RU2237056C1 - Method for preparing succinic acid - Google Patents

Abstract

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for preparing synthetic succinic acid that exhibits biological activity related with that of succinic acid prepared by pyrolysis of amber and using as a drug or nutrient biologically active supplement. Method is carried out by hydrogenation of maleic anhydride, maleic or fumaric acid in an aqueous medium in the presence of palladium-iron catalyst. Catalyst represents palladium complex compounds and iron water-soluble compounds applied on carbon carrier by adsorption. Process is carried out in the presence of palladium-iron catalyst prepared in using palladium complex compounds and succinic, maleic or fumaric acid as palladium complex compounds and their adsorption on carbon carrier in the formation point. Prepared succinic acid has biological properties related with properties of "natural" acid: diuretic, cardiotonic, anti-arrhythmic, antihypoxic and adaptogenic effects.

EFFECT: improved preparing method.

2 cl, 3 tbl, 6 dwg, 18 ex

Description

The invention relates to a method for producing biologically active succinic acid (UC) by hydrogenation of maleic anhydride (MA), maleic or fumaric acids (MK or FC) in an aqueous medium in the presence of heterogeneous catalysts.

Succinic acid is a natural metabolite of living organisms, including person. This is one of the acids involved in the Krebs cycle, providing energy metabolism at the cellular level.

The therapeutic properties of UC have been known for a long time, its use has a positive effect in the treatment of many diseases, including acute respiratory, nervous, cardiac, etc. UC protects against the effects of radioactive radiation, helps to eliminate toxins from the body, reduces the craving for alcohol, etc.

However, studies have shown that samples of “natural” (obtained from amber) and UC synthesized by various methods are not identical in biological activity [E.I. Mayevsky, M.N. Kondrashova, M.L. Teacher and other Biological activity of succinic acid, "Medicina Altera", December 2001, S. 11].

Known methods for producing UC and its salts by hydrogenation of MA, MK and FC in the presence of traditional hydrogenation catalysts based on metals of group VIII of the Periodic system (Ni, Ru, Rh, Pd, Pt) in the form of black, oxide, in skeletal form and deposited on substrates [ U.S. Patent 2,198,153; German patent 1259869; Japanese Application 69-29246; Japanese Application 61-204149].

The most effective way to obtain UC of high purity is RF Patent 2129540, publ. 07.24.99 (decl. 04/01/97), which was chosen as the closest analogue.

According to this method, UC or its salts are obtained by hydrogenation of MA or MK (FC) or the corresponding salts of MK in water in the presence of a heterogeneous catalyst. This catalyst contains complex water-soluble compounds of palladium and iron at a mass ratio of palladium: iron (in terms of metal), equal to from 1: 0.1 to 1: 6, deposited from pre-prepared solutions on a carbon carrier, and use as a complex compound of palladium polychlorohydroxocomplexes of palladium.

The productivity of the process of synthesis of succinic acid, that is, removal of the target product from a unit mass of palladium per unit time, is 308-546 g UC / g Pd · min, palladium consumption is 2.9 · 10 ^-5 -0.5 · 10 ^-5 g Pd / g Yak.

The only drawback of the known method using a highly active catalyst is the difference in the biological activity obtained by hydrogenation of high-purity UC from the biological activity of the “natural” UC obtained by pyrolysis of amber chips.

The technical task of the invention is to eliminate this drawback and obtain succinic acid, the biological activity of which corresponds to the biological activity of "natural" succinic acid.

The specified technical result is achieved by the fact that in the method for producing UC by hydrogenation of MA, MK or FC in an aqueous medium in the presence of a palladium-iron catalyst, which is a complex of palladium and water-soluble iron compounds deposited by adsorption on a carbon carrier, the process is carried out in the presence of palladium-iron the catalyst obtained when using the complex compounds of palladium complex salts of palladium and YAK, MK or FC and their adsorption on a carbon carrier at the time of formation Ania. The iron content in the catalyst in terms of metal is from 0.08 to 0.30 wt.%, Palladium - from 0.075 to 0.200 wt.% With a mass ratio of iron: palladium from 1.00: 0.25 to 1.00: 2 ,fifty.

The preferred iron content in the catalyst is from 0.15 to 0.25 wt.%, And palladium is from 0.09 to 0.11 wt.%. The preferred mass ratio of iron: palladium is from 1.00: 0.36 to 1.00: 0.73.

