Method of producing glutaric aldehyde

FIELD: chemistry.

SUBSTANCE: invention relates to a novel method of producing glutaric aldehyde. The method involves reaction, in a vessel at temperature of 80-120°C, of a reaction mixture containing an alkoxy dihydropyran derivative of formula I wherein R denotes a C1-C2 alkyl, water and an acid catalyst to obtain glutaric aldehyde and an alcohol, corresponding to the alkoxy group of alkoxy dihydropyran. Further, a distillation column is used to remove, from the reaction mixture, a distillate containing alcohol and unreacted alkoxy dihydropyran, followed by contacting the distillate with a heterogeneous catalyst lying outside the distillation column such that at least a portion of alkoxy dihydropyran reacts and returning at least a portion of the distillate into the distillation column.

EFFECT: method increases output of glutaric aldehyde.

8 cl, 3 dwg, 1 tbl

 

Cross-reference to related applications

This application claims the priority of patent application U.S. serial number 61/073885 filed June 19, 2008, the content of which is incorporated herein by reference.

The technical field

The invention relates to a method for glutaraldehyde.

The level of technology

Glutaric aldehyde get on an industrial scale by the hydrolysis of 2-methoxy-3,4-dihydro-2H-Piran (TIR) in the presence of an acid catalyst and water. The crude hydrolysis product is distilled to obtain the head stream of the methanol by - product of the reaction, which itself is suitable for recycling and use in other industrial processes, and tail products containing glutaric aldehyde in water. Glutaric aldehyde is an important chemical, which is used, for example, as a biocide, or for tanning leather.

In the known processes for the production of glutaraldehyde part of the unreacted starting material TIR removed by distillation, along with the side with methanol. Although the number of TIR is usually small, the presence of TIR in distilled methanol is undesirable for several reasons, including that the output of glutaric aldehyde is reduced due to loss of TIR, and that TIR is an impurity in the side methanol, which, as noted above, is a material which is suitable on which I re-use and useful in other industrial processes.

The invention is intended to eliminate the shortcomings of the current method of production of glutaraldehyde.

The invention

The invention provides a method of obtaining glutaraldehyde. The method includes:

(a) a reaction vessel at a temperature of from 80 to 120°C, the reaction mixture comprising alkoxystyrene formula I

in which R has a value of C1-C20alkyl,

water and an acid catalyst to obtain glutaric aldehyde and the alcohol corresponding to alkoxygroup alkoxystyrene;

(b) removing from the reaction mixture distillate comprising ethanol and unreacted derived alkoxystyrene in which the specified removal is performed with the use of distillation columns;

(c) contacting the distillate with a heterogeneous catalyst, outside the distillation column so that at least part of the derived alkoxystyrene reacts there; and

(d) returning at least part of the distillate stage (c) to a distillation column.

Brief description of drawings

Figure 1 is a schematic drawing of a typical variant of the design of the device, which can be used to perform the method according to the invention.

Figure 2 is a schematic drawing of the device, shows the surrounding accommodation of heterogeneous catalyst in various places.

Figure 3 is a schematic diagram of the apparatus for verification of the influence of location heterogeneous catalyst for the method of obtaining glutaraldehyde.

Detailed description of the invention

As noted above, the invention provides a method of obtaining glutaraldehyde. An important feature of the method according to the invention is the use of heterogeneous catalyst to efficiently hydrolyze unreacted alkoxypiperidine, which is carried away side alcohol during the distillation of alcohol from the reaction mixture with glutaraldehyde. The heterogeneous catalyst is placed outside the distillation column so that at least a portion of the distillate of the column could be contacted with the catalyst. When the hydrolysis alkoxystyrene in the flow of distillate way mainly increases the output of glutaraldehyde, and also provides side-alcohol, which is less contaminated by alkoxystyrene.

Distillation column for use in the invention is preferably a multi-disc setup, containing a sufficient number of theoretical plates (usually at least 2, more typically at least 20 plates)to cause the desired separation of glutaraldehyde and water from the side of alcohol.

According to the invention GHE is erogeny the catalyst may be located anywhere outside of the distillation column provided that at least a portion of the distillate from the column may be introduced into contact with him. For example, the catalyst may be located within the system reverse flow head flow is usually equipped with columns, such as the condenser, receiver condenser or line condensed stream flow. As a further example, the catalyst may be located next to the distillation column so that the flow of liquid or steam from any of the plates above the feed plate of the column could be passed through a heterogeneous catalyst and then returned to the column at the corresponding point. This point is usually the same plate as the plate selection, or one of the plates adjacent to the plate selection.

