CA1263868A - Process for producing aromatic hydroxycarboxylic acids - Google Patents
Process for producing aromatic hydroxycarboxylic acidsInfo
- Publication number
- CA1263868A CA1263868A CA000508469A CA508469A CA1263868A CA 1263868 A CA1263868 A CA 1263868A CA 000508469 A CA000508469 A CA 000508469A CA 508469 A CA508469 A CA 508469A CA 1263868 A CA1263868 A CA 1263868A
- Authority
- CA
- Canada
- Prior art keywords
- reaction
- aromatic hydroxy
- hydroxy compound
- alkali metal
- aromatic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
ABSTRACT
This invention provides a process for selec-tively producing aromatic hydroxycarboxylic acids, which comprises subjecting a liquid mixture consisting of a polycyclic aromatic hydrocarbon, an alkali metal salt of an aromatic hydroxy compound and a free aromatic hydroxy compound to a reaction with carbon dioxide. The process permits the production of the intended product with enhanced selectivity.
This invention provides a process for selec-tively producing aromatic hydroxycarboxylic acids, which comprises subjecting a liquid mixture consisting of a polycyclic aromatic hydrocarbon, an alkali metal salt of an aromatic hydroxy compound and a free aromatic hydroxy compound to a reaction with carbon dioxide. The process permits the production of the intended product with enhanced selectivity.
Description
S P E C I ~ I C A T I O N
PROCESS FOR PRODUCING AROMATIC HYDRO~YCA~BOXYLIC ACIDS
Field of Technolo~y This invention relates to a process for selectively producing aromatic hydroxycarboxyllc acids, which comprises liquefying an alkali metal salt of an aromatic hydroxy compound with an added aromatic hydroxy compound, followed by reaction with carbon dioxide in a liquid-liquid mixture with an medium.
Background Technology Aromatic hydroxycarboxylic acids~ particularly p-hydroxybenzoic acid, salicylic acid, 2-hydroxy-3-naphthoic acid, etc., have long been known for its usefulness as a raw material for the production of antiseptic and antifungal agents, pharmaceuticals, dyestuffs, pigments and the like, and in recent years, have furthermore acquired increasingly greater importance not only as a starting compound for the synthesis of agricultural chemicals, color developing agents for thermosensitive recording paper, etc. but also as a monomer for aromatic polyesters.
$hese aromatic hydroxycarboxylic acids have conventionally been produced by means of the so-called Kolbe-Schmitt process involving a vapor-solid phase reaction of an alkall metal salt of aromatic hydroxy compound with carbon dioxide. Lately~ one of the present inventors has improved the said vapor-solid phase re-action process into the liquid-solid phase reaction process making use of a suspension phase, and thus, there has been established a process which permits an industrial-scale, mass-production of such aromatic hydroxycarboxylic acids [refer to the specification of Patent Application No. 39281/1983 (Laid Open Patent Publication No. 164751/1984)].
Disclosure of the Invention The present inventors, with a specific view -to further improving the process, carried out repeated ~ ,r ~q2~3~8 research, and ~ound that diaryl or triaryl based poly-cyclic aromatic hydrocarbons remaining liquid at ambient temperature and showing a boiling point of not less than 250C can produce excellent efrects under conditions of an added aromatic hydroxy compound. The finding has led to the completion of this invention.
This invention is directed to a process ~or selectively producing aromatic hydroxycarboxylic acids, characterized in that the said process comprises allowing a liquid mixture consisting o~ a polycyclic aromatic hydrocarbon, alkali metal salt of an aromatic hydroxy compound and free aromatic hydroxy compound to undergo reaction with carbon dioxide.
The present invention can achieve the ~ollowing effects:
(l) The media of this invention can suspend thoroughly alkali metal salts of aromatic hydroxy com-pounds, which permits the complete dehydration of such alkali metal salts of aromatic hydroxy compounds to be performed promptly and at relatively lowered temper~
atures. Consequently, there can be easlly obtained anhydrous alkali metal salts of aromatic hydroxy com~
pounds as a raw material, which3 when admixed with aromatic hydroxy compounds and the reaction medium and subJected to a reaction with carbon dioxide, contribute to outstandingly improved yields of the ob~ective com-pound to be obtained in such a reaction.
