SK114197A3 - Process for producing azelaic acid and/or malonic acid and/or their methylesters - Google Patents

Abstract

Disclosed is a process for ozonising glycerides and/or alkylesters, and/or free, mostly unsaturated C16 - C22 carboxylic acids at a temperature ranging from 0 to 130 DEG C, followed by ozonides decomposition and oxidation of thus formed aldehydic groups into carboxylic groups, whilst said ozonisation being conjugated with the ozonides decomposition and oxidation at above 50 DEG C is carried out in a single technological phase. The ozonisation, as well additional oxidation of ozonides decomposition products, is carried out by means of ozone-containing gas and/or oxygen- and ozone-contaninig, whilst an azelaic, malonic and pelargonic acid as well as other lower carboxylic acids are isolated from the raw reaction product by distillation, extraction, ozonised glycerides and methyl esters extraction, usually after methyl esters hydrolysis or pre-esterification, distillation at decreased pressure, extraction by water as well as by aliphatic or cycloaliphatic ketones (acetone, methylethylketone, diethylketone, methylisobutylketone, cyclohexanone, methylcyclohexanone, cyclopentanone) and aliphatic or cycloaliphatic ethers (diethylether, methyl-terc.butylether, methyl-terc.amylether, tetrahydrofurane).

Description

Process for producing azelaic acid and / or malonic acid and / or methyl esters thereof

Technical field

The invention relates to a process for the preparation of azelaic acid and / or malonic acid and / or methyl esters thereof by ozonization, followed by operations from readily available starting olefinically unsaturated compounds, in particular vegetable oils, methyl esters of predominantly unsaturated carboxylic acids, but also mixtures, predominantly unsaturated carboxylic acids.

BACKGROUND OF THE INVENTION

Most of the known processes for the preparation of azelaic acid are based on oleic acid as the starting material, which can be oxidized with a chromium mixture, respectively. potassium permanganate or sodium chlorate. Due to the complexity of the reaction mixtures, the cost and especially the ecological reasons, these processes for the production of azelaic acid are currently unusable. The most interesting processes are those based on the oxidation of oleic acid with oxygen or a mixture of oxygen and ozone [Goebel Ch. G. et al., U.S. Pat. No. 2,813,113 (1957)]. Oxidation, resp. the ozonation is carried out at a temperature of about 45 ° C and furthermore the ozonated oxidizing acid decomposes at a temperature of about 85 ° C to azelaic acid and pelargonic acid. In other methods, ozonation of an unsaturated acid or salt thereof in an aqueous emulsion is optionally carried out, optionally in the presence of trihydrogenphosphoric acid, which aids in the decomposition of ozonides [U.S. Pat. GB 810571 (1959) and 884438 (1961); C.A. 57, 4549i; Juriev J. H. et al .: USSR 330,154 (1972); Melamud N.L. et al .: USSR 238,535 (1969).

In similar processes, the ozonation is carried out with oxygen-containing ozone continuously in an absorption column at a temperature of 20 to 40 ° C, to which oxygen containing 2% ozone is introduced at the bottom and a solution of oleic acid in pelargonic acid flows from above. The decomposition of the ozonides from the column is carried out at a temperature of 100 ° C in the presence of manganese salts, the purity of oleic acid being at least

% [Swedish Pat. 133,160 (1951); J. Oil Chem. Soc. 61, No. 2, 229 (1984)]. The crude product, consisting of a mixture of azelaic acid and pelargonic acid, also stearic acid and palmitic acid, with other products is separated by distilling off the pelargonic acid, extracting the azelaic acid with hot water and finally, separating the azelaic acid from the aqueous solution by distillation or crystallization. However, only azelaic acid of technical quality is obtained by these processes. In addition, when sodium oleate is ozonized, there are problems with displacing azelaic acid and pelargonic acid from their sodium salts and utilizing the sodium salts thus removed.