The location of the heterogeneous catalyst according to the invention and, in particular, when the catalyst is located in the area of reverse flow head flow distillation columns is advantageous because unreacted alkoxypiperidine relatively concentrated at this point, that, thereby, improves its ultimate conversion into glutaric aldehyde. It is important that when placing a heterogeneous catalyst, as described here, the advantage is achieved without significant formation of color in the product - glutaric the aldehyde. On the contrary, the placement of the catalyst within distillation the th column, especially in the lower sections of the distillation column, where there is a significant concentration of glutaraldehyde leads to polymerization of glutaraldehyde and color formation in the flow caused by the action of the catalyst on the glutaric aldehyde and similar components of the reaction mixture. The placement of the catalyst in the supply pipeline distillation column is also not preferable because of the possibility of the formation of color in the stream.

Heterogeneous catalyst is usually organic or mineral acid, which is fixed on a solid carrier. Holders of the acid should not significantly leach into the liquid stream flowing past it, and a solid carrier must be stable in the presence of fixed acid and liquid stream with which it contacts. Preferably apply granules resins, functionalityand acid (acidic ion-exchange resins are an example), or zeolites or clays, showing the acid functionality. Most preferred are acidic ion-exchange resin, such as Dowex MSC-1 (Dowex MSC-1, available from the Dow Chemical Company) and Amberlyst 15 (Amberlyst 15, available from Rohm & Haas). These preferred catalysts are particularly useful because they do not add significantly acid particles in flows in contact with them.

Heterogeneous is utilizator can be used in various forms, in order to facilitate the access of water to the catalyst. For example, the catalyst may be present in the tank, reactor or may be in the form of a catalyst layer, filter or suspension. Whatever the form, it must provide sufficient contact between the current flow and the catalyst. Preferably use a tank or reactor having a liquid distributor at the inlet of the stream and filled or partially filled with a heterogeneous catalyst, and then filter or sieve device to prevent the leakage of heterogeneous catalyst from the reactor together with the stream, which is returned to the distillation column.

The number of heterogeneous catalyst, it is desirable for the invention depends on several factors and can be easily determined by the expert in the technology. The factors include: 1) the residence time or contact time of the current of liquid and catalyst; 2) the temperature of the liquid and, consequently, of the catalyst; and 3) the concentration of acid sites of the catalyst, often expressed as the number of milliequivalents per cubic centimeter of volume of resin. Here is a non-limiting example: for a resin having a pH from 0.1 to 2 milliequivalent/cm3layer resin a typical residence time within the catalyst layer can be 10 seconds or more, and the typical temperature is about Atego flow downstream of the flow can be from 40 to 60°C.

The method according to the invention are useful for glutaraldehyde derived from alkoxystyrene formula I

in which R has a value of C1-C20alkyl. Preferably, R has a value of C1-C6alkyl, more preferably C1-C3alkyl. Most preferably, R has a value of methyl (the compound is therefore 2-methoxy-3,4-dihydro-2H-Piran (TIR)). In the case of TIR side alcohol is methanol.

To get glutaric aldehyde, alkoxypiperidine formula I hydrolyzing with water in the presence of an acid catalyst. In addition to the formation of glutaric aldehyde in the reaction also produces alcohol of the formula R-OH as a side product. The type of vessel used for the reaction is not important. In a preferred embodiment, the design of the reactor equipped with a stirrer with a Central shaft driven by the engine, and is divided into one or more sections, which act as "mixing continuous action" (CSIR). The reaction is performed at a temperature of from 80 to 120°C, more preferably from 95 to 110°C. the reaction Time is from about 1 to 24 hours, more typically from about 1 to 3 hours.

Various acid catalysts can be used for hydrolysis in the mass, including the content of inorganic fillers acid, such as saturated and unsaturated carboxylic acids having from 1 to 10 carbon atoms or a multifunctional acids such as maleic acid. Preferably used mineral acids such as phosphoric acid, boric acid, nitric acid, sulfuric acid or acidic salt, such as NaH2PO4. Phosphoric acid is particularly preferred. In addition to providing the appropriate acid strength for effective catalysis of the reaction of phosphoric acid also generates a buffer of pH, being partially neutralized by a neutralizing agent such as sodium bicarbonate. Buffer pH~4 stabilizes glutaric aldehyde product. The amount of acid catalyst should be such that the concentration of acid in the reactor was in the range of from 0.01 to about 0.2 wt.%. Generally, the acid catalyst is mixed with water to approximately the concentration of 0.1 wt.% and serves together with the derived alkoxystyrene in the reactor. Other solvents can be used in addition to water or instead of water, such as alcohol, alkoxypiperidine or a mixture of glutaric aldehyde-water. Further, additional water may be added preferably in an amount such that the glutaric aldehyde was obtained in the desired concentration with subsequent removal of the alcohol after the reaction. Site is citicoline concentration of glutaraldehyde is from 5 to 75 wt.%, more preferably from 25 to 65 wt.%.