Any carbon carriers (active carbons OU-B, OU-A, CAD-ground and Sibunit, etc.) are used as a substrate.

The order of application of the active components can be any.

UC obtained by hydrogenation of MA, MK or FC according to the proposed method, is comparable in biological activity with "natural".

Moreover, the use of the proposed catalysts does not lead to a decrease in the productivity of the process compared to the closest analogue, the removal of the target product, referred to the unit mass of the precious metal used, is 445-1104 g UC / g Pd · min (i.e., not less, and sometimes more than the closest analogue).

The process of obtaining a biologically active UC does not become more expensive, the consumption of Pd per 1 g of UC does not increase compared to the method according to the closest analogue and amounts to 2 · 10 ^-5 -0.21 · 10 ^-5 g.

The catalyst preparation technology is not complicated either.

The use of catalysts having a lower metal content leads to a decrease in the activity of the catalyst and the productivity of the process in comparison with the closest analogue, a higher one also leads to an increase in the consumption of palladium per unit of produced YA its rise in price, but does not reduce the biological activity of UC.

The synthesis of the active phase of the catalysts can be described by the following series of successive transformations:

where L is Mal ^2- or Suc ^2- (Mal ^2- is the anion of MK or FC, Suc ^2- is the anion of UC).

The synthesis of palladium and iron complex compounds is carried out in an aqueous medium in the presence of a suspended carrier, and the complexes are adsorbed on the surface of the carrier.

The catalyst preparation technique involves suspending the carrier in an aqueous alkaline medium, applying palladium in the form of chelate complexes with maleic, fumaric or succinic acid (or maleates, fumarates, succinates) from an aqueous solution at the time of their formation and applying a modifying compound of iron.

As a substrate, it is preferable to use finely dispersed (≤ 400 μm) active carbons of various grades (OU-A, OU-B, CAD-ground, etc.), carbon carriers "Sibunit", ACB-0, etc., as water-soluble compounds iron - chlorides, sulfates, acetates of iron (II, III) and other compounds, including complexes.

The loading order of the components during the synthesis of the catalysts may vary, as reflected in the examples of catalyst synthesis (A) below.

A. Preparation of catalysts

In the examples below, the catalyst is prepared in laboratory (I) or in experimental (II) plants.

Example 1A Preparation of a catalyst sample with a calculated content of palladium 0.1 wt.% And iron 0.2 wt.% (In a dry catalyst) in the installation (I).

Pre-prepared stock solutions:

(a) 0.25 N aqueous KOH solution;

(b) ~ 0.0001 N aqueous solution of FeSO ₄ · 7H ₂ O;

(c) 0.05 N aqueous succinic acid solution;

(g) a solution of 0.0511 g of palladium chloride (palladium content 59 wt.%) in 1.5 cm ^{3 of} hot (65-70 ° C) water, acidified with 0.0038 cm ^{3 of} concentrated hydrochloric acid in the presence of 0.0336 g of chloride sodium, then partially hydrolyzed by adding 1.1 cm ^{3 of a} 0.25 N KOH solution.

300 cm ^{3 of} distilled water are charged into a round-bottom flask with a capacity of 1.0 dm ³ , then the mixer is turned on and 30 g (calculated on dry) of KAD-ground coal are loaded, the suspension is stirred for 2 minutes, then heated to ~ 50 ° C.

~ 60 cm ^{3 of} solution (a) is sequentially dosed to a coal suspension (initial pH 5-6) to pH ~ 9, solution (g), 14 cm ^{3 of} solution (b) and then 30 cm ^{3 of} solution (c).

Check the pH of the suspension and adjust the solution (a) to a value of 9-9.5, spend half an hour holding with constant stirring and a temperature of 50 ± 2 ° C, after which the suspension is cooled to 30-40 ° C and filtered. The precipitate of the catalyst on the filter is washed with distilled water to the absence of Cl ^- and a neutral pH, dried under vacuum to a residual moisture content of 30-40 wt.%.

According to atomic absorption spectrophotometric analysis (AAS), the mass fraction of palladium in the catalyst is 0.09%, the mass fraction of iron is 0.25% (calculated on the dry product).

Example 2A Preparation of a catalyst with a calculated content of palladium 0.1% and iron 0.1% (calculated on the weight of the dry carrier — OU-B coal) at the facility (II), which includes four containers with mixers for preparing the initial solutions, a synthesis reactor and a bag filter .