PROCESS FOR PRODUCING AROMATIC HYDRO~YCA~BOXYLIC ACIDS
Field of Technolo~y This invention relates to a process for selectively producing aromatic hydroxycarboxyllc acids, which comprises liquefying an alkali metal salt of an aromatic hydroxy compound with an added aromatic hydroxy compound, followed by reaction with carbon dioxide in a liquid-liquid mixture with an medium.
Background Technology Aromatic hydroxycarboxylic acids~ particularly p-hydroxybenzoic acid, salicylic acid, 2-hydroxy-3-naphthoic acid, etc., have long been known for its usefulness as a raw material for the production of antiseptic and antifungal agents, pharmaceuticals, dyestuffs, pigments and the like, and in recent years, have furthermore acquired increasingly greater importance not only as a starting compound for the synthesis of agricultural chemicals, color developing agents for thermosensitive recording paper, etc. but also as a monomer for aromatic polyesters.
$hese aromatic hydroxycarboxylic acids have conventionally been produced by means of the so-called Kolbe-Schmitt process involving a vapor-solid phase reaction of an alkall metal salt of aromatic hydroxy compound with carbon dioxide. Lately~ one of the present inventors has improved the said vapor-solid phase re-action process into the liquid-solid phase reaction process making use of a suspension phase, and thus, there has been established a process which permits an industrial-scale, mass-production of such aromatic hydroxycarboxylic acids [refer to the specification of Patent Application No. 39281/1983 (Laid Open Patent Publication No. 164751/1984)].
Disclosure of the Invention The present inventors, with a specific view -to further improving the process, carried out repeated ~ ,r ~q2~3~8 research, and ~ound that diaryl or triaryl based poly-cyclic aromatic hydrocarbons remaining liquid at ambient temperature and showing a boiling point of not less than 250C can produce excellent efrects under conditions of an added aromatic hydroxy compound. The finding has led to the completion of this invention.
This invention is directed to a process ~or selectively producing aromatic hydroxycarboxylic acids, characterized in that the said process comprises allowing a liquid mixture consisting o~ a polycyclic aromatic hydrocarbon, alkali metal salt of an aromatic hydroxy compound and free aromatic hydroxy compound to undergo reaction with carbon dioxide.
The present invention can achieve the ~ollowing effects:
(l) The media of this invention can suspend thoroughly alkali metal salts of aromatic hydroxy com-pounds, which permits the complete dehydration of such alkali metal salts of aromatic hydroxy compounds to be performed promptly and at relatively lowered temper~
atures. Consequently, there can be easlly obtained anhydrous alkali metal salts of aromatic hydroxy com~
pounds as a raw material, which3 when admixed with aromatic hydroxy compounds and the reaction medium and subJected to a reaction with carbon dioxide, contribute to outstandingly improved yields of the ob~ective com-pound to be obtained in such a reaction.
(2) A mixture consisting of an anhydrous alkali metal salt of aromatic hydroxy compound, aromatic hydroxy compound and a reaction medium has their components all kept in the liquid form and suspended thoroughly and uni~ormly under reaction conditions, and can be trans-ported in a quantitative manner9 which secures the constant reaction yield in the continuous production process.
(3) The improvement o~ both yield and selectivity is of utmost importance in the Kolbe-Schmltt reaction~
3~3 where the production of isomers is always involved and basically inevitable owing to the principle of orienta-tion in the aromatic substitution reaction. In the conventional Kolbe-Schmitt reaction processes, the pro-duction of isomers takes place9 in spite o~ the reactionconditions, inclusive of temperature and pressure, being optiomally set to minimize the isomer production. How-ever, this invention constitutes a process which keeps the starting material system in the liquid ~orm under reaction conditions and consequently suppresses markedly the production of isomers9 permitting the objective compound to be formed in the outstandingly improved selectivity, as compared with the solid-liquid suspension system in the conventional processes.
Thus, in the said reaction where aromatic hydroxycarboxylic acids are formed, the supplementary addition of an aromatic hydroxy compound allows the mutual affinity among three compounds of the aromatic hydroxy compound, the alkali metal salt of an aromatic hydroxy compound and the reaction medium to be optimally regulated, which can control the orientation direction in the said reaction and can also enhance outstandingly the selectivity.