Seemingly simpler is the catalytic oxidation of unsaturated long chain carboxylic acids with liquid oxygen in the liquid phase, in the presence of organic solvents such as propanol and the catalytic effect of cobalt salts at 80 to 90 ° C [US 2,820,046], but azelaic acid is produced in relatively low yield next to a varied mixture of difficult-to-isolate by-products.

Higher selectivity to azelaic acid is achieved by oxidation of oleic acid with hydrogen peroxide, in the presence of formic acid at 30-60 ° C, followed by ioxidation with molecular oxygen in acetic acid and catalytic action of cobalt or manganese salts, sodium bromide and zirconium chloride [Sapunov VV: USSR 1 766 905 (1992)], but this method is technologically and resource-intensive. In addition, selectivity to azelaic acid is still low and azelaic acid is difficult to isolate from the reaction mixture. Similar results are also obtained by oxidation with hydrogen peroxide in the presence of the acids: tungstic, phosphomolybdenic and quaternary ammonium salts [Katsuna Akoi: JP 0 504 938 (9304938); 119, 10788c (1993)].

The oxidation of oleic acid by air and dooxidation by nitric acid [Morgan Ch. S. et al: US 2,847,431 (1958)], but the selectivity to azelaic acid is not very high, while the by-products present present make it too difficult to isolate high purity azelaic acid. These drawbacks are also characteristic of oxidation processes with nitric acid alone [US 2,773,095, 2,560,156, 2,662,908, 2,773,094].

The processes of oxidation of vicinal diols, in particular 9,10-dihydroxystearic acid to azelaic acid, catalytic (cobaltic acetate) oxidation by oxygen or air, are interesting, but technologically, operationally and investment intensive [pat.

prihl. Germany 2,316,203 (1974) and 2,144,015 (1972); JP 7,354,017 (1973); C.A. 80, 3095xJ. However, the selectivity to azelaic acid is low although it is easier to isolate from the crude product. For the preparation of malonic acid, the older process based on chloroacetic acid, resp. its ethyl ester, followed by cyanization and hydrolysis or saponification, although they are known [Sinoda Kijonosi et al .: Pat. prihl. JP 6197245 (1986); 62-36342 (1987) and 62-36343 (1987)] interesting processes for the carbonylation of haloacetic acid on radio or iridium homogeneous catalysts, at 100 to 300 ° C, diethyl malonate and hydrogen chloride are formed. The method according to the invention solves the disadvantages of the prior art.

The essence of the invention

The present invention provides a process for the preparation of azelaic acid and / or malonic acid and / or their methyl esters by ozonation and oxidation with oxygen, ozone and / or oxygen-containing gas unsaturated organic compounds at a temperature of 0 to 130 ° C. methyl esters and / or free at least two predominantly unsaturated carboxylic acids C 1 to C 22. selected from oleic acid, elaidic acid, oleosteic acid, palmitoolic acid, linoleic acid, linolenic acid and peanutic acid, with at least one methyl ester and / or glyceride and / or a free saturated carboxylic acid and at least one saturated organic solvent and / or catalyst, ozone-containing gas or an ozone-gas-containing gas mixture until 35-100% of the double bonds of the ozonized feedstock have reacted, and this is subsequently thermally or thermally-catalytically cleaved and oxidized under the influence of oxygen and / or 35-100% of the double bonds at 50-50 130 ° C and treatment with oxygen-containing and / or ozone-containing gas is carried out simultaneously with ozonization followed by decomposition of the conjugated oxidation of the formed aldehyde groups to carboxylic acids and the resulting reaction product, usually after treatment, leads to separation of the and hydrolysis and / or transesterification with formic acid, associated with the separation of methanol and / or glycerol and / or methyl formate. Thereafter, the mixture of monocarboxylic and dicarboxylic acids or their esters is further separated, such as by distillation under normal or reduced pressure, by extraction with water and / or with at least one polar organic solvent, by one to four stages extraction, thereby isolating at least part of the carboxylic acids and water. by at least one aliphatic and / or cycloaliphatic oxygen compound selected from ketones, ethers, azelaic acid is isolated in one to three extraction steps, generally after separation of a substantial portion of pelargonic acid and other monocarboxylic acids and / or reaction product after ozonation, ozonide decomposition and dooxidation to 85-100% does not etherify with methanol and the mixture of monocarboxylic esters and dicarboxylic acid diesters obtained is separated by a known method.