A typical implementation of the method according to the invention in operation is illustrated in figure 1. Refer now to figure 1, alkoxypiperidine and water along with an acid catalyst, with the catalyst preferably pre-mixed with water or part of the water to obtain a solution, is injected from one end of the reactor 10, with few interior walls, transforming it in CSIR. The reactor 10 further has a Central shaft 20 with blades 30 and the motor 40. The reactor is preferably operated at an elevated temperature, such as from 80 to 120°C, more preferably from about 95 to 110°C. After approximately 1-2 hours reaction time the exit stream from the reactor is transferred to a multi-disc distillation column 60 by applying pressure or by pumping through the line 50. The capacity of the intermediate storage may also be submitted on line 50. Within multi-disc distillation column side alcohol and, as noted above, a small number alkoxystyrene (usually 2 wt.% or less) is separated from the product glutaric aldehyde/water and removed from the system as distillate 80. Enriched with methanol distillate 80 condense in the condenser 90 and then, at least, part of it is introduced into contact with the heterogeneous Katalizator the 70, in a typical embodiment, is located on the line of the reverse flow head flow distillation columns. In this typical embodiment, the boiler distillation columns for the evaporation of the liquid to be returned to a distillation column, shown as 100. The thread tails glutaric aldehyde-water (cube) is shown as 110.

The contacting portion of the distillate stream 80, which is returned to the distillation column (reverse flow), with a heterogeneous catalyst 70 leads to the fact that at least part of the unreacted alkoxystyrene in the distillate 80 reacts with the side alcohol or water in the stream. The reaction with water is formed directly glutaric aldehyde. Glutaric aldehyde produced thereby increases the total yield of the product. Glutaric aldehyde or alkoxypiperidine usually also react with alcohol in the presence of a catalyst with the production of other materials such as dialkoxybenzene (as well as acetals, hemiacetals, aldehydes etc). Dialkoxybenzene materials are moved to the cube of the column due to its higher boiling point and hydrolyzed with the formation of additional amounts of glutaraldehyde and alcohol below the supply of plates in the column, where there is a mixture of acid and water, thus further increasing vyhodjawaja aldehyde.

Glutaraldehyde waste materials can be used without further processing, or they can be partially neutralized by a base, such as sodium hydroxide, sodium bicarbonate or sodium carbonate to bring the pH of the stream to the desired value, such as 3-5, to increase the stability of the cubic flow. Can be added to water or other ingredients to produce different compositions of glutaraldehyde, if desired.

The following examples illustrate the invention but are not intended to limit its scope.

EXAMPLES

Total

Examples compare the placement of a heterogeneous catalyst at two different locations relative to the distillation column used for separation of alcohol from the reaction mass. Tested locations shown in figure 2. "B" represents the location of a heterogeneous catalyst according to the invention. "A" represents the location is not according to the invention, used for comparative purposes.

Laboratory instrument for modeling the impact of placing a heterogeneous catalyst is used in the examples and shown in figure 3. As shown, glass 200 column (inner diameter 1.5 cm to about 25 cm length)with a Teflon adapter (from the speakers to the receiver 0,32 cm) at each end, filled with glass pellets (3 mm) with boih ends as the inert carrier, and the center section is filled with an acidic ion-exchange resin catalyst. The column is immersed in a thermostated water bath and mix 210. The flow of liquid in the column to provide an adjustable peristaltic pump 220. The supply line 230 is made from a tube of 0.32 cm 316 stainless steel in the form of a coil immersed in a water bath to heat the fluid before entering the column. Teflon tube 0,32 cm 240 are used for output flow of product to distribute the product in the sample container or container for storage, if desired. The entire volume of the channel currents from the beginning of the catalyst layer to the end of the discharge tube is approximately 20 ml. After changing the feed speed is produced, the system has been up until at least 40 ml of feed material (approximately two channel volume flow equipment) will not be processed before produce sampling to ensure that the sampling of the product corresponds exactly to this flow rate. This test, producing a sampling experience in two different time periods, divided by the time required for at least another 20 ml of the feed material were recycled. If the two samples do not give a close analytical journal the results, the time interval between sampling increases until the sample really does not give close results. In these examples, Carnet used as alkoxystyrene (side alcohol is methanol).