3~3 where the production of isomers is always involved and basically inevitable owing to the principle of orienta-tion in the aromatic substitution reaction. In the conventional Kolbe-Schmitt reaction processes, the pro-duction of isomers takes place9 in spite o~ the reactionconditions, inclusive of temperature and pressure, being optiomally set to minimize the isomer production. How-ever, this invention constitutes a process which keeps the starting material system in the liquid ~orm under reaction conditions and consequently suppresses markedly the production of isomers9 permitting the objective compound to be formed in the outstandingly improved selectivity, as compared with the solid-liquid suspension system in the conventional processes.
Thus, in the said reaction where aromatic hydroxycarboxylic acids are formed, the supplementary addition of an aromatic hydroxy compound allows the mutual affinity among three compounds of the aromatic hydroxy compound, the alkali metal salt of an aromatic hydroxy compound and the reaction medium to be optimally regulated, which can control the orientation direction in the said reaction and can also enhance outstandingly the selectivity.
(4) The reaction media exhibit a high degree of affinity not only for aromatic hydroxy compounds but also for alkali metal salts of aromatic hydroxy compounds, and when mixed with them to form a liquid-liquid mixture of the three components, provlde a highly good suspension state, resultlng ln improvement in the rate of reaction step and the yield of the ob~ective compound.
(5) The process of this lnvention, whlch suppresses the converslon lnto tar o~ the reaction pr-oduct ln the reactlon step and allows the tarry by-products to dis-solve in the reaction medium layer, minimlzes the con-taminatlon of tarry substances lnto a layer of the alkallmetal salt of aromatic hydroxy compound, thus preventing reductions in reactlon rate and in yield and proportion ~3~
of the desired compound owlng to contamlnation of tarry substances.
of the desired compound owlng to contamlnation of tarry substances.
(6) The above-described reactlon media, because of their increased distribution ratlo for aromatic hydroxy compounds, allow aromatlc hydroxy compounds to immlgrate lnto the water layer to a mlnimal extent, and con-sequently facllltate the recovery of aromatic hydroxy compounds. Thls, coupled with a reduced degree of contaminatlon of tarry substances into the water layer, elimlnates the extractlon step wlth organic solvents, etc. for the water layer in the finishing treatment step~
while securing the direct production of the obJective compound from the water layer.
while securing the direct production of the obJective compound from the water layer.
(7) The above-mentioned reaction media demonstrate excellent thermal stability at increased temperatures even in the presence of alkali metal salts of aromatic hydroxy compounds. Since the loss as a result of thermal degradation is small, it is economically advantageous.
(8) The aforesaid reaction media not only enhance~
the yield and percentage obtained of the intended product, but also since the media themselves possess superior thermal stability, the production of impurities is reduced, and this f`acilitates the treatment procedure in the finishing treatment step.
the yield and percentage obtained of the intended product, but also since the media themselves possess superior thermal stability, the production of impurities is reduced, and this f`acilitates the treatment procedure in the finishing treatment step.
(9) The above-described reaction media, with their higher boiling points, usually bring about no pressure increase owing to vapour pressure of solvent in the reaction step, and of`fer consequently additional advantage that the reaction vessel can be designed to withstand merely the pressure of carbon dioxide.
The polycyclic aromatic hydrocarbons which are used in this inventlon lnclude, for exarnple, diaryls, diarylalkanes, trlaryls, triarylalkanes or their hydrogenated compounds or mixtures thereof; as preferred examples, among others, there may be mentioned l-phenyl-1-(2,3-dialkylphenyl)-alkanes, triphenyl, dibenzyl-toluene, hydrogenated triphenyls or mixtures thereof~
and those having a boillng point of not less than 250C
are desirable.
The alkali metal salts of aromatic hydroxy compounds include, for exampleJ potassium phenolate, sodium phenolate or sodium 2-naphtholate.
In the Kolbe-Schmitt reaction process, the complete dehydration of a raw material, an alkali metal salt of aromatic hydroxy compound, constitutes one of the most important problems, and inadequate dehydration of the above-described raw material results in a marked decrease ln reaction yield. The above raw material can be produced ln accordance with the conventional method by the reaction of phenol or 2-naphthol with an alkaline potassium or sodium compound, such as hydroxides, car-bonates and hydrogencarbonates of potassium or sodium,and it is particularly advantageous to dehydrate the resulting alkali metal salt of aromatic hydroxy compound in the presence of the above-mentione reaction medium.