An advantage of the process according to the invention is the high selectivity of ozonization, ozonide decomposition and dooxidation of the formed intermediates to partial esters of dicarboxylic acids and after their treatment up to malonic acid and azelaic acid, as well as C3 to C8 monocarboxylic acids or their esters. The advantage is also the production of at least two valuable products or intermediates from one starting material and the possibility in one technological stage or even in one reactor to carry out ozonization conjugated with ozonide decomposition and dooxidation to carboxylic acids or dicarboxylic acid precursors.

The advantage is also the raw material availability of vegetable oils, especially rapeseed oil, but also methyl esters of rapeseed acids, as well as mixtures of predominantly unsaturated acids, formed as a by-product in the production of methyl esters of rapeseed acids, so-called. biodiesel. Also advantageous is the simultaneous production of technically important monocarboxylic acids, such as pelargonic, propionic and caproic acids, as well as other by-products. Last but not least, the advantages of the process include the practical waste-free technology and the high purity of azelaic acid and malonic acid achieved.

The mixture of the glycerides or methyl esters of the predominantly unsaturated carboxylic acids is formed from at least one vegetable oil selected from rapeseed oil, and flax, hemp, cotton, soybean, tall and tung oil. Other valuable oils such as walnut, poppy seed and the like are also suitable, but technically they are only too difficult to access. Of fish oils, it is mainly whale and herring oil. Similarly, mixtures of predominantly unsaturated acids as well as their methyl esters are obtained from such starting materials.

As a component of at least one acid or one saturated acid ester, acids and esters or at least partial glycerides of saturated acids such as: palmitic, stearic, lauric, arachic and the like are formed.

The catalyst is, on the one hand, an acidic catalyst for the decomposition of ozonides, which can form a soluble mineral or carboxylic acid in the reaction medium, as well as a solid insoluble acid such as sulfonic resin, alumosilicates, in particular acidified bentonite, montmorillonite or zeolite. However, this function can also be performed by a solvent, in particular carboxylic acids such as formic, acetic and the like. Their amount is determined mainly by application and especially regeneration possibilities. However, in the case of transition metal salts of carboxylic acids, in particular cobalt, manganese and copper, which catalyze oxidation, it is suitable to apply 0.001 to 0.5 wt. % metal calculated on the oxidized substrate.

Saturated organic solvents are solvents which dissolve only the ozonated acids, esters and oils, but are not practically ozonized by themselves. These include lower carboxylic acids, in particular formic acid and acetic acid or its anhydride and liquid formates or alkyl acetates, then lower aliphatic alkanols, especially methanol, under normal conditions liquid aromatic or naphthenic hydrocarbons. At higher ozonization temperatures, in particular 50 to 100 ° C, the decomposition of the ozonides and the dooxidation of the aldehyde groups to the carboxyl groups take place simultaneously. It should be ensured that the decomposition of the ozonides and the conjugated oxidation proceed as completely as possible, at least to 85%. Complete decomposition of ozonides and dooxidation not only significantly increase the yield of the final products in the ozonation-oxidation part of the process, but also in the isolation and refining of mainly azelaic acid and malonic acid.

The treatment according to the invention is carried out by auxiliary operations such as catalyst separation, dooxidation of the intermediate, neutralization, stripping and the like.

The crude product after ozonization and decomposition with dooxidation is freed from at least partially mainly volatile products, such as by distillation, in particular under reduced pressure, by extraction with water, thereby extracting at least part of the malonic acid etc. or after hydrolysis, preferably under catalytic action. and thus allowing the separation of pelargonic acid or lower carboxylic acids, while not too difficult to isolate and refine the azelaic acid and optionally the malonic acid. A solvent such as formic acid, acetic acid, heteropoly organic substances, such as polyglycol, dimethyl glycol ether and the like, dissolving both water and a hydrolyzed substrate or an easily removable phase transfer catalyst also serve to improve contact of water with the hydrolyzed intermediate. Instead of hydrolysis of the methyl esters of carboxylic acids, transesterification with formic acid can be utilized to give the free carboxylic acids and methyl formate.

