 2,6-dihydroxynaphthalene solution. The preparation process has the advantages that salt-containing wastewater is reduced, dosage of sodium hydroxide and potassium hydroxide is reduced, and the yield is significantly increased.
A 2,6-dihydroxynaphthalene synthetic method
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Paragraph 0029; 0031, (2016/12/12)
The invention discloses a synthetic method of 2,6 dihydroxy naphthalene, which comprises the following steps: placing 2,6 dihydroxy naphthalene in an alkali fusion pan, then a mixture of solid sodium hydroxide and nitrate is placed, Slowly heating to 150-170 DEG C, stirring, continuously heating to 320 DEG C, insulating for fusing alkali for 2.5-3.5 hours at 310-330 DEG C, then cooling to 200 DEG C, slowly dropping 450g of water for diluting, using a tri(octyl-decyl)amine solution for extracting 2,6-dihydroxy naphthalene, then acidifying the extracted 2, 6-dihydroxy naphthalene by sulfuric acid, and filtering and refining filter cake by an ethanol water mixed solvent to obtain 2,6-dihydroxy naphthalene. According to the synthetic method of 2,6-dihydroxy naphthalene, the used inorganic solvent is a mixture of potassium nitrate, sodium nitrite and sodium nitrate. According to the invention, viscosity of an alkali fusion material is low, fluidity is good, material can be uniformly mixed, and alkali fusion effect is good. In addition, under high temperature condition for alkali fusion, no decomposition problem of oxidation organic matter is generated, and no difficult separating problem is generated for the mixture.
