Novel process for efficiently and continuously synthesizing 2-naphthol

A high-efficiency, new process technology, applied in the field of organic chemical synthesis, can solve the problems of intermittent synthesis process, poor working conditions, high synthesis cost, etc., and achieve the effect of improved synthesis efficiency, stable performance, and reduced discharge of three wastes

Active Publication Date: 2010-07-21
QUJING ZHONGYI FINE CHEMICAL INDUSTRY CO LTD
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

At present, the main industrial method for synthesizing naphthol at home and abroad is still the sulfonation alkali fusion method, and its technology is relatively mature, but the sulfonation alkali fusion method has a long process flow, intermittent synthesis process, poor working conditions, serious equipment corrosion, and a lot of three wastes. , high synthesis cost and other disadvantages

Method used

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  • Novel process for efficiently and continuously synthesizing 2-naphthol
  • Novel process for efficiently and continuously synthesizing 2-naphthol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Naphthalene is sulfonated with 96% sulfuric acid at 155-165°C to mainly obtain 2-naphthalenesulfonic acid (content 85%), 1-naphthalenesulfonic acid (content 10%), add sodium sulfite (by-product during alkali fusion) It was precipitated, heated and concentrated to obtain 2-naphthalenesulfonic acid sodium salt. Then carry out alkaline melting of 2-naphthalenesulfonate sodium in a stirred cast iron or zinc steel kettle. First add 50% sodium hydroxide solution, heat to 300°C, add 2-naphthalenesulfonate sodium after dehydration, and keep at 320°C for about 3h. After the melt is dissolved in water, sulfur dioxide is added for acidification, neutralized to weakly alkaline (pH=8), after phase separation, the organic phase is crude naphthol, and the aqueous phase is mixed with tributyl phosphate, toluene 1:1 (v / v) mixed solvent to extract naphthol, and rectify together with the organic phase, reclaim the solvent, and obtain 2-naphthol and 1-naphthol. The purity of 2-naphthol ...

Embodiment 2

[0029] Naphthalene is sulfonated with 96% sulfuric acid at 140-155°C to mainly obtain 2-naphthalenesulfonic acid (content 85%), 1-naphthalenesulfonic acid (content 10%), adding sodium sulfite (by-product during alkali fusion) to make After precipitation, heating and concentration, 2-naphthalenesulfonic acid sodium salt was obtained. Then dissolve the sodium 2-naphthalenesulfonate in a stirred cast iron or zinc steel kettle. First add 50% sodium carbonate solution, heat to 250°C, add 2-sodium naphthalenesulfonate after dehydration, and keep at 300°C for about 3h. After the melt is dissolved in water, dilute sulfuric acid is added for acidification, neutralized to weakly alkaline (pH=8), after phase separation, the organic phase is crude naphthol, and the aqueous phase is extracted with a trioctylamine solvent to increase the concentration of naphthol. The yield is rectified together with the organic phase, and the solvent is recovered to obtain 2-naphthol and 1-naphthol. The ...

Embodiment 3

[0031] Naphthalene is sulfonated with 96% sulfuric acid at 160-170°C to mainly obtain 2-naphthalenesulfonic acid (content 85%) and 1-naphthalenesulfonic acid (content 10%), which are precipitated by adding sodium hydroxide solution, heated and concentrated Finally, the sodium salt of 2-naphthalenesulfonic acid was obtained. Then dissolve the sodium 2-naphthalenesulfonate in a stirred cast iron or zinc steel kettle. First add 50% sodium sulfite solution, heat to 300°C, add 2-naphthalenesulfonate sodium after dehydration, and keep at 350°C for about 3h. After the melt is dissolved in water, dilute sulfuric acid is added for acidification, neutralized to weakly alkaline (pH=8), after phase separation, the organic phase is crude naphthol, and the aqueous phase is mixed with tributyl phosphate, toluene 1:1 (v / v) mixed solvent to extract, to improve the yield of naphthol, together with the rectification of the organic phase, reclaim the solvent to obtain 2-naphthol and 1-naphthol....

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Abstract

The invention discloses a novel process for efficiently and continuously synthesizing 2-naphthol, which comprises the following steps of: (A) putting refined naphthol from a naphthol-melting tank (1) into a prime kettle of a sulfonation reaction kettle, respectively putting sulphuric acid into various levels of the sulfonation reaction kettle from a sulphuric acid-weighting tank (2) for a sulfonation reaction for 2-6h and reducing the pressure of the sulfonation reaction kettle so as to remove water generated by the reaction; (B) guiding a sulfonated product in the step (A) into a neutralizing tank (7), directly neutralizing with diluted alkali, keeping impurities in the sulfonation reaction, primarily evaporating to dewater and directly guiding into an alkali melting pot (9) for an alkali-melting reaction; (C) acidifying an alkali-melting reaction product in an acidifying tank (11) and extracting 2-naphthol and 1-naphthol from the alkali-melting reaction product in an extracting tower (13) with an extracting agent; and (D) rectifying an organic phase after extracting the naphthol in a rectification tower to recycle the extracting agent and rectifying and separating the 2-naphthol, the 1-naphthol and naphthol without participating the reaction. The invention adopts continuous reaction process design, has simple and convenient process, stable performance and high yield, overcomes the detects of intermittent operation, low synthesis effect, multiple steps for separating 2-naphthol from other impurities, low separation efficiency and much three-waste generation in a sulfonation alkali-melting 2-naphthol synthesis process of the prior art, realizes continuous process, greatly reduces three-waste emission, lessens wastewater by 20 percent than that of the traditional process, greatly improves the 2-naphthol synthesis efficiency and obtains the 1-naphthol as a byproduct.

Description

technical field [0001] The invention belongs to the technical field of organic chemical synthesis, and in particular relates to a new process capable of continuously synthesizing 2-naphthol with high efficiency. Background technique [0002] 2-Naphthol, also known as ethyl naphthol and β-naphthol, is an important organic chemical raw material and synthetic intermediate. There are more than 130 kinds of dyes and pigments directly synthesized from it, and more than 20 dye intermediates. It is also widely used in medicine, pesticides, rubber additives, spices, leather tanning, textile printing and dyeing additives, and mineral processing agents. In terms of dyestuffs, the main derivatives of 2-naphthol are 2,3-acid, Turmeric acid, diazonaphtholsulfonic acid, G acid, R acid, Y acid, J acid, 2,6 acid, etc.; In terms of medicine and pesticides, 2-naphthol is mainly used in the synthesis of anti-inflammatory analgesic naproxen, herbicide naproxen, plant regulator 2-naphthyloxyethy...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C39/14C07C37/04
Inventor 李桂成罗国林
Owner QUJING ZHONGYI FINE CHEMICAL INDUSTRY CO LTD
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