In carrying out the process according to the invention, it is ensured that, due to the thermal lability of the malonic acid and its esters, the temperature in any operation does not exceed a temperature of 140 ° C. Therefore, rectification and distillation in carrying out the process according to the invention are generally carried out under reduced pressure. It is therefore generally advisable, after separation of the volatile components, even in the case of the ozonation of glycerides and methyl esters of carboxylic acids, to separate the malonic acid first, in particular by extraction with water or other selective solvents.

Other non-limiting data as well as other advantages are apparent from the examples.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Weigh 250 g of methyl esters prepared with potassium hydroxide, catalyzed by transesterification of rapeseed oil with methanol, whose thunder number was 65.3 g Br / 100 g and saponification number 172.05 mg KOH / g, were weighed into a 1.5 m ³ glass-jacketed ozonation reactor. . GLC analysis shows the following methyl ester composition (w / w): palmitic acid 4; stear 1,2; oil 68.2; linoleum 11.5; linolene 17.5; arachic 2.9 and behenic 2.5. Further, 750 g of acetic acid are added. After the reactor contents have been brought to a temperature of 11 ± 1 ° C and already purged with oxygen at a rate of 1.5 dm ³ / min, the pure oxygen is replaced by a purged through the ozonator (alternating current at 15.5 kV), with an ozone content of 40 mg / ^dm3, i.e., 2.91 wt. %. The power consumption of the ozonator is 0.23 kW. Already after 5 hours of ozonization, by determination of the bromine number, the complete conversion of the unsaturated methyl esters has been demonstrated, with the ozone-containing oxygen supply being interrupted after 7 hours. The ozonator is then switched off and the dissolved ozone is expelled from the reaction medium with pure oxygen.

The total crude product, after ozonation, with acetic acid as a diluent, a solvent and an acidic ozonide cleavage catalyst, weighs 882 g.

441 g of this quantity are taken and heated at 85 ± 5 ° C under reflux with oxygen for 4 hours. Thereafter, acetic acid was removed by rectification under reduced pressure, and propionic and caproic acid were also removed under vacuum. Thereafter, the entire distillation residue is thoroughly extracted with water to extract malonic acid and the remainder of caproic acid. Furthermore, a substantial part of pelargonic acid is distilled off under an even deeper vacuum. Next, a distillation residue with a quadruple excess of superheated steam is injected into a pressurized hydrolysis reactor at a temperature of 230 to 260 ° C containing the tableted acidified bentonite. The catalyst loading with methyl acid esters is 0.22 g / cm @ 2 cat./h. Methanol is distilled off from the obtained hydrolyzate and the bulk mixture of acids is subjected to extraction by concentration and concentration and crystallization using water, methyl ethyl ketone, methyl tert-butyl ether as extracting agents.

The products obtained are weighed and the acid yields are calculated from theoretically possible yields such that after ozonization, ozonide decomposition and dooxidation from oleic acid, azelaic acid and pelargonic acid are formed.

CH3 (CH 2) 7 CH = CH (CH 2) 7 COOH => HOOC (CH 2) 7 COOH + CH ₃ (CH 2) 7 COOH from linoleic acid (9,12-linoleic acid) in turn azelaic acid, malonic acid and caproic acid

CH ₃ (CH 2) 4 -CH = CH-CH 2 CH ₂ CH = CH (CH ₂ ) 7 COOH => HOOC (CH ₂ ) 7 COOH + + HOOCCH 2 COOH + CH ₃ (CH 2) 4 COOH, azelaic acid, malonic acid and propionic acid from linolenic acid CH 3 CH 2 CH = CHCH ₂ CH = CHCH ₂ CH = CH (CH ₂ ) 7 COOH => HOOC (CH 2) 7 COOH + + 2 HOOCCH 2 COOH + CH ₃ CH ₂ COOH.

