DE1052974B - Process for the preparation of aromatic carboxylic acids, their salts or esters - Google Patents

Description

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FEDERAL REPUBLIC OF GERMANY

GERMAN

kl. 12 ο 14

INTERNAT. KL. C 07 C

PATENT OFFICE

C07 C 69/76

EXPLAINING EDITORIAL 1052 974

B 37852 IVb / 12 ο

REGISTRATION DATE: NOVEMBER 9, 1955

NOTICE
THE REGISTRATION
AND ISSUE OF THE
EXPLORATION PAPER: 1 9 M AR Z 1 9 5 9

The subject of patent 1 033 654 is a process for the production of aromatic carboxylic acids, their esters or their salts, in which halogenated hydrocarbons are used with formates of the metals the I. and or or II. main group of the periodic table and / or ammonium increased temperature and under increased pressure.

It has now been found that aromatic carboxylic acids, their salts or esters are also obtained if instead of the formates of the metals mentioned in the main patent and / or ammonium, the Hydroxides of these metals and / or ammonium hydroxide and carbon oxide are used. To implement one uses the hydroxides, of which in addition to ammonium hydroxide, especially sodium, potassium, Magnesium, calcium, barium or strontium hydroxide comes into consideration, in at least one such an amount that for every halogen atom of the halogenated hydrocarbon there is one hydroxyl group of the There is no metal hydroxide, for example when using 1 mole of dichlorobenzene as the starting halogenated hydrocarbon 2 moles of ammonium hydroxide or alkali metal hydroxide or 1 mole of alkaline earth metal hydroxide. However, it is advantageous to use about 1.5 bis 3 times, expediently twice this amount, the salts then being the reaction products Carboxylic acid can be obtained. It is also possible to use part of the amount of hydroxide, e.g. B. about a tenth up to eight tenths, through carbonates of the metals of T. and / or II. main group of the periodic System or to replace it with ammonium carbonate.

The implementation of the hydroxyl compound with carbon oxide and those described in the main patent Halocarbons takes place under the conditions specified there, so preferably with one Temperature between about 100 and 400 ° C, in particular at 170 to 350 ° C, and under a pressure of 5 to 300 at, whereby this is adjusted by pressing in carbon oxide and maintained as long as a decrease in pressure can still be determined. Solvents such as hydrocarbons, e.g. B. benzene, gasoline and the like can also be used. Working in the presence is particularly useful of water, aqueous alcohols or anhydrous alcohols, the esters being obtained in the latter case will.

As in the procedure of the main patent, the implementation can be accelerated by adding catalysts are, the compounds mentioned in the main patent as catalysts, in particular so metal carbonyl compounds come into consideration, both as such and in the form of their Components can be used. Furthermore, a method of production

of aromatic carboxylic acids,

their salts or esters

Addendum to patent 1,033,654

Applicant:

Aniline & Soda Factory in Baden

Corporation,

Ludwigshafen / Rhine

Dr. Hugo Kröper, Heidelberg,

Dr. Friedrich Wirth, Ludwigshafen / Rhein-Oggersheim,

and Dr. Otto Hermann Huchler, Ludwigshafen / Rhine,

have been named as inventors

Finely divided copper or silver as well as halides of copper, silver, nickel come as catalysts, Cobalt and iron into consideration.

The presence of the substances that accelerate the reaction makes it more watery or alcoholic when working Solution, however, necessary to apply the hydroxyl compound in not too low a concentration, since otherwise the reaction process will be delayed or even prevented. In this case it is useful to use the Hydroxides in a concentration of at least 10%, advantageously 50% and higher, to use special To achieve advantages over working without a catalyst. The procedure can be both be carried out continuously as well as discontinuously, whereby it is not necessary in corrosion-resistant Apparatus to work.

example 1

147 parts of p-dichlorobenzene, 80 parts of sodium hydroxide and 36 parts of water are poured in and after 120 at Carbon dioxide heated to 310 ° C. The pressure rises to 250 at and is reduced when the pressure decreases Repressing of carbon monoxide kept constant for 10 hours. The powdery one removed from the autoclave The reaction product is extracted with water and 14 parts of terephthalic acid are extracted from the aqueous filtrate precipitated by acidification with mineral acid. The residue not dissolved in water is with benzene extracted, with 59 parts of unreacted p-di-