According to this invention, the reaction of an alkali metal salt of aromatic hydroxy compound with carbon dioxide is carried out at a temperature of not lower than 100C, preferably 120 to 300C, particularly 150 to 300C, and\at a carbon dioxide pressure of not higher than 30 kg/cm2 (G), preferably 1 to 15 kg/cm (G), particularly 2 to 10 kg/cm2 (G). The addition amount of the aromatic hydroxy compound is normally not less than 0.05 mole per mole of alkali metal salt of aromatic hydroxy compound, preferably 0.1 to 2 mole. The usage amount of the reaction medium is normally not less than 0.5 part by weight against each part by weight of alkali metal salt of aromatlc hydroxy compound, preferably 0.5 to 10 parts by weight, particularly 1 to 5 parts by weight. The reaction can be conducted either by the batch or contlnuous process, but it is desirable to carry out the reactlon by the continuous process. As the re-action time or the residence time, there can be suitably selected any length of time ranging from several minutes to 15 hours, preferably 10 minutes to 10 hours, particularly 20 minutes to 10 hours.
The finishing treatment can be conducted, for example, by the following procedure. A~ter addition of water to the reaction mixture, the reaction medium layer is separated out, and the dissolved aromatic hydroxy compound can be recovered with a solution of an alkaline potassium or sodium compound as an alkali metal salt of the aromatlc hydroxy compound, which is then subjected to reuse. The separated water layer is ad~usted ln liquid nature with dilute or concentrated sulfuric acid, and the dissolved aromatic hydroxy compound is then extracted with use of toluene or xylene as a reaction medium or organic solvent, as the case may be. The organic solvent layer is washed with a solution of an alkaline potassium or sodium compound to recover it as an alkali metal salt of the aromatic hydroxy compound for reuse as a starting cornpound. Alternatively, the whole amount of the organic solvent layer can be distilled off to separate into the organic solvent and the aromatic hydroxy compound, with the latter being reused as a starting compound. These finishing treatment procedures can be suitably selected.
Industrial Utilizability The present invention can offer variuus advantages as described above under the items tl) through ~9), and is of outstandingly great, industrial value.
Brief Description of the Drawing ~ig. 1 is a schematic flow diagram illustrating the mode of carrying out this invention, wherein the reference numerals 1 and 4 each designates a stirring tank; the numeral 2 a reaction vessel; the numeral 3 a heat exchanger; the numeral 5 a separating tank; the numeral 6 a pH ad~ustment tank; the numeral 7 an ex-tractor; and the numeral 8 an acid precipltation tank,respectively.
~j38~
Preferred Mode of Carryin~ out the Present Invention In a pressure reaction vessel were charged lOOg of sodium phenolate, 35g of phenol and 400g of a mixture of hydrogenated triphenyls, and a reaction was allowed to proceed at 250C and at a carbon dioxide pressure of 7 kg/cm (G) for 20 minutes, with stirring.
The reactlon mixture was cooled and charged into 200 ml of water, followed by separation into the reaction medium layer and the water layer at 60C. The water layer was extracted with 50g of xylene, and the phenol was re-covered with an aqueous potassium hydroxide solution ~rom the reaction medium and extraction medium layers. After recovery of phenol, the water layer was made acid with dilute sulfuric acid to give 80~8g of p-hydroxybenzoic acid (having a purity of 100%), with neither salicylic acid nor isophthalic acid being detected as an isomer.
The yield based on potassium phenolate was 77.3%, and the recovered phenol was 21.8g, with the selectivity being 99.7%.
~XAMPLE 2 In a pressure reaction vessel were charged lOOg of sodium phenolate, 40g of phenol and 400g of 1-phenyl-1-(2,3-dimethylphenyl)-ethane~ and a reaction was allowed to proceed at 170C and at a carbon dioxide pressure of
The polycyclic aromatic hydrocarbons which are used in this inventlon lnclude, for exarnple, diaryls, diarylalkanes, trlaryls, triarylalkanes or their hydrogenated compounds or mixtures thereof; as preferred examples, among others, there may be mentioned l-phenyl-1-(2,3-dialkylphenyl)-alkanes, triphenyl, dibenzyl-toluene, hydrogenated triphenyls or mixtures thereof~
and those having a boillng point of not less than 250C
are desirable.
The alkali metal salts of aromatic hydroxy compounds include, for exampleJ potassium phenolate, sodium phenolate or sodium 2-naphtholate.