Pelargonic acid and brazylic acid are again formed from erucic acid.

The yield of malonic acid after extracting three times and again concentrating the aqueous solution three times and extracting also the mother liquors reaches 57.8% of theory, azelaic acid of 66.7% with a purity of 99.1% and pelargonic acid of 72.1% of the theory. The residue, along with other oxygenated organic compounds, remained in the mother liquors from which the carboxylic acid mixtures used, further used for the production of synthetic lubricants, were isolated.

A further 441 g was treated similarly, but only 0.15 wt. % cobalt capronate as oxidation catalyst and 1 wt. % of the bleaching active clay as ozonide cleavage catalyst, the temperature being lowered to 78 ± 5 ° C. Only water and methyl ethyl ketone are used to extract the azelaic acid.

The yield of malonic acid is 61.3% of theory, high purity azelaic acid is 74.2% and pelargonic acid is 74.4% of theory.

Example 2

The procedure is similar to that of Example 1, except that a mixture of unsaturated and saturated linseed acids is used instead of methyl esters of rapeseed oil which, due to the relatively high content of linoleic and linolenic acid methyl esters, also provide significantly higher amounts of malonic acid. The yield of malonic acid is 73.8% and that of azelaic acid is 74.1% of the theoretical yields.

However, using linseed oil, i.e. glycerides instead of methyl esters, under otherwise similar conditions, the yield of malonic acid is only 42.3%, azelaic

51.2% and geranium 58.9%. Even using herring oil, the yields are similarly low.

Example 3

From a technical mixture containing 80 wt. % of azelaic acid, the remainder being glargonic acid and admixture of other, mainly saturated carboxylic acids, yields a highly pure (i.e., at least 99 wt% purity) azelaic acid by two-stage crystallization extraction.

To 100 g of this technical mixture is added 200 g of methyl ethyl ketone, and after dissolution of all the technical mixture of azelaic acid with further admixtures at a temperature of 70-80 ° C, the solution is allowed to slowly cool while crystallization slowly proceeds. Next, the crystallizing mixture is cooled to 4-5 ° C. The crystals are then filtered off with suction, washed with still cold methylethylketone (3 * 20 cm @ 3) and, after drying, the crystals obtained are 74.5 g, which is azelaic acid having a purity of 97.8% by weight. %. In addition, 97.5 g of mother liquor ("lye") is obtained.

In addition, 50 g are taken from 74.5 g of crystals and dissolved at 60 to 65 ° C in 75 g of methyl ethyl ketone, whereby after similar crystallization, filtration and washing of the crystals three times with 20 g of methyl ethyl ketone each, mother liquor ', 47.0 g of azelaic acid having a purity of 99.1% by weight. % and melting temperature

107.5 ° C.

The yield of high purity azelaic acid achieved without the treatment of the mother liquors reaches 70%, and after treatment in three stages the concentration of the mother liquors yields a further 5.2% of pure azelaic acid.

Acetone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, diethyl ether, methyl tert-butyl ether and methyl tert-amyl ether were also used as extraction agents instead of methyl ethyl ketone (2-butan-2-one) alone. The results of the two-stage extraction conjugated to the crystallization of azelaic acid are shown in Table 1.

In the case of more volatile extracting agents, dissolution was carried out at a temperature close to the boiling point of the solvent. The mother liquors were treated separately.

