MXPA96006201A - Procedure to recover the decobalite carbonils employed as catalysts in the preparation of n-acil-alpha-amino acids poramidocarbonilac - Google Patents

Abstract

The present invention relates to a process for recovering the cobalt carbonyls used as a catalyst in the preparation of N-acyl-alpha-amino acids by amidocarbonylation, the object of the present invention is a process for recovering the used carbonyl-cobalt catalyst, according to which a water-soluble cobalt salt is first prepared by adding acid, which is then precipitated as cobalt hydroxide, then this cobalt hydroxide is reacted with the N-acyl-alpha-amino acid, for which The carbonyl-cobalt catalyst is provided, and the cobalt-containing fusion obtained is transformed into the carbonyl-cobalt catalyst, in the presence of a mixture formed by carbon monoxide and hydrogen.

Description

PORA PROCEDURE TO RECOVER THE COBALT CARBONILS EMPLOYED AS CATALYSTS IN THE PREPARATION OF N-ACIL-tt- AMINOACTDOS BY AMIDOCARl? ONILACTON.

The carboxylic amide carbon amides in the presence of aldehydes and carbon monoxide or synthesis gas are added by arnidocarbomination to obtain N-acyl derivatives 1 -of-a-i-acids. This reaction is carried out in the presence of carbonyl-cobalt compounds as catalysts. If fatty acid amides are used as an arnide component and formaldehyde as an aldehydic component, the procedure allows to investigate the class of N-acyl sarcosmae, substances used in the industry with surfactants, soaps and emulsifiers. An essential part of the preparation process consists of establishing a catalyst cycle, that is, a procedure to separate the used catalyst from the manufactured product, regenerate it and re-introduce it in the process. For reasons of cost and to avoid contamination of the environment with cobalt compounds, a process is required to recover the carbom 1 -cobalt catalyst that is as complete, simple and economical as possible. The Japanese invention document No. 54-112816 discloses a process for preparing dialkylmalonic esters by fication of an alkyl-rnonohaloacetic acid with a short-chain aliphatic alcohol and carbon monoxide, in the presence of a carboml-cobalt catalyst and a basic compound. After this, the decomposition of the catalyst is followed by adding an aqueous solution of an inorganic acid, e.g. ex. sulfuric acid. The water-soluble cobalt salt is precipitated from the aqueous phase thus obtained and separated by the addition of alkaline hydroxide, μ.e., sodium hydroxide, co or cobalt hydroxide, which is soluble in water. The precipitate of cobalt hydroxide is washed thoroughly and the water is removed. Finally, the cobalt hydroxide is transformed into the corresponding carbonyl bismuth cobalt by addition to carbon dioxide or carbon monoxide / hydrogen in the presence of an organic solvent, e.g. a hydrocarbon or a suitable alcohol for esterification. The carboml-cobalt catalyst obtained in this way is reused in the fication. In the Japanese document of invention n ° 57-183749 a process of preparation of t-amine- (3-hydroxy butanoic acid, by which in a first stage of carbonylation react epichlorhydrin, carbon monoxide, a basic compound is described and an alcohol giving t-am? no-β-hydroxyl butanoic acid In the next step the carboml-cobalt catalyst is decomposed by adding mineral acid, eg sulfuric acid, and oxygen to the The reaction solution resulting from the previous step is then removed, the alcohol present in the reaction solution is removed and then by the addition of water a two-phase system is formed, separated in an aqueous phase containing the water-soluble cobalt salt and in the an organic phase containing the t-ami non-β-hydroxy-butanoic acid The carbonyl-cobalt catalyst is recovered by adding alkali metal hydroxide to the aqueous phase The precipitate of alkali metal hydroxide to the aqueous phase The resulting cobalt hydroxide is separated by filtration, washed and then dehydrated. Finally, by reacting the cobalt hydroxide with carbon monoxide and hydrogen, the carbomylcobalt catalyst is again obtained. Japanese Invention Document No. 58-19B441 relates to a process for preparing malonic diesters, whereby in a first carbonylation step the reaction of onocloroacetic acid, carbon monoxide, sodium carbonate and an alcohol in the presence of a carbonyl-cobalt catalyst dissolved in alcohol or acetone. In the next stage of the process, the carbonyl-cobalt catalyst is decomposed by adding sulfuric acid and oxygen to the reaction solution obtained above. The excess alcohol or acetone is removed by distillation. Water is added to the concentrated reaction solution and the resulting aqueous and organic phases are processed separately, obtaining the malonic diester by distillation from the organic phase. The aqueous phase containing the cobalt sulphate is made alkaline by adding alkali metal hydroxide and the resulting precipitate of cobalt hydroxide is washed, filtered and the water present is removed, eg by spray drying, finally the hydroxide The dry cobalt is converted into the corresponding carbon-1-carbon catalyst solution by reaction with carbon monoxide and hydrogen in alcohol or acetone. The object of EP-fl-0 343 042 is a process for preparing dialkylrnalonic esters by carbonylation of alkyl esters of chloroacetic acid in the presence of a carbonyl-cobalt catalyst. The recovery of the carboml-cobalt catalyst used takes place in several stages, first preparing by acid addition a water-soluble cobalt salt. In the next step, this cobalt salt is converted into the salt of a fatty acid, eg oleic, palmitic or stearic. From this fatty acid salt the desired carboml-cobalt catalyst is obtained by reaction with carbon monoxide and hydrogen. For the reasons set forth below, the aforementioned processes, corresponding to the current technical level, are not suitable for the recovery of the cobalt carbonyls used as catalysts in the preparation of N-acyl a-amino acids by amidocarbonylation. The object of the present invention is to provide a process for recovering the cobalt carbonyls used as catalysts in the preparation of N-acyl-a-ammo acids by amidocarbonylation. In the case of the N-acyl-a-arninoacids, a process of this type presents the following technical difficulties. The reaction products of the arnidocarbonate, especially the N-acylsarcosines already mentioned, are not volatile and, therefore, can not be removed from the reaction solution by distillation. It is also not possible to separate in the pure state, because they are destroyed by heating the reactant solution, ie in the presence of N-acyl-cx ~ amino acids. It should also be borne in mind that after the reaction, the 1-cobalt carboni catalysts used in the incarbonization still remain