A solution of (1 N) sodium hydroxide is prepared in a container V = 5 dm ³ , loading 3.25 dm ^{3 of} distilled water and 135.5 g of sodium hydroxide (99.0% of the basic substance).

Iron chloride (FeCl ₃ · 6H ₂ O) in the amount of 18.4 g is dissolved with stirring in 0.9 dm ^{3 of} distilled water in a container V = 2 dm ³ .

In a container (V = 0.5 dm ³ ) with controlled heating, equipped with a stirrer and reflux condenser, a solution of the palladium complex salt (palladium chloride complex) is prepared, sequentially, with constant stirring, loading: 0.2 dm ^{3 of} distilled water; 0.5 cm ^{3 of} concentrated hydrochloric acid; 2.2 g of sodium chloride and (in portions) 6.78 g of palladium chloride (Pd content - 59 wt.%). The reaction mass is heated to 60-70 ° C and stirred until a solution of the palladium chloride complex is obtained, which is then hydrolyzed after cooling to 30-40 ° C, slowly dosing ~ 55 ml of a 1 N sodium hydroxide solution into the solution, followed by a two-hour exposure.

40 dm ^{3 of} water, 37.0 g of maleic anhydride or 43.8 g of maleic acid are loaded into the synthesis reactor with the stirrer turned on and then 4 kg of OU-B coal (calculated on dry basis), steam is fed into the reactor jacket and the reaction mass is heated to 50 ± 2 ° C. A solution of sodium hydroxide is dosed into a heated suspension to pH 9, then (slowly) a solution of the palladium complex and ~ 0.9 dm ^{3 of a} solution of iron chloride, maintaining the pH of the suspension at 9-9.5. At the end of the dosage of all components, hold for 0.5 hour and cool the suspension to 30-40 ° C, after which it is pushed with nitrogen (0.2-0.3 MPa) through a bag filter, where the catalyst is separated from the filtrate sent to the collector .

The catalyst on the filter is washed portionwise with 120 dm ^{3 of} water, and the washing water is also sent to the collector.

The washed catalyst is dried on a filter with nitrogen to a residual moisture content of ~ 55% and the catalyst is discharged as a wet paste in an amount of ~ 3.8 kg (in terms of dry).

According to AAS, the catalyst based on dry weight contains 0.11% palladium and 0.15% iron.

Example 3A A catalyst with a calculated palladium and iron content of 0.2 wt.% (In a dry catalyst) is prepared in a laboratory setup (I).

Initial solutions are pre-prepared (per 10 g of dry coal OU-B):

(a) 0.5 n solution of NH ₄ OH - 10 cm ³ ;

(b) 0.084 g Fe (C ₂ H ₃ O ₂ ) ₃ · 4H ₂ O is dissolved in 5 cm ^{3 of} distilled water;

(c) 0.0338 g of palladium chloride (59.5% Pd) is dissolved at a temperature of 65-70 ° C with constant stirring in the presence of 0.0112 g of sodium chloride in 1.0 cm ^{3 of} water, acidified with 0.0025 cm ³ concentrated of hydrochloric acid. The solution was cooled to 30-40 ° C and the resulting palladium chloride complex was partially hydrolyzed, slowly adding dropwise 0.28 cm ^{3 of} an alkali solution, after which the complex solution was kept for 2 hours at room temperature;

(c) 0.11 g MK is dissolved in 10 cm ³ H ₂ O.

In a round bottom flask with a capacity of 0.5 DM ³ load 100 cm ³ distilled water and (with the stirrer turned on) 10 g of activated carbon OU-B (in terms of dry). The suspension is heated to 60 ± 2 ° C with stirring. Dosing a 0.5 N solution of NH ₄ OH, the pH of the suspension is adjusted to ~ 9, after which the solution of the palladium chloride complex (c) and solution (c) are simultaneously dosed, the suspension is kept at a temperature of 50-60 ° C and stirring for 0.5 hours. After exposure to the suspension, the solution (b) is dosed, maintaining the pH of the suspension at the level of 9-9.5 by adding a solution of ammonium hydroxide. After the dosage of the components is completed, aging is carried out for one hour at a temperature of 55-60 ° C and constant stirring, then the suspension is cooled to 30-40 ° C and the resulting catalyst is separated from the liquid phase by vacuum filtration. The filter cake is washed with distilled water to a neutral environment and the absence of Cl ions in the wash water, dried under vacuum to a residual moisture content of 20-30 wt.%, Unloaded and analyzed.

