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Synthetic process of naphthol

A synthesis process, a technology of naphthol, is applied in the field of synthesis technology of organic compounds, and can solve the problems of decreasing reaction speed, reducing sulfuric acid, a large amount of waste water and waste salt, etc., and achieving the effects of simplified operation, high utilization rate and less waste water volume.

Inactive Publication Date: 2017-05-17
宁夏紫光川庆化工有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] In the above two processes, as the sulfonation reaction proceeds, the generated water will reduce the concentration of sulfuric acid and reduce the reaction rate
In order to maintain the reactivity, the most traditional process 1 promotes the reaction speed by adding a large excess of sulfuric acid, but the residual amount of naphthalene is still high, and the process is cumbersome to operate, and a part of naphthalene will be lost during the naphthalene blowing process, and it will produce A large amount of waste water and waste salt; although process 2 increases the utilization rate of sulfuric acid, the utilization rate of naphthalene decreases. Because naphthalene is sublimable and volatile, a part of naphthalene will be lost in the process of decompression steaming water and naphthalene steaming

Method used

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  • Synthetic process of naphthol
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  • Synthetic process of naphthol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] In a 1000-liter four-necked flask (equipped with a dropping funnel, the reflux tube is installed on the dropping funnel), add 129.3 g of naphthalene (content 99%, 1 mol) and 100 g of 1, 2-dichloroethane, and heat up to 60- 70°C, after the naphthalene is completely dissolved, add 100g (1mol) of sulfuric acid with a mass fraction of 98% into the flask dropwise within a few minutes. 2-dichloroethane and water, adjust the speed of 1, 2-dichloroethane in the lower layer to return to the flask to keep the reaction temperature at 110-120°C, take a sample for analysis after reflux for 5-6 hours, and the residual acid is reduced to 4 %, the residual naphthalene drops to about 2%, stop reflux, evaporate the remaining 1,2-dichloroethane in the flask, cool down to below 100°C after steaming, slowly add 210g of sodium sulfite aqueous solution with a mass fraction of 30% to neutralize Naphthalenesulfonic acid, collect the generated sulfur dioxide gas for subsequent acidification of s...

Embodiment 2

[0034] In a 1000-liter four-necked flask (equipped with a dropping funnel, the reflux tube is installed on the dropping funnel), add 129.3 g of naphthalene (content 99%, 1 mol) and 100 g of 1, 2-dichloroethane, and heat up to 60- 70°C, after the naphthalene is completely dissolved, add 103g (1.03mol) of sulfuric acid with a mass fraction of 98% into the flask dropwise within a few minutes, heat up to 110-120°C for reflux reaction, and collect the refluxed 1 , 2-dichloroethane and water, adjust the rate at which the lower 1,2-dichloroethane refluxes into the flask to keep the reaction temperature at 110-120°C, and take samples for analysis after 5-6 hours of reflux, and the residual acid drops to 4% or less, the residual naphthalene drops to about 1.8%, stop reflux, evaporate the remaining 1, 2-dichloroethane in the flask, cool down to below 100°C after steaming, slowly add 210g of sodium sulfite aqueous solution with a mass fraction of 30% and naphthalenesulfonic acid, collect...

Embodiment 3

[0036] In a 1000-liter four-necked flask (equipped with a dropping funnel, the reflux tube is installed on the dropping funnel), add 129.3 g of naphthalene (content 99%, 1 mol) and 100 g of 1, 2-dichloroethane, and heat up to 60- 70°C, after the naphthalene is completely dissolved, add 105g (1.05mol) of sulfuric acid with a mass fraction of 98% into the flask dropwise within a few minutes, and raise the temperature to 110-120°C for reflux reaction after the addition, and collect the refluxed 1 , 2-dichloroethane and water, adjust the rate at which the lower 1,2-dichloroethane refluxes into the flask to keep the reaction temperature at 110-120°C, and take samples for analysis after reflux for 5-6 hours, and the residual acid drops to 4% or less, the residual naphthalene drops to about 1.6%, stop reflux, evaporate the remaining 1, 2-dichloroethane in the flask, cool down to below 100°C after steaming, and slowly add 210g of sodium sulfite aqueous solution with a mass fraction of ...

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Abstract

The invention discloses a synthetic process of naphthol. The process comprises the followings steps: sulfonation, neutralization, alkali fusion, and acidification. The sulfonation step comprises the following steps: a sulfonation reaction is carried out for naphthalene and sulfuric acid whose mass fraction is 98% in the existence of a water carrying agent, a characteristic that the water carrying agent and water form an azeotrope is applied, water which is generated in the reaction is separated continuously from a reaction system, and naphthalene and sulfuric acid are nearly reacted completely. Obtained 1-naphthalenesulfonic acid is neutralized, alkali fusion and acidification are directly carried out in order to obtain a naphthol crude product. The process has the advantages of simplified operation, little low of naphthalene and sulfuric acid, high utilization rate, high naphthalene conversion rate which reaches 94% or above, low amount of waste water, and a few amount of sodium sulfate waste water which is only generated after multiple circulations.

Description

technical field [0001] The invention relates to a synthesis process of organic compounds. Background technique [0002] There are two main synthesis processes for naphthol: process 1 is to melt naphthalene at about 90°C, react at high temperature in the presence of excess sulfuric acid (about 1.5 times that of naphthalene), try to complete the reaction of naphthalene, and then blow naphthalene, Neutralization, cooling and crystallization to remove sulfate, alkali fusion, acidification, and rectification to obtain 1-naphthol and 2-naphthol; process 2 is to react naphthalene and sulfuric acid with distilled water under reduced pressure in the case of excessive naphthalene, until sulfuric acid reacts When it reaches a certain value, the remaining naphthalene is steamed and recovered, and the obtained naphthalenesulfonic acid is directly subjected to alkali fusion after neutralization, and then acidified and rectified to obtain 1-naphthol and 2-naphthol. [0003] In the above t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C37/055C07C39/14
CPCC07C37/055C07C37/64C07C303/06C07C303/32C07C39/14C07C39/235C07C309/35
Inventor 丁永良乐金波孙全何咏梅邱建雨王飞郑道敏
Owner 宁夏紫光川庆化工有限公司
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