Tab. 1

Solvent - extraction After 1st stage of extraction [%] After 2nd stage of extraction [%]

agent yield purity yield purity diethylether diethylether: 64.0 94.9 54.2 99.0 1 : Methyl ethyl ketone (1: 1) 66.3 95.5 56.1 99.2 methyl tert-butyl ether methyl tert-butyl ether: 44.1 94.9 49.3 98.9 cyclohexanone (1: 1) methyl isobutyl ketone: 67.2 94.9 57.2 98.8 : cyclohexanone methylethylketone: 66.9 95.3 58.8 98.2 : acetone (3: 1) methyl ethyl ketone: methyl- 69.2 94.4 59.2 99.1 tert-amyl ether (3: 1) 69.9 95.1 60.1 99.2

Example 4

Weigh 250 g of olein with an iodine value of 100.4 g of J2 / 100 g, a thunder number of 59.5 g of Br / 100 g, an acid number of 192.61 mg KOH / g and a saponification number of 96.90 into the ozonator as described in Example 1. mg KOH, in which the oleic acid content is 79.1 wt. % and linoleic acid 1.8 wt. %. Further, 750 g of acetic acid are added. The ozonation is carried out similarly to Example 1, except that the temperature of the ozonation reactor is maintained in the range of 68-73 ° C. After 250 min, double bonds are already reacted in the reaction medium, but the ozonation stops after 360 min. After expulsion of the remainder of the ozone, 500 g is separated from the crude reaction product, in an amount of 962.5 g, and subjected to conditions of thermal decomposition and oxygen dooxidation at 80 ± 5 ° C for 3 h. Then, acetic acid with the addition of caproic acid is distilled off under reduced pressure. The distillation residue is shaken vigorously at room temperature for 1 h with water, from which malonic acid is then isolated. Pelargonic acid is distilled off at an even deeper vacuum (0.54 kPa) and the azelaic acid is obtained from the distillation residue by extraction with water at 70 and 90 ° C, followed by cooling, crystallization with separation of crystals and reextraction with methylethylketone and diethyl ether. Yields of theoretically possible amounts are obtained (in% of theory): azelaic acid 84.1; pelargonic acid 86.3; malonic acid 42.1.

From a further 400 g of the ozonation product, distillation under reduced pressure of acetic, propionic and caproic acid, extraction with water of malonic acid, isolation of pelargonic acid and azelaic acid is carried out without subsequent thermal decomposition of the dooxidized ozonides. The yield of azelaic acid is 80.3% and of malonic 44.3% of theory. This suggests that, in the ozonization step, the decomposition of ozonides with subsequent dooxidation also takes place.

I

Example 5

The procedure is analogous to Example 4, but the mixture of unsaturated and saturated carboxylic acids contains (in wt.%): 62.3 oleic acid, 14.3 linoleic acid and 8.3 linolenic acid. The yields are (in% of theory): malonic acid 52.1, azelaic acid 82.1 and pelargonic acid 84.7.

Example 6

The feed to the ozonation reactor consists of 250 g of the rapeseed oil methyl esters specified in Example 1 and 750 g of toluene. The ozonation is carried out at a temperature of 74 ± 3 ° C with an oxygen-containing ozone flow similar to Example 1, the ozonization being terminated after 330 min.

In the second case, in addition to 250 g of methyl esters and 750 g of toluene, 25 g of powdered bleaching earth as an acid catalyst is added to the ozonation reactor.

While the first variant, without subsequent separate decomposition and dooxidation, the yield of azelaic acid reaches (in% of theoretical yield) 76.7, malonic acid 57.2, from the second variant also without a particular degree of decomposition and dooxidation, but additionally 10 wt. % of a heterogeneous acid catalyst, resulting in azelaic acid of 81.1% and malonic acid of 66.3%.

Example 7

The mixture of unsaturated and saturated carboxylic acid methyl esters specified in Example 1 is ozonized under otherwise similar ozonization conditions, only the temperature is 52-54 ° C and methanol is applied instead of acetic acid as solvent. The ozonation is removed after 330 min, the decomposition of the ozonides with dooxidation being carried out in the presence of bleaching clay and 0.3 wt. % phosphoric acid for 6 h. A mixture of methyl esters and dimethyl esters of propionic, caproic, pelargonic, malonic and azelaic acids is obtained, which is separated by rectification and distillation under reduced pressure. The yield of azelaic acid dimethyl ester (in% of the theoretical yield) was 62.4, malonic acid dimethyl ester 50.3, pelargonic acid methyl ester 63.1 and capronic acid 67.2.