In the Kolbe-Schmitt reaction process, the complete dehydration of a raw material, an alkali metal salt of aromatic hydroxy compound, constitutes one of the most important problems, and inadequate dehydration of the above-described raw material results in a marked decrease ln reaction yield. The above raw material can be produced ln accordance with the conventional method by the reaction of phenol or 2-naphthol with an alkaline potassium or sodium compound, such as hydroxides, car-bonates and hydrogencarbonates of potassium or sodium,and it is particularly advantageous to dehydrate the resulting alkali metal salt of aromatic hydroxy compound in the presence of the above-mentione reaction medium.
According to this invention, the reaction of an alkali metal salt of aromatic hydroxy compound with carbon dioxide is carried out at a temperature of not lower than 100C, preferably 120 to 300C, particularly 150 to 300C, and\at a carbon dioxide pressure of not higher than 30 kg/cm2 (G), preferably 1 to 15 kg/cm (G), particularly 2 to 10 kg/cm2 (G). The addition amount of the aromatic hydroxy compound is normally not less than 0.05 mole per mole of alkali metal salt of aromatic hydroxy compound, preferably 0.1 to 2 mole. The usage amount of the reaction medium is normally not less than 0.5 part by weight against each part by weight of alkali metal salt of aromatlc hydroxy compound, preferably 0.5 to 10 parts by weight, particularly 1 to 5 parts by weight. The reaction can be conducted either by the batch or contlnuous process, but it is desirable to carry out the reactlon by the continuous process. As the re-action time or the residence time, there can be suitably selected any length of time ranging from several minutes to 15 hours, preferably 10 minutes to 10 hours, particularly 20 minutes to 10 hours.
The finishing treatment can be conducted, for example, by the following procedure. A~ter addition of water to the reaction mixture, the reaction medium layer is separated out, and the dissolved aromatic hydroxy compound can be recovered with a solution of an alkaline potassium or sodium compound as an alkali metal salt of the aromatlc hydroxy compound, which is then subjected to reuse. The separated water layer is ad~usted ln liquid nature with dilute or concentrated sulfuric acid, and the dissolved aromatic hydroxy compound is then extracted with use of toluene or xylene as a reaction medium or organic solvent, as the case may be. The organic solvent layer is washed with a solution of an alkaline potassium or sodium compound to recover it as an alkali metal salt of the aromatic hydroxy compound for reuse as a starting cornpound. Alternatively, the whole amount of the organic solvent layer can be distilled off to separate into the organic solvent and the aromatic hydroxy compound, with the latter being reused as a starting compound. These finishing treatment procedures can be suitably selected.
Industrial Utilizability The present invention can offer variuus advantages as described above under the items tl) through ~9), and is of outstandingly great, industrial value.
Brief Description of the Drawing ~ig. 1 is a schematic flow diagram illustrating the mode of carrying out this invention, wherein the reference numerals 1 and 4 each designates a stirring tank; the numeral 2 a reaction vessel; the numeral 3 a heat exchanger; the numeral 5 a separating tank; the numeral 6 a pH ad~ustment tank; the numeral 7 an ex-tractor; and the numeral 8 an acid precipltation tank,respectively.
~j38~
Preferred Mode of Carryin~ out the Present Invention In a pressure reaction vessel were charged lOOg of sodium phenolate, 35g of phenol and 400g of a mixture of hydrogenated triphenyls, and a reaction was allowed to proceed at 250C and at a carbon dioxide pressure of 7 kg/cm (G) for 20 minutes, with stirring.
The reactlon mixture was cooled and charged into 200 ml of water, followed by separation into the reaction medium layer and the water layer at 60C. The water layer was extracted with 50g of xylene, and the phenol was re-covered with an aqueous potassium hydroxide solution ~rom the reaction medium and extraction medium layers. After recovery of phenol, the water layer was made acid with dilute sulfuric acid to give 80~8g of p-hydroxybenzoic acid (having a purity of 100%), with neither salicylic acid nor isophthalic acid being detected as an isomer.
The yield based on potassium phenolate was 77.3%, and the recovered phenol was 21.8g, with the selectivity being 99.7%.