partially active, so a number of different cobalt carbonyls must be available for the recovery process. Due to the mild reaction conditions during the carbonylation step of the amidocarbonylation, the carboml-cobalt catalysts can not be prepared from the Co (TI) salts, e.g. ex. Cobalt acetate, oxide and cobalt hydroxide, but must be manufactured in a previous stage to be used in the next stage of carbonylation. The object of the present invention is a process for recovering the cobalt carbonyls used as catalysts in the preparation of N-acyl-a-amino acids, especially N-acyl sarcosines, by a -docarbonylation, which comprises the following steps: of aqueous solution of hydrogen peroxide or of aqueous solution of hydrogen peroxide and sulfuric acid to the reaction solution formed after the preparation of the N-acyl-of-amino acid, subsequent separation of the aqueous phase, containing the cobalt sulphate (II) ), of the non-aqueous phase, followed by the removal of excess hydrogen peroxide in the aqueous phase resulting from the previous stage-, then addition of alkali metal hydroxide to the aqueous phase of the previous stage, followed by the previous stage , followed by separation of the precipitate of cobalt hydroxide obtained, washing with water and preparation of a cobalt melt from the washed cobalt hydroxide and of the N-acyl-a-amino acid, for which preparation the carbonyl-cobalt catalyst is provided and finally, transformation of the cobalt melt thus obtained, in the presence of a mixture of car bonbon oxide and hydrogen at a temperature of 70 up to 250 ° C and a pressure of 50 to 250 bar, in the carbonyl-cobalt catalyst. In the process of the present invention it is necessary to recover the carbonyl-cobalt catalysts, especially Coa (CO) a and HCo (CO). ", Used in the ardocarbonylation. The starting point of the process is the reaction solution formed after the preparation of the N-acyl-a-arnino acid, especially the N-acyl sarconine. The process of the present invention is especially suitable for reactive solutions such as those resulting from the preparation process of N-acyl-a-arnino acids described in European Patent Application No. 95 106 329.6 (EP-FL-0 680). 948). In the first stage of the process, the addition of an aqueous solution of hydrogen peroxide to this reactive solution takes place. In general, if the ardocarbonylation is carried out in sulfuric acid solution, the addition of more sulfuric acid, preferably diluted, is not necessary to form cobalt salts soluble in water. The aqueous phase thus obtained, which contains water-soluble Co (II) sulfate, is separated from the non-aqueous phase. By repeated addition in water or aqueous solution of sulfuric acid to the non-aqueous phase, which bears the N-acyl-or-arnino acid, if necessary in extraction apparatus, e.g. mixers-decanters, centrifugal extractor and countercurrent extraction column, the cobalt content in this non-aqueous phase can be further reduced. It has been shown that under the conditions of precipitation, the presence of a certain amount of hydrogen peroxide produces the formation of aqueous cobalt (III) hydroxide, stable in an alkaline medium, which precipitates very finely and is difficult to filter. The excess hydrogen peroxide is removed, as usual, by heating the aqueous phase, preferably up to the boiling temperature. Technically, it is advantageous to heat the aqueous phase under reduced pressure, at the same time separating the solvent by distillation. Once the excess hydrogen peroxide is removed, alkali metal hydroxide, preferably sodium and / or potassium hydroxide, is added to the aqueous phase, obtaining a precipitate of water-insoluble cobalt hydroxide. Preferably, 30% by weight aqueous solution of alkali metal hydroxide is added. The pH value of the aqueous phase after adding the alkali metal hydroxide should be approximately 12, preferably. During the precipitation it is convenient that the cobalt sulphate solution does not have a concentration greater than 2% by weight, otherwise, the precipitation in the form of cobalt hydroxide is not complete. This precipitate of cobalt hydroxide which is more soluble in water is separated from the aqueous phase. The precipitate generally contains between 8 and 12% by weight of cobalt, about 70% by weight of water (determined by vacuum drying at 90 ° C) and about 10% by weight of sulphate salts. Then, the water-soluble salts are removed by washing with water, without this implying a significant extraction of cobalt ions by the washing water. For the process of the present invention it is convenient that the cobalt hydroxide precipitate is largely free of salts. In the next stage of the process, a cobalt melt is prepared with the precipitate of washed cobalt hydroxide and in N-acyl-a-amino acid, in which preparation the carbonyl-cobalt catalyst is used. In this process, the washed cobalt hydroxide is preferably incorporated into the N-acyl-a-arninoaci or molten. Preferably, they are derivatives of the N-acyl sarcosms, especially sarcosms of fatty acids, such as oleyl- or lauroyl sarcosine. The preparation of the cobalt melt is carried out by the reaction of cobalt hydroxide, preferably with a water content of 55-75% by weight, with the N-acyl-or-amino acid in a molar ratio of 1: 2-5, all 1: 3-4. The reaction of cobalt hydroxide with N-acyl-a-amino acid usually takes place between 100 and 120 ° C, and agglomerates of cobalt hydroxide can form and only react slowly. This difficulty is overcome by adding catalytic amounts of acetic acid to the cobalt hydroxide in suspension. By the reaction of cobalt hydroxide with the N-acyl-a-amino acid a cobalt melt is prepared from which the water can be completely removed by treatment under reduced pressure and elevated temperature, without obtaining dried cobalt salts. The conversion of the cobalt melt thus obtained into the carbonyl-cobalt catalyst is preferably carried out in a polar aprotic solvent, which can be used as such for the following amidocarbonylation. Particularly suitable solvents have been tetrahydrofuran, glycolidene ether, tertiary butyl ether, diglycoline + light, dimethylformamide, dirnethylacetamide, butyl acetate and acetonitrile. Especially used are tetrahydrofuran, tert-butylmethylether and glycololdylether. For this purpose, the cobalt melt is reacted with carbon monoxide or a mixture of carbon monoxide and hydrogen, the so-called synthesis gas, at a temperature of 70 to 250 ° C and a pressure of 50 to 250 bar, preferably 60 to 200 bar, especially between 80 and 100 bar. The composition of the carbon monoxide / hydrogen mixture is preferably from 4: 1 to 1: 4. The carbomylcobalt catalyst formed can be used without limitations in the amidocarbonylation.