Example 8

360 g of distillation residue of the organic layer, as a by-product of rapeseed oil methyl esters of bromine number 70.40 g Br / 100 g, iodine number 99.80g J / 100 g, acid number 92, are weighed into the ozonator specified in Example 1. , 7 mg KOH / g and saponification value 186.32 mg KOH / g. representation

II of free unsaturated and saturated carboxylic acids as well as in the form of methyl esters is (in%): acid. palmitic 5.3, acid. stearic acid 1,5, acid. arachic 0.6, acid. palmitooleate 0.3, acid. oleic acid 30.5, acid. linoleic 20.3, acid. linolenic 10.6, acid. galoleic 0.3 and acid. erukovej 0,3. To this was added 842 g of glacial acid. acetic acid and ozonization are carried out at a temperature of 66-84 ° C, with an ozonated oxygen flow of 1.6-1.9 dmS / min, an ozone content of 38 mg / dm 2 of oxygen, for 6 h. Already in 4.5 hours virtually all double bonds will be converted by thunder analysis. After 6 h reaction in the ozonator by chromatography the determined conversion is (%): acid. oil, respectively. its methyl ester 93.4, acid. linoleic 92.6 and acid. linolene 72.6. The crude product was rectified under reduced pressure (2.67 kPa), separating acetic acid with some of the entrained propionic acid. Next, the propionic acid is separated. The distillation residue is then extracted with water to extract malonic acid, the yield of which after three extractions reaches 71.2% of theory and the residue of caproic acid is distilled off. Thereafter, the distillation residue is subjected to hydrolysis in an autoclave at a six-fold excess of water in the presence of 2.9 wt. % bleaching earth at 230 to 248 ° C for 5 h. Subsequently, methanol is distilled off from the hydrolyzate and the organic residue is extracted with water, followed by methyl ethyl ketone and methyl tert-butyl ether to isolate azelaic acid and pelargonic acid. The yield of azelaic acid is reached

74.3% and pelargonic acid 71.3% of theory.

In another experiment, performed under similar conditions, the distillation residue was hydrolyzed non-catalytically with a seven-fold excess of water at 242 to 252 ° C for 5 h. The yield of azelaic acid reached 75.8% of theory and pelargonic acid 74.2% of theory.

Example 9

The procedure is similar to that in Example 8, except that the ozonation temperature is higher and the hydrolysis is omitted, and instead of the by-product (a mixture of acids and methyl esters of rapeseed oil) a mixture of carboxylic acids obtained from tall oil of this composition is used. %): acid. oleic acid = 45.2; linoleic = 44.8, acid. limolene = 7.4. The ozonation temperature for 6 h is 76-88 ° C. The conversion of unsaturated carboxylic acids reaches 94.8 to 97.4%. The yield (%) of malonic acid is 76.4, azelaic acid 79.6 and pelargonic acid 84.1.

Example 10

The procedure is analogous to the first variant of Example 6. Instead of catalytic hydrolysis of the distillation residue, the transesterification of pelargonic acid methyl ester and methyl azelaic acid ester is used with a triple excess of formic acid at a temperature above 90 ° C while separating the methyl formate. The yield of azelaic acid is 75.3% and that of pelargonic acid is 75.9% of theory.

Industrial applicability of the invention

The process according to the invention is applicable in the chemical and pharmaceutical industries for the selective production of valuable intermediates from technically and commercially readily available starting materials such as rapeseed and linseed oil, in particular mixtures of unsaturated and saturated carboxylic acid methyl esters prepared by catalyzed transesterification of rapeseed or linseed oil with methanol. . A mixture of such methyl esters of rapeseed acid is produced on medium scale as an ecological fuel for diesel engines, as a so-called diesel fuel. biodiesel.