~XAMPLE 2 In a pressure reaction vessel were charged lOOg of sodium phenolate, 40g of phenol and 400g of 1-phenyl-1-(2,3-dimethylphenyl)-ethane~ and a reaction was allowed to proceed at 170C and at a carbon dioxide pressure of
10 kg/cm2(G) for 2 hours, with stirring. The reaction mixture was cooled and charged into 500 ml of water, followed by separation into the reaction medium layer and the water layer at 90C. The water layer was ex-tracted with 50g of xylene, and the phenol was recoveredwith an aqueous sodium hydroxlde solution frorn the reaction medium and extraction medium layers. After recovery of phenol, the water layer was made acid with dilute sulfuric acid to give 94.3g of salicylic acld, with neither p-hydroxyhenzoic acid nor isophthalic acld being detected as an isomer. The yield based on sodium phenolate was 90.2%, and the recovered phenol was 57g, ~ ~3 with the selectivity being 98.5%.
In a pressure reactlon vessel were charged 166g of sodium 2-naphtholate, 72g of 2~naphthol and ~98g of hydrogenated triphenyl, and a reaction was allowed to proceed at 260C and at a carbon dioxide pressure of 5 kg/cm (G) for 3 hours, with stirring. The reaction mixture was charged into 800 ml of water~ and the result-ing mixture was adJusted to a pH 5.5 with sulfuric acid, followed by separation into the reaction medlum layer and the water layer at 85C. The 2-naphthol was recovered with an aqueous sodium hydroxide solution from the reac-tion medium layer. After recovery of 2-naphthol, the water layer was adjusted to a pH 2.0 with sulfuric acid at the same temperature9 cooled to 40C and sub~ected to filtration to give 89.3g of 2-hydroxynaphthalene-3-carboxylic acid. The product was found to contain only O. l~o of 2-hydroxynaphthalene-6-carboxylic acid, with no trace of 2 hydroxynaphthalene-l-carboxylic acid. The yield based on sodium 2-naphtholate was 47.5%3 wlth the selectivity being 99.3%.
A finishing treatment was carrled out continu-ously, while employing the facilities as shown in the drawing. On an hourly basis, 83 kg of sodium 2-naphtho-late, 42 kg of 2-naphthol and 166 kg of a mixture of hydrogenated triphenyls were fed to a stirring tank 1, followed by stirring and suspension. The resulting suspension mixture was supplied at a rate of 291 kg/hr to a reaction vessel 2 maintalned at a carbon dioxlde pressure of 6 kg/cm (G), and a reaction was allowed to proceed at 260C, with the residence time being kept at 3 hours. The reaction mixture flowing out of the reaction vessel 2 was cooled with a heat exchanger 3, and mixed with water fed at a rate of ll20 l/hr in a stirring tank 4, and the resulting mixture was regulated at a temperature of 85C and transferred to a separating tank 5, followed by separation into the reaction medium layer and the water layer at 85C. Frorn the upper reaction medium layer, the 2-naphthol was recovered as sodium naphtholate with use of a recovery apparatus (not shown in the drawing). The lower water layer was adJusted in a pH adjusting tank 6 to a pH 5.5 with dilute sulfuric acid and transferred to an extractor 7, where the 2-naphthol and tar were extracted with 2000 llters of xylene. From the xylene layer, there were recovered the xylene and 2-naphthol by use of a vacuum distillation . ~ apparatus (not shown in the drawing). The water layer flowing out of the ~ 7 was transferred to an acid precipitation tank 8y and adjusted to a pH 2.0 with dilute sulfuric acid at 85C to perform acid precipita-tion, whereby there was produced 2-hydroxynaphthalene-3-carboxylic acid at a rate of 44.8 kg/hr. The yield based on sodium 2-naphtholate was 47.7%, and 2 naphthol was recovered at a rate of 37.3 kg/hr, with the selectivity being 99.4%.
In a pressure reaction vessel were charged lOOg of potassium phenolate, 35g of phenol and 500g of a mixture of hydrogenated triphenyls, and a reaction was allowed to proceed at 250C and at a carbon dioxide pres-sure of 7 kg/cm2(G) for 20 mlnutes, with stirring. Thereaction mixture was cooled and charged into 200 ml of water, ~ollowed by separation into the reaction medium layer and the water layer at 60C. The water layer was made acid with dilute sulfuric acid to give 81.6g of p-hydroxybenzoic acid (having a purity of 99%). The yieldbased on potassium phenolate was 77.3%, and the recovered potassium phenolate was 21.0g, with the selectivity being 99.7%.
