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Preparation method of 2,6-dihydroxynaphthalene

A technology of dihydroxynaphthalene and hydroxyl, which is applied in the field of preparation of 2,6-dihydroxynaphthalene, can solve the problems of unsuitability for industrial production, many oxidation by-products, and low product quality, and achieve a stable and safe reaction process and reduce tar generation , The effect of simple process operation

Inactive Publication Date: 2017-04-26
SHENYANG RES INST OF CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The raw materials of this process are not easy to obtain, and there are many by-products of oxidation, the product quality is low, and it is not suitable for industrial production

Method used

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  • Preparation method of 2,6-dihydroxynaphthalene
  • Preparation method of 2,6-dihydroxynaphthalene
  • Preparation method of 2,6-dihydroxynaphthalene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0051] (1) Add 200g of hydrogenated terphenyl and 50g of water into a 500ml four-necked bottle, slowly add 50.3g of 2,6-naphthalene disulfonic acid with a content of 80.11% (calculated as sulfuric acid, total acid content is 31.57%) while stirring, and stir Evenly, then slowly add 13.5g of 96% sodium hydroxide to neutralize 2,6-naphthalene disulfonic acid until neutral.

[0052] (2) Transfer the above-mentioned materials from the four-necked bottle to a stainless steel reaction kettle connected with a vacuum dehydration device, add 46.7g96% sodium hydroxide, 44.0g85% potassium hydroxide and 0.2g2,6-di-tert-butyl For p-cresol, close the reaction kettle, replace the air in the kettle with nitrogen three times, then start stirring, turn on the vacuum pump to -0.02MPa, slowly open the steaming valve of the reaction kettle to maintain the pressure in the kettle at -0.02MPa, heat up and distill water. When the temperature reaches 110°C, the water starts to flow out, and when it reac...

Embodiment 2

[0055] (1) Add 160g of hydrogenated terphenyl and 40g of water into a 500ml four-neck bottle, slowly add 39.4g of 2-hydroxy-6-naphthalenesulfonic acid sodium salt with a content of 87.39% while stirring, stir evenly, and then add 5.8g of 96% hydrogen Sodium oxide neutralizes the sodium salt of 2-hydroxy-6-naphthalenesulfonate to neutrality.

[0056] (2) Transfer the above material from the four-necked bottle to a stainless steel reaction kettle connected with a vacuum dehydration device, add 28.0g96% sodium hydroxide, 36.9g85% potassium hydroxide and 0.2g tetrakis (3,5-di tert-butyl-4-hydroxyhydrocinnamic acid) pentaerythritol ester, close the reactor, replace the air in the reactor with nitrogen for three times, then start stirring, turn on the vacuum pump to -0.02MPa, slowly open the steam valve of the reactor to maintain the pressure in the reactor as - 0.02MPa, heated up distilled water. When the temperature reaches 153°C, the water starts to flow out, and when it reaches...

Embodiment 3

[0059] (1) Add 140.2g of hydrogenated terphenyls recovered from the previous batch reaction, 9.8g of new hydrogenated terphenyls and 40g of water into a 500ml four-necked bottle, and slowly add 39.4g of 2-hydroxy-6-naphthalene with a content of 87.39% while stirring Sodium sulfonic acid, stir evenly, then add 8.2g of 85% potassium hydroxide to neutralize the sodium salt of 2-hydroxy-6-naphthalenesulfonic acid until neutral.

[0060] (2) Transfer the above-mentioned materials from the four-necked bottle to a stainless steel reaction kettle connected with a vacuum dehydration device, add 31.1g96% sodium hydroxide, 21.5g85% potassium hydroxide and 0.1g tetrakis (3,5-di Tert-butyl-4-hydroxyhydrocinnamic acid) pentaerythritol ester, close the reactor, replace the air in the reactor with nitrogen for three times, then start stirring, turn on the vacuum pump to -0.03MPa, slowly open the steam valve of the reactor to maintain the pressure in the reactor as - 0.03MPa, heated up distill...

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Abstract

The invention belongs to the field of organic synthesis and particularly relates to a preparation method of 2,6-dihydroxynaphthalene. The preparation method is characterized in that 2,6-naphthalene disulfonic acid or sodium 2-hydroxy-6-naphthalene sulfonate or potassium salt as a raw material is subjected to an alkali fusion reaction in hydrogenated terphenyl as an organic solvent under the action of a mixed base of sodium hydroxide and potassium hydroxide and the protection of an antioxidant; activated carbon is added in an acidification-out process for filtration aiding and adsorption decolorization treatment on an aqueous liquid, and a qualified product is obtained ultimately; an oil phase is recyclable for the next alkali fusion reaction. The preparation method has the advantages that the process is simple and convenient to operate, and the reaction process is smooth and safe; by means of the combined action of a protective agent and the low negative pressure, air cannot enter the reaction system during steaming to oxidize the material; with the adoption of the mixed base, the reaction temperature can be reduced, generation of tar can be reduced, and the alkali fusion activity of the reaction is guaranteed; the added activated carbon in a specific pH range plays an important role in tar adsorption, filtration of insoluble impurities, decolorization of a reaction liquid and the like.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a preparation method of 2,6-dihydroxynaphthalene. Background technique [0002] 2,6-dihydroxynaphthalene is a white or off-white flaky crystal. It is widely used in the fields of fibers, films, electronic components, medicine, dyes and rubber. It is an important intermediate for the preparation of certain polymer materials and liquid crystal resins. It has important application value. There are not many research reports on the preparation of 2,6-dihydroxynaphthalene at home and abroad, and there are relatively few manufacturers. However, based on the increasing demand for this product in the downstream industry in the future, a method suitable for the industrial production of 2,6-dihydroxynaphthalene has been developed. The process route is particularly important. [0003] Preparation of 2,6-dihydroxynaphthalene in the prior art includes the following three methods:...

Claims

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Application Information

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IPC IPC(8): C07C37/00C07C37/04C07C39/14C07C37/64C07C39/235
CPCC07C37/00C07C37/04C07C37/64C07C39/14C07C39/235
Inventor 王玉灿马瑛高嘉新
Owner SHENYANG RES INST OF CHEM IND
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