Claims (10)

Process for the preparation of azelaic acid and / or malonic acid and / or their methyl esters by ozonation and oxidation with oxygen, ozone and / or oxygen-containing gas, unsaturated organic compounds, at a temperature of 0 to 130 ° C, characterized in that and / or methyl esters and / or free, predominantly unsaturated C18 to C22 carboxylic acids selected from oleic acid, elaidic acid, linoleic acid, linolenic acid, oleosteic acid, palmitoolic acid and peanutic acid, with at least one methyl ester and / or glyceride, and / or a free saturated carboxylic acid and with at least one saturated organic solvent and / or catalyst, treated with an ozone-containing or ozone-oxygen-containing gas mixture until 35 to 100% of the double bonds of the ozonated feedstock is reacted and subsequently cleaved thermally or thermally-catalytically with the interaction oxygen and / or after reacting 35-100% of the double bonds at a temperature of 50-130 ° C and treatment with oxygen-containing and / or ozone-containing gas, ozonization is carried out simultaneously followed by decomposition of the conjugated oxidation of the aldehyde groups formed to carboxyl and reaction product, as a rule, after treatment, the volatile fraction and / or malonic acid is separated, followed by hydrolysis and / or transesterification with formic acid associated with the separation of methanol and / or glycerol and / or methyl formate, wherein the mixture of monocarboxylic and dicarboxylic acids or esters thereof separated by processes such as distillation under normal or reduced pressure, water extraction and / or with at least one polar organic solvent, one-stage to four-stage extraction, thereby isolating at least a part of the carboxylic acids and extraction with water and / or at least one aliphatic and / or cycloaliphatic Azelaic acid is isolated in one to three extraction steps with a high oxygen compound selected from ketones, ethers, typically after separation of a substantial portion of pelargonic acid and other monocarboxylic acids and / or the reaction product is 85 to 100% after ozonation, ozonide decomposition and dooxidation. does not esterify with methanol and the mixture of monocarboxylic esters and dicarboxylic acid diesters obtained is separated by a known method. Process according to claim 1, characterized in that the mixture of predominantly unsaturated carboxylic acids is prepared by hydrolysis and / or saponification of vegetable oil and / or fish oil associated with the release of the carboxylic acids with a mineral acid. Method according to claims 1 and 2, characterized in that the mixture of glycerides of predominantly unsaturated carboxylic acids comprises at least one vegetable oil selected from oils of rapeseed, flax, hemp, soya, tung, sunflower, tall and / or fish oil selected from whale and herring. Process according to claims 1 to 3, characterized in that the mixture of methyl esters and / or free at least two unsaturated carboxylic acids is prepared by transesterification, hydrolysis or saponification associated with the release of the carboxylic acids of at least one fish and / or vegetable oil selected from the group. oils: rapeseed, flax, cotton, hemp, talc, soya, tung, sunflower, herring and whale. Process according to Claims 1 to 4, characterized in that the catalyst consists of at least one liquid mineral and / or carboxylic acid and / or a solid heterogeneous acid, wherein the solvent can also perform the function of an acid in the case of low molecular weight carboxylic acids. • I 6. The method of claims 1 to 5, characterized in that _x said catalyst is selected from the reaction medium-soluble carboxylic acid salts of transition metals, selected from among the salts of copper, manganese, cobalt and iron. 7. The method of claims 1 to 6, characterized in that the hydrolysis _± glycerides and / or ester is carried out with water and / or water vapor, at 160 ° to 300 ° C, preferably under the action of the hydrolysis catalyst and / or a phase transfer catalyst. 8. The method of claims 1 to 7, characterized in that before separation of the _± malonate all the operations, such as distillation, rectification, extraction, concentration, were carried out at below 140 ° C. Process according to claims 1 to 8, characterized in that the azelaic acid is isolated by extraction with the action of at least one aliphatic and / or cycloaliphatic ketone selected from acetone, methyl ethyl ketone, 1'-methylcyclopentanone, cyclohexanone and methylcyclohexanone. » Process according to claims 1 to 9, characterized in that the at least one ether as extracting agent is selected from diethyl ether, methyl tert-butyl ether, methyl tert-amyl ether and tetrahydrofuran.