The obtained catalyst according to AAS contains 0.18% palladium and 0.25% iron (calculated on the weight of the dry product).

Example 4A A catalyst with a mass fraction of palladium 0.2% and iron 0.1% (calculated on the dry product) is prepared on the installation (I).

100 cm ^{3 of} distilled water are charged into the flask, then with the stirrer switched on, 10 g (calculated on dry) of active carbon OU-A. The suspension is heated to 45-50 ° C and the pH is adjusted to ~ 9 by adding a 0.25 N NaOH solution (~ 12 cm ³ ).

To the heated suspension, with stirring, a previously prepared (see Example 3A) solution of the palladium chloride complex is slowly dosed, followed by a solution of 0.026 g of a mixed sodium-calcium salt of succinic acid in 1.0 cm ^{3 of} water. The suspension is kept under stirring for about an hour, then a solution of 0.092 g of iron chloride in 4.6 cm ^{3 of} distilled water is dosed at a pH of the suspension of 9-9.5. After a half hour exposure, the suspension is cooled, filtered and the filter cake washed (see Example 3A).

The finished catalyst contains 0.22% palladium and 0.2% iron (calculated on dry weight).

Example 5A A catalyst with a palladium and iron content of 0.1 wt.% (Calculated on dry basis) is prepared on the installation (I) analogously to example 3A with the following changes: in this example, the carbon carrier "Sibunit" is used and instead of a solution of maleic acid, a solution of sodium maleate ( Na ₂ C ₄ H ₂ O ₄ ) in a molar ratio of Pd ²⁺ : Na ₂ C ₄ H ₂ O ₄ 1: 1.

The finished catalyst according to AAS contains 0.08 wt.% Palladium and 0.1 wt.% Iron (calculated on the dry product).

Example 6A Installation (I), the synthesis of a catalyst with a calculated content of palladium 0.1 wt.% And iron 0.2 wt.% Is carried out according to example 2A, however, fumaric acid in a molar ratio of is introduced into a suspension of coal (CAD-ground) in an alkaline aqueous medium palladium 3: 1.

According to AAS, the mass fraction of palladium in the finished catalyst is 0.075%, iron - 0.30% (calculated on dry).

Example 7A According to example 4A, a catalyst with a calculated palladium and iron content of 0.2 wt% is prepared in installation (I).

The difference is that disodium salt of succinic acid is used to introduce the succinate ligand into the Pd complex.

The catalyst, calculated on the weight of the dry product, contains 0.18% palladium and 0.22% iron.

Example 8A According to Example 1A, a catalyst is prepared with a calculated palladium and iron content of 0.1 wt.%, Using the cellolignin processing product, ACB-O, as the carrier, and maleic anhydride in molar ratio to palladium 10: 1 instead of succinic acid.

The resulting catalyst according to the analysis contains 0.12 wt.% Palladium and 0.15 wt.% Iron (calculated on dry).

Example 9A The synthesis of a catalyst with a calculated content of palladium 0.2 wt.% And iron 0.1 wt.% (In a dry catalyst) is carried out on the installation (I).

In this example, the initial components for the synthesis of the active phase of the catalyst (palladium succinate complex) - the palladium chloride complex and the excess of the calculated amount of ammonium succinate are mixed beforehand, then dosed into a suspension of coal. In the process of their mixing, the reaction of formation of the active phase of the catalyst (palladium succinate complex) only begins and ends already in the presence of a carrier. However, as follows from table 1, the resulting catalyst showed a reduced (compared with other samples) activity in hydrogenation (see table 1, the number of experience of hydrogenation 4B). That is, although the biological activity of UC obtained on this catalyst is comparable with other UC samples, this dosage option is not optimal.

Initial solutions are preliminarily prepared (per 10 g of dry coal OU-A):

(a) 0.18 g of sodium hydroxide is dissolved in 4.3 cm ^{3 of} distilled water;

(b) 0.092 g of iron chloride (FeCl ₃ · 6H ₂ O) is dissolved in 4.6 cm ^{3 of} distilled water;

(c) 0.0338 g of palladium chloride (59.5% Pd) is dissolved at a temperature of 65-75 ° C with constant stirring in the presence of 0.0112 g of sodium chloride in 1.0 cm ^{3 of} water, acidified with 0.0025 cm ³ concentrated of hydrochloric acid. The solution was cooled to 30-40 ° C and the resulting palladium chloride complex was partially hydrolyzed, slowly adding dropwise 0.28 cm ^{3 of} an alkali solution, after which the complex solution was kept for 2 hours at room temperature. At the end of the exposure, an aqueous solution of 0.0347 g of ammonium succinate in 0.5 cm ^{3 of} water is metered into the resulting solution with stirring. After the end of the dosage - exposure for 5-10 minutes.