FTFMPI O DF PREPARATION Recovery of the carbo-cobalt catalyst used to prepare lauroyl sarcosine by amidocarbonate 100 ml of a solution of cobalt sulphate resulting from the preparation of the organic phase, which contains sulfuric acid and still remains of hydrogen peroxide, with 1.56% by weight of cobalt, it is first heated to boiling temperature to remove the hydrogen peroxide. After cooling this acid solution, the pH is adjusted to 12 by adding 12 rnl of a 30% solution 3n weight of sodium hydroxide, obtaining a bluish green precipitate of cobalt hydroxide with high water content (20.0 g). The precipitate is aspirated through a frit G and washed with 200 rnl water to remove the sulfate. The highly water-laden cobalt hydroxide (18.2 g) is suspended in 29.0 g of lauroyl sarcosine (equivalent to about 4 moles) and the viscous suspension is heated under stirring at 120 ° C. The cobalt hydroxide dissolves taking a violet color. After the complete dissolution of the cobalt hydroxide precipitate, the water is removed from the cobalt melt in the rotary evaporator (water bath temperature: 95 ° C, pressure: 50 inbar). The residue (29.7 g) is then dissolved in 30 ml of methyl t-butyle + er and subjected to carbonylation in the steel autoclave at a pressure of 120 bar with synthesis gas (CO: H3 = 2 ratio). :1). The reaction starts between 70 and 90 ° C. The carbonyl-cobalt catalyst that is formed can be used without limitations to obtain lauroi-1-sarcosm by amidocarbonylation.