In a pressure reactlon vessel were charged 166g of sodium 2-naphtholate, 72g of 2~naphthol and ~98g of hydrogenated triphenyl, and a reaction was allowed to proceed at 260C and at a carbon dioxide pressure of 5 kg/cm (G) for 3 hours, with stirring. The reaction mixture was charged into 800 ml of water~ and the result-ing mixture was adJusted to a pH 5.5 with sulfuric acid, followed by separation into the reaction medlum layer and the water layer at 85C. The 2-naphthol was recovered with an aqueous sodium hydroxide solution from the reac-tion medium layer. After recovery of 2-naphthol, the water layer was adjusted to a pH 2.0 with sulfuric acid at the same temperature9 cooled to 40C and sub~ected to filtration to give 89.3g of 2-hydroxynaphthalene-3-carboxylic acid. The product was found to contain only O. l~o of 2-hydroxynaphthalene-6-carboxylic acid, with no trace of 2 hydroxynaphthalene-l-carboxylic acid. The yield based on sodium 2-naphtholate was 47.5%3 wlth the selectivity being 99.3%.
A finishing treatment was carrled out continu-ously, while employing the facilities as shown in the drawing. On an hourly basis, 83 kg of sodium 2-naphtho-late, 42 kg of 2-naphthol and 166 kg of a mixture of hydrogenated triphenyls were fed to a stirring tank 1, followed by stirring and suspension. The resulting suspension mixture was supplied at a rate of 291 kg/hr to a reaction vessel 2 maintalned at a carbon dioxlde pressure of 6 kg/cm (G), and a reaction was allowed to proceed at 260C, with the residence time being kept at 3 hours. The reaction mixture flowing out of the reaction vessel 2 was cooled with a heat exchanger 3, and mixed with water fed at a rate of ll20 l/hr in a stirring tank 4, and the resulting mixture was regulated at a temperature of 85C and transferred to a separating tank 5, followed by separation into the reaction medium layer and the water layer at 85C. Frorn the upper reaction medium layer, the 2-naphthol was recovered as sodium naphtholate with use of a recovery apparatus (not shown in the drawing). The lower water layer was adJusted in a pH adjusting tank 6 to a pH 5.5 with dilute sulfuric acid and transferred to an extractor 7, where the 2-naphthol and tar were extracted with 2000 llters of xylene. From the xylene layer, there were recovered the xylene and 2-naphthol by use of a vacuum distillation . ~ apparatus (not shown in the drawing). The water layer flowing out of the ~ 7 was transferred to an acid precipitation tank 8y and adjusted to a pH 2.0 with dilute sulfuric acid at 85C to perform acid precipita-tion, whereby there was produced 2-hydroxynaphthalene-3-carboxylic acid at a rate of 44.8 kg/hr. The yield based on sodium 2-naphtholate was 47.7%, and 2 naphthol was recovered at a rate of 37.3 kg/hr, with the selectivity being 99.4%.
In a pressure reaction vessel were charged lOOg of potassium phenolate, 35g of phenol and 500g of a mixture of hydrogenated triphenyls, and a reaction was allowed to proceed at 250C and at a carbon dioxide pres-sure of 7 kg/cm2(G) for 20 mlnutes, with stirring. Thereaction mixture was cooled and charged into 200 ml of water, ~ollowed by separation into the reaction medium layer and the water layer at 60C. The water layer was made acid with dilute sulfuric acid to give 81.6g of p-hydroxybenzoic acid (having a purity of 99%). The yieldbased on potassium phenolate was 77.3%, and the recovered potassium phenolate was 21.0g, with the selectivity being 99.7%.
Claims (6)
1. A process for selectively producing an aromatic hydroxycarboxylic cold, characterized in that the said process comprises subjecting a liquid mixture consisting of a polycyclic aromatic hydrocarbon, an alkali metal salt of an aromatic hydroxy compound and a free aromatic hydroxy compound to a reaction with carbon dioxide.
2. The process of Claim 1 wherein the aromatic hydrocarbon is selected from the group consisting of diaryls, diarylalkanes, triaryls, triarylalkanes and their hydrogenated products and mixtures thereof.