In a round-bottom flask with a capacity of 0.5 dm ^3, 10 g of OU-A charcoal are suspended in 100 cm ^{3 of} distilled water for 2-5 minutes, then the suspension is heated to 40 ± 2 ° C. The solution is adjusted to a pH of ~ 9 with solution (a) ( ~ 3 cm ³ ), then the solution (c) is dosed and the suspension is maintained at the same temperature and stirring for 0.5 hours. After exposure to the suspension, the solution (b) is dosed, maintaining the pH at the level of 9.0-9.5 by adding solution (a). After the dosage of the solution (b) is completed, exposure is carried out with constant stirring for 0.5 hours at a temperature of ~ 50 ° C, then the suspension is cooled to 30-40 ° C and the resulting catalyst is separated from the liquid phase by vacuum filtration. The filter cake was washed with distilled water until neutral pH and absence of ions Cl ^-. In the wash water, dried in vacuo to a residual humidity of 20-30 wt%, discharged and analyzed.

According to atomic absorption spectrophotometric analysis (AAS), the finished catalyst contains 0.20% palladium and 0.08% iron (calculated on the weight of the dry catalyst).

The proposed catalysts are used in the process of producing succinic acid by hydrogenation of maleic anhydride, maleic or fumaric acid in an aqueous medium in wide ranges of temperature and pressure of hydrogen; these parameters affect the hydrogenation rate, and, accordingly, determine the activity of the catalyst, as illustrated in the following examples of the synthesis of succinic acid (B).

B. Synthesis of succinic acid

The synthesis of succinic acid is carried out at three different scale plants:

I - laboratory kinetic hydrogenation unit at constant temperature and pressure with a reactor capacity of 0.1 dm ³ ,

II - model hydrogenation unit with an autoclave with a capacity of 1.0 dm ³ ,

III - a pilot plant of periodic action, including a suspension and a hydrogenation reactor with a capacity of 100 dm ³ each, a heated filter for separating the catalyst, a crystallizer and a suction filter for separating the product.

When succinic acid is isolated from the solution (after separation of the catalyst), cooling, freezing or evaporation of the catalysis is used.

Table 1 shows examples of the production of succinic acid by hydrogenation of maleic anhydride (MA), maleic acid (MK), fumaric acid (FC) according to the proposed method. The table contains the hydrogenation conditions [temperature (T, ° C), excess hydrogen pressure (P (g), MPa)], the used catalysts for loading, the number of cycles in which the catalyst retains high activity. The hydrogenation results include indicators such as the activity (A) of the catalyst (cm ³ H ₂ / min · g Pd), its productivity (g succinic acid / g Pd · min) and the rate of palladium consumption (g Pd / g succinic acid) calculated after its single or multiple use. In addition, the table shows an example of obtaining succinic acid using a catalyst proposed by the closest analogue.

UC samples were compared by chemical composition (including the presence of heavy metals), microbiological contamination, and physical properties. All of them fully corresponded to GOST 6341 "Succinic acid" (hch) and the requirements for food succinic acid (code E-363, SanPiN 2.3.2.1078-01).

In addition, the spectral characteristics were evaluated according to the method proposed by P.P. Garyaev and G.G. Tertyshny (P.P. Garyaev. The wave genetic code, M., EPU RAS, 1997). All UC samples obtained by the proposed method (table 1) have the same autocorrelation functions described below, therefore, the synthesized samples are further reduced to the description of sample 6 (table 2). The essence of bimodal radio wave spectroscopy is to process crystals or unsaturated aqueous solutions with a red bimodal laser for 4 seconds while simultaneously taking off the radio wave characteristics of the resulting radiation and then processing them.

Apparently, the pseudopolymerized UC is responsible for the appearance of a multiplicity of autocorrelation functions superimposed on the samples obtained by the proposed method and on the “natural” sample.