Claims (13)

NOVEPRD PE LR INVENTION CLAIMS

1. Process for recovering Cobalt carbonyls used as catalysts in the preparation of N-acyl-a-arnino acids, especially N-acyl sarcosms, by amidocarbomination, comprising the following steps: addition of aqueous solution of hydroxyrene peroxide or aqueous solution of hydrogen peroxide and sulfuric acid to the reaction solution formed after the preparation of N-acyl-a-amino non-acid, subsequent separation of the aqueous phase, containing the cobalt (II) sulphate, from the non-aqueous phase, followed by the binding of the excess hydrogen peroxide in the aqueous phase resulting from the previous step, then addition of alkali metal hydrogen to the aqueous phase of the previous step, followed by the separation of the precipitate of cobalt hydroxide obtained, washed with water; and preparing a cobalt melt from the washed cobalt hydroxide and the non-acidic N-acyl-a-arnide, for the preparation of which the carbonyl-cobalt catalyst is provided; and finally, transformation of the cobalt melt thus obtained, in the presence of a mixture of carbon monoxide and hydrogen at a temperature of 70 to 250 ° C and a pressure of 50 to 250 bar, in the carboml-cobalt catalyst.

2. Process according to claim 1, characterized in that the aqueous phase is heated, preferably up to the boiling temperature, to remove the excess hydrogen peroxide.

3. Process according to claim 1 or 2, characterized in that sodium or potassium hydroxide or a mixture of both is added to the aqueous phase. Process according to one of Claims 1 to 3, characterized in that 30% by weight aqueous alkali metal hydroxide solution is added to the aqueous phase. Method according to one of claims 1 to 4, characterized in that upon completion of the addition of the alkali metal hydroxide, the pH of the aqueous phase is approximately 12. The method according to one of claims 1 to 5, characterized in that To prepare the cobalt fusion, the washed cobalt hydroxide is incorporated into the N-acyl-molten amino acid. Process according to one of Claims 1 to 6, characterized in that the washed cobalt hydroxide contains 65-75% by weight of water. 8. Process according to one of claims 1 to 7, characterized in that an N-acyl sarcosine, preferably a fatty acid sarcosine, is used as the N-acyl aminino acid. Method according to one of claims 1 to 8, characterized in that, in order to prepare the cobalt melt, the molar ratio between cobalt hydroxide and N-acyl-a-amino acid is from 1: 2-5 to 1: 3-

4. . 10. Process according to one of claims 1 to 9, characterized in that the water present in the cobalt melt is removed before it is converted into the carboml-cobalt catalyst. 11. Process according to one of claims 1 to 10, characterized in that the conversion of the cobalt melt to the carboml-cobalt catalyst is carried out in a polar aprotic solvent. Method according to one of claims 1 to 11, characterized in that the conversion of the cobalt melt into the carboml-cobalt catalyst takes place at a pressure of 60 to 200 bar, preferably 80 to 180 bar-. 13. Process according to one of claims 1 to 1, characterized in that for the anomerization of the cobalt melt in the carboml-cobalt catalyst, the composition of the carbon monoxide / hydrogen mixture is: 1 to 1: 4. .