Method for synthesizing 2,3-dioxynaphthalene
A technology of dihydroxynaphthalene and additives, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problems of burning raw materials, high energy consumption, and reducing the amount of alkali used, and achieve mild reaction conditions, The effect of low energy consumption
Active Publication Date: 2018-08-17
柏盛新材料(甘肃)有限公司
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Problems solved by technology
[0003] At present, the industrial synthesis of 2,3-dihydroxynaphthalene is still based on traditional sulfonation and alkali fusion processes, but a large amount of alkali is required in the production process, and a large amount of salty wastewater is generated, and high temperature alkali fusion The temperature is often above 300°C and the energy consumption is high
In the prior art, there have been some introductions about methods for synthesizing 2,3-dihydroxynaphthalene. For example, in the method for synthesizing 2,3-dihydroxynaphthalene described in Chinese patents with application numbers 201710468914.4 and 201611096570.0, hydrogen oxidation is used A mixture of potassium and sodium hydroxide is used to carry out alkali fusion on sodium 2-naphthol-3,6-disulfonate, which can reduce the amount of alkali used to a certain extent, but the alkali fusion needs to be carried out at 340 ° C, while still A large amount of saline wastewater is produced; patents EP0479292 and JPH04338346 report the use of potassium hydroxide as an alkali fusion reagent, and under the auxiliary action of surfactant sodium oleate or sodium tetradecene sulfonate, hydrogenation of terphenyl or fat in an organic solvent Alkali fusion reaction is carried out in alicyclic mixed oil, but at a reaction temperature of 330°C, there are huge problems in the stability and safety of the surfactant and the corresponding organic solvent; the Chinese patent application number 201510185004.6 introduces the -Sodium naphthalene disulfonate replaces 2-naphthol-3,6-sodium disulfonate as a raw material to prepare 2,3-dihydroxynaphthalene, but the corresponding process still requires alkali fusion at high temperature and then acid neutralization; application The Chinese patent No. 201410135107.7 improves the acidic hydrolysis conditions of sodium 2,3-dihydroxynaphthalene-6-sulfonate, and uses acidic ionic liquid instead of concentrated sulfuric acid as a catalyst. Although this method reduces the amount of wastewater in the hydrolysis step , but its raw material 2,3-dihydroxynaphthalene-6-sulfonate sodium is still obtained by high temperature alkali fusion
[0004] In summary, in the prior art, the main problems in the method of synthesizing 2,3-dihydroxynaphthalene include: (1) need to use a large excess of sodium hydroxide, the usual molar amount of sodium hydroxide used is 1 / 2 of the substrate molar amount more than 6 times; (2) to neutralize excessive sodium hydroxide needs to consume a large amount of sulfuric acid or hydrochloric acid, and generate a large amount of saline wastewater, and the cost of wastewater treatment is high; (3) the temperature of high-temperature alkali fusion is often above 300°C, which not only consumes High, the high temperature of 300 ℃ is also easy to burn the raw materials into by-products
Method used
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Embodiment 1
[0021] In a 1000ml three-necked flask, add 512g of n-octane, then add 128g of naphthalene, 0.13g of 2,4,6-trimethylphenylcarbene copper, and 3.0g of tetrahexylammonium chloride, heat up to 50°C under stirring, and then 300 g of hydrogen peroxide (concentration: 30%) was added dropwise within 2 hours, and then the reaction was continued at 50° C. for 5 hours to stop the reaction. The aqueous phase was extracted three times with 100 g of n-octane, and the organic phases were combined. The organic phase was taken for liquid chromatography analysis, which showed that it contained 102.2 g of 2,3-dihydroxynaphthalene (63.9% yield).
Embodiment 2
[0023] In a 1000ml three-necked flask, add 512g of n-octane, then add 128g of naphthalene, 0.13g of 2,4,6-trimethylphenylcarbene copper, and 3.0g of tetrahexylammonium chloride, heat up to 50°C under stirring, and then 500 g of hydrogen peroxide (concentration: 30%) was added dropwise within 2 hours, and then the reaction was continued at 50° C. for 5 hours to stop the reaction. The aqueous phase was extracted three times with 100 g of n-octane, and the organic phases were combined. The organic phase was taken for liquid chromatography analysis, which showed that it contained 125.8 g of 2,3-dihydroxynaphthalene (yield 78.6%).
Embodiment 3
[0025] The catalyst is copper phenylcarbene, the rest are the same as in Example 2, and the yield of 2,3-dihydroxynaphthalene is 62.5%.
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The invention relates to a method for synthesizing 2,3-dioxynaphthalene. The method comprises the following steps: adding naphthalene, a catalyst and an auxiliary in a reaction solvent; heating to thetemperature of 30-70 DEG C while stirring; then dropwise adding hydrogen peroxide with the concentration being 30%; and reacting to obtain a 2,3-dioxynaphthalene solution. Compared with an existing process for preparing 2,3-dioxynaphthalene, the method for synthesizing 2,3-dioxynaphthalene is relatively low in cost and is environmentally friendly; a large number of acids and alkalis are requiredfor a traditional sulfonation and alkali fusion process and a large amount of acid-containing waste water caused by consumption of the large number of acids and alkalis are avoided, reaction conditions are gentle, energy consumption is low, and environmental protection is facilitated.
Description
technical field [0001] The invention relates to a method for synthesizing hydroxynaphthalene, in particular to a new method for synthesizing 2,3-dihydroxynaphthalene, belonging to the technical field of fine chemicals. Background technique [0002] 2,3-Dihydroxynaphthalene (CAS No.: 92-44-4) is an off-white or reddish powder, slightly soluble in water, soluble in alcohol and ether, it is widely used as dyes, pharmaceutical intermediates, hair dyes, Analytical reagents, etc. [0003] At present, the industrial synthesis of 2,3-dihydroxynaphthalene is still based on traditional sulfonation and alkali fusion processes, but a large amount of alkali is required in the production process, and a large amount of salty wastewater is generated, and high temperature alkali fusion The temperature is often above 300°C, and the energy consumption is high. In the prior art, there have been some introductions about methods for synthesizing 2,3-dihydroxynaphthalene. For example, in the met...
Claims
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IPC IPC(8): C07C37/60C07C39/14
CPCC07C37/60C07C39/14
Inventor 胡兴邦袁仲飞黄彩红
Owner 柏盛新材料(甘肃)有限公司