Figure 4 shows the autocorrelation functions of a sample obtained by pyrolysis of amber chips. As can be seen from the figure, at the same time there are four autocorrelation functions superimposed on each other, the fourth of which corresponds to the pseudopolymer. Figure 6 presents the functions of the sample obtained by the proposed method. For a reason unknown to us, it has amplitude displacements with respect to the sample obtained by pyrolysis, but also has an overlap of all four functions that coincide with figure 4 in terms of the half-period parameter. In contrast to the pyrolysis sample, sample 6 has a whole package of weakly expressed additional functions, which, apparently, is associated with a different degree of polymerization of the pseudopolymer UC (Fig.6). In contrast to these samples, the sample obtained by a known method (the closest analogue), and the remaining samples have a mono-autocorrelation function (figures 1, 2, 3, 5).

A comparison is made (table 2) of the biological activity of UC samples synthesized by the proposed method and UC samples of industrial production obtained by other methods.

The biological activity of UC samples was studied in two groups:

- antihypoxic and adaptogenic properties in a group of 16 volunteer cadets;

- cardiotonic and antiarrhythmic properties in a group of 11 elderly people who have suffered at least one heart attack.

An informed agreement was signed with each volunteer from both groups to conduct a study in the form of the Ethics Committee of the Ministry of Health of the Russian Federation. The biological activity of the samples obtained by the proposed method (table 1) does not differ significantly, therefore, they are all reduced to the average sample 6 (table 2).

The antihypoxic and adaptogenic properties of UC samples were studied under conditions of hypoxic hypoxia and the rate of exit from it. A group of volunteers - cadets of a military school 10 minutes before the start of the test was given 100 mg of UC or 100 mg of chalk in powder. The powder was washed down with water. Samples were encrypted with numbers, including chalk - placebo.

Then the cadets were subjected to a simulated rise in a pressure chamber until the loss of consciousness. This moment was recorded as the height reached. Then the cadets were "lowered to the ground" and given them the same powder as before the pressure chamber. After 10 minutes, they passed a test for the accuracy of getting a thin probe into the holes of the card. The hit was recorded by closing the contacts located in the holes of the card. Got the following results:

rise height with chalk reception 5900 m

lifting height with samples 1, 2, 3 (see No. p / p table 1) 5950 m

lifting height with sample 5 - 6000 m

lifting height with sample 4 - 6150 m

lifting height with sample 6 - 6270 m.

The speed of the map is as follows:

with placebo - 16 seconds

with samples 1 and 2 - 14 seconds

with samples 3 and 5 - 13 seconds

with a sample of 4 - 11 seconds

with a sample of 6 to 10 seconds.

The cardiotonic and antiarrhythmic properties of UC samples were studied in the period 1998-2001 on a group of elderly people of 7 men and 4 women, each of whom suffered at least one heart attack and, therefore, has an increased sensitivity. Each of the volunteers over the years kept a diary where they recorded subjective sensations in the point system. In this case, volunteers periodically received not only UC obtained by the proposed method, but also other UC samples (without placebo). The dose of a single dose was 100 mg of UC. The assessment was carried out according to the following point system:

Diuretic activity:

absence - 0

weak activity - 1

strong activity - 2.

Cardiotonic activity:

absence - 0

weak activity - 1

average activity - 2

strong activity - 3.

Antiarrhythmic activity:

absence - 0

weak activity - 1

average activity - 2

strong activity - 3.

The time to relieve symptoms of an attack:

more than 20 min - 0

15-20 min - 1

10-15 min - 2

less than 10 min - 3.

The results are presented in table 3.

As can be seen from table 3 and the description of the experiment on hypoxic hypoxia, the biological activity of samples 4 and 6 is maximum, while the activity of samples 1, 2 and 3 is only diuretic. Moreover, the UC obtained by the proposed method (sample 6) significantly surpasses the “natural” UC obtained by pyrolysis from amber chips (sample 4) in its properties and has increased cardiotonic, antiarrhythmic, adaptogenic and antihypoxic properties.

Claims (2)

1. The method of producing succinic acid by hydrogenation of maleic anhydride, maleic or fumaric acid in an aqueous medium in the presence of a palladium-iron catalyst, which is a complex of palladium and water-soluble iron compounds deposited by adsorption on a carbon carrier, characterized in that the process is carried out in the presence of palladium- the iron catalyst obtained when using the complex compounds of palladium and amber, maleic or fumaric as palladium complex compounds isloty and their adsorption on a carbon support at the time of formation. 2. The method according to claim 1, characterized in that the iron content in the catalyst in terms of metal is 0.08-0.30 wt.%, Palladium 0.075-0,200 wt.% And the mass ratio of iron: palladium 1.00: 0 25-1.00: 2.50.

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