Claims (2)

chlorobenzene go into solution and 65 parts of terephthalic acid remain undissolved. The yield is 79% of theory (degree of conversion 59.9%). Example 2 147 parts of p-dichlorobenzene, 160 parts of sodium hydroxide and 108 parts of water with 10 parts of nickel carbonyl are introduced into a roller autoclave. After pressing in 120 atmospheres of carbon oxide, the mixture is heated to 310 ° C. and the pressure of 250 atmospheres which is established is kept constant for 10 hours by forcing in more carbon oxide. 119 parts of terephthalic acid are precipitated from the aqueous extract of the reaction product by acidification. The undissolved residue still contains 14 parts of unreacted p-dichlorobenzene. The yield of terephthalic acid is 79% of theory (conversion 90.5%). If one works under otherwise identical conditions using 1440 parts of water, terephthalic acid is obtained in a yield of only 1 part. EXAMPLE 3 74 parts of p-dichlorobenzene, 80 parts of sodium hydroxide and 36 parts of water are poured into a copper-lined shaking autoclave and, after 120 atmospheres of carbon oxide have been injected, the mixture is shaken at 310 ° C. for 20 hours. The reaction product is extracted with water and the aqueous solution is acidified, 47 parts of terephthalic acid precipitating out as an insoluble precipitate. 10 parts of terephthalic acid and 2 parts of unreacted p-dichlorobenzene are obtained from the water-insoluble residue. The yield of terephthalic acid is 68.8% of theory (conversion 98.8%). Example 4 147 parts of p-dichlorobenzene, 40 parts of sodium hydroxide, 160 parts of calcined soda and 108 parts of water are introduced into a roller autoclave. After injecting 100 atm of carbon oxide, the mixture is heated to 310 ° C. and kept at this temperature for 20 hours. The reaction product is extracted with water and the aqueous solution is acidified. 91 parts of terephthalic acid are obtained. 2 parts of terephthalic acid and 1 part of unreacted p-dichlorobenzene are obtained from the residue, which is insoluble in water. The conversion is practically complete. The terephthalic acid yield is 56% of theory. ~ ^ Example 5 147 parts of p-dichlorobenzene, 160 parts of sodium hydroxide, 100 parts of water, 150 parts of isopropyl alcohol and 3 parts of nickel carbonyl are introduced into a roller autoclave. After pressing in 170 atmospheres of carbon oxide, the vessel is heated to 340 ° C. The pressure rises to 420 at and, if the pressure drops, it is set again to the starting pressure of 420 at by injecting more carbon dioxide every hour. After 3 hours, the autoclave is allowed to cool and it is relaxed. The reaction product obtained is acidified with mineral acid. After separation and drying, 150 parts of terephthalic acid are obtained. With complete conversion of p-dichlorobenzene, the yield is 90% of theory. Example 6 147 parts of p-dichlorobenzene, 80 parts of sodium hydroxide, 600 parts of methanol and 3 parts of nickel powder are placed in an autoclave. After 125 atmospheres of carbon dioxide have been injected, the vessel is heated and held at 360 ° C. for 2 hours. The pressure increases to 400 at. The solid fraction of the reaction product is separated off from the methanolic mother liquor and extracted with water. 146 parts of crude dimethyl terephthalate remain as residue. The ester has a melting point of 140 to 142 ° C. By working up the methanolic mother liquor, a further 12 g of ester are obtained. The total yield of dimethyl terephthalate is thus 81.4% of theory. 14 parts (= 8.4% of theory) of terephthalic acid are precipitated from the aqueous extraction solution by acidification with hydrochloric acid. EXAMPLE 7 147 parts of p-dichlorobenzene, 138 parts of calcium hydroxide, 100 parts of water and 300 parts of isobutyl alcohol and 3 parts of nickel powder are placed in a pressure vessel, the vessel is closed and 180 atmospheres of carbon oxide are injected. The vessel is then heated to 350 ° C., the pressure increasing to 475 atm. After the heating has continued for 3 hours at 350 ° C., the vessel is allowed to cool and it is relaxed. The reaction product is taken up in water and filtered. 132.3 parts of pure terephthalic acid are obtained from the solid filter cake by extracting it with concentrated soda solution and acidifying the extract with hydrochloric acid. The yield is 79.7% Pat ε ν τ λ ν s ρ r, ü c ιι ε: 1. Process for the preparation of aromatic carboxylic acids, their salts or esters by Reaction of halogenated hydrocarbons with formic acid salts, their cation by a Metal of the I. main group of the periodic system and / or ammonium formed is, at elevated temperature and under elevated pressure according to patent 1 033 654, characterized in, that instead of the formates carbon monoxide and the hydroxides of the metals of I. and or or II. main group of the periodic system or ammonium hydroxide is used. 2. The method according to claim 1, characterized in that the metal hydroxides or ammonium hydroxide in an at least 10% aqueous or alcoholic solution. Considered publications:
U.S. Patent Nos. 2,565,462, 2,640,071. © 809 770/482 3. 59