3. The process of Claim 1 or 2 wherein the alkali metal salt of an aromatic hydroxy compound is sodium phenolate, potassium phenolate or sodium 2-naphtholate, and the free aromatic hydroxy compound is phenol or 2-naphthol.
4. The process of Claim 1 or 2 wherein the reaction of an aromatic hydroxy compound with an alkaline potassium or sodium compound and/or the dehydration of the alkali metal salt of an aromatic hydroxy compound to be obtained by the said reaction are carried out continuously.
5. The process of Claim 1 or 2 wherein after conclusion of the reaction, the alkali metal salt of an aromatic hydroxy compound which is present as dissolved in the separated reaction medium is recovered for reuse.
6. The process of Claim 1 or 2 wherein after conclusion of the reaction, the water layer separated through the addition of water is subjected to a pH
adjustment and the dissolved aromatic hydroxy compound is extracted with a solvent and recovered for reuse as an alkali metal salt of the aromatic hydroxy compound after the action of an alkaline potassium or sodium compound.
adjustment and the dissolved aromatic hydroxy compound is extracted with a solvent and recovered for reuse as an alkali metal salt of the aromatic hydroxy compound after the action of an alkaline potassium or sodium compound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000508469A CA1263868A (en) | 1986-05-06 | 1986-05-06 | Process for producing aromatic hydroxycarboxylic acids |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000508469A CA1263868A (en) | 1986-05-06 | 1986-05-06 | Process for producing aromatic hydroxycarboxylic acids |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1263868A true CA1263868A (en) | 1989-12-12 |
Family
ID=4133068
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000508469A Expired CA1263868A (en) | 1986-05-06 | 1986-05-06 | Process for producing aromatic hydroxycarboxylic acids |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1263868A (en) |
-
1986
- 1986-05-06 CA CA000508469A patent/CA1263868A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100282074B1 (en) | Manufacturing method of 2,6-naphthalenedicarboxylic acid | |
| US4239913A (en) | Process for preparing 2-hydroxynaphthalenecarboxylic acids | |
| US4287357A (en) | Process for the production of 6-hydroxy-2-naphthoic acid | |
| US4780567A (en) | Process for producing aromatic hydroxycarboxylic acids | |
| KR870000245B1 (en) | Process for the preparation of 2-hydroxy naphthalene-6-carboxylic acid | |
| US4329494A (en) | Recycling techniques in the production of 6-hydroxy-2-naphthoic acid | |
| CA1263868A (en) | Process for producing aromatic hydroxycarboxylic acids | |
| EP0254596B1 (en) | Manufacturing method for 2-hydroxynaphtalene-6-carboxylic acid | |
| KR870000202B1 (en) | A process for preparing 2-hydroxynaphthalene-6-carboxylic acid selectively | |
| EP0066205B1 (en) | Process for preparation of 2-hydroxynaphthalene-3-carboxylic acid | |
| US4952721A (en) | Process for oxidizing esters of methyl-substituted phenol compounds to aromatic carboxylic acids | |
| US3551300A (en) | By-water dissolution,steam distillation,activated carbon and cation exchange treatment and crystallization | |
| US2978514A (en) | Separation of pentaerythritol and dipentaerythritol from solution | |
| US4345094A (en) | Process for the production of 6-hydroxy-2-naphthoic acid | |
| US4337355A (en) | Process for preparing 4-hydroxyphenylacetic acid | |
| JP4126729B2 (en) | Method for producing phthalides | |
| US4814521A (en) | Process for producing 2,6-dihydroxynaphthalene and 2,6-diacetoxynaphthalene | |
| US3247246A (en) | Cyclic process for production of terephthalic acid | |
| US5354876A (en) | Preparation and purification of 1-amino-2-phenoxy-4-hydroxyanthraquinone | |
| US4962274A (en) | Process for separating alkyl-substituted naphthalene derivatives using clathrate complexes | |
| US5081263A (en) | Dioxane adducts of aromatic meta- or para-hydroxy-carboxlic acids | |
| US4831168A (en) | Process for preparing 2-hydroxydibenzofuran-3-carboxylic acid and alkali metal salts thereof | |
| JPH0526774B2 (en) | ||
| US6441225B1 (en) | Purification of aromatic diacids | |
| WO1999018060A1 (en) | Process for the purification of naphthalenedicarboxylic acid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed | ||
| MKEC | Expiry (correction) |
Effective date: 20121205 |