When testing point And (2) the purpose of the catalytic layer of the resin is to convert as many TIR glutaric aldehyde as possible. A typical composition of the feed material, tested at this point, is about 14 wt.% MeOH, 42 wt.% glutaraldehyde, 42 wt.% water and 2 wt.% TIR.

When testing point (figure 2) catalytic layer resin should hydrolyze a number of TIR in glutaric aldehyde, and the rest of the TIR dialkoxybenzene isomers 2,6-dimethoxymethyl-2H-Piran (both referred to here as DMTP). A typical composition of the feed material, tested in this paragraph is about 96 wt.% MeOH, 2 wt.% water and 2 wt.% TIR.

First studied heterogeneous catalytic resin is Amberlyst 15-W (Rohm & Haas Amberlyst 15-W). This resin is a strongly acidic, macrostate polymer resin granules containing sulfonylurea group, in aqueous and nonaqueous systems. W indicates that the resin purchased in a hydrophilic state. The second resin, Dowex M-31 (Dowex™ M-31), such Amberlist 15-W (strongly acidic, macrostate polymer Smolov granules, containing sulfonylurea group, in aqueous and nonaqueous systems). The third studied the resin is a resin Dowex™ MAC (acid, macrostate polymer resin granules containing carboxylic acid groups, in aqueous and nonaqueous systems). Resin Dowex MAC include, to determine whether "weak" acid resin differently than the strong acid catalysts, especially at the point A.

To simulate temperature installation, test point And is carried out at a temperature of 90-93°C, and the tests point To spend at 41°C.

Gas chromatography (GC) is used to explore the outflows of each experiment.

Discussion: experiments on point And

It was found that the experiments at point a with a strongly acidic catalysts (Amberlist 15-W or Dowex M-31), as found, quickly convert TIR, but produce a rapid staining fluid. The resin also becomes a dark color after only a few hours. Increasing the feed rate to reduce the residence time in the catalyst bed, reduces the level of staining fluid, but not as sharply as desirable. The required time of stay in the layer is less than 50 seconds, but even then, the resin quickly changes color and becomes visible staining.

Gas chromatographic analysis shows that the peak TIR significantly reduced and formed several new the x peaks. Some of these peaks installed using gas chromatography/mass spectrometry as the corresponding compounds 5,5-dimethoxyphenyl-1-al (acetal) and 1,1,5,5-tetramethoxybenzene (diacetyl).

The use of resin Dowex MAC with the "weaker" carboxylic acid functional groups, reduces the appearance of color formation, and less effective in the catalysis of the conversion of TIR in DMTP.

Discussion: the experimental point B

In these experiments we studied the placement of a heterogeneous catalyst at point B. Skip to 2 wt.% TIR and 2 wt.% water in methanol flux through a 10.6 cm3the layer of resin Dowex M-31 at 41°C. the Material, after passing through the catalyst bed, analyze by gas chromatography. Samples of the reaction product taken at different flow rates. This feed rate corresponds to the hourly flow rate (Czos; where CIOs defined as the volumetric flow rate per hour/volume of catalyst layer; that is, the gallons of feed per hour/gallon of resin, which gives the unit: h-1in the range from 5.7 to 56.6 h-1. Using the calculation of the peak area of TIR in each chromatogram can be used to determine the percent conversion TIR depending on CIOs. The data presented in Table 1.

Table 1/td>
Hourly space velocity, CIOs (h-1)=60 * flow Velocity (cm3/min) / Volume of catalyst, where the catalyst layer = Volume of resin + empty Volume = Total occupied space (cm3).

It is important that under all conditions tested on laboratory equipment, no education color did not occur when the acid catalyst was placed at the point B.

Complete conversion TIR glutaric aldehyde is not required at the point B, because most of the unreacted TIR will pass through the layer again. For example, if the coefficient reflux distilled 3,75% this MOS will be returned to the reactor with reverse flow, assuming no conversion of the TIR does not occur within the column. The higher the ratio of reflux distilled, the less effective a single conversion (conversion per pass) TIR.

While the invention has been described above according to its preferred options for implementation, it can be changed within the essence and scope of the invention. This application is therefore intended to cover any changes, use or adaptation of the invention, using the General principles disclosed here is. Next, the application is intended to cover such departures from existing inventions that are within known or customary practice in the technology to which this invention relates, and which fall within the scope of the following claims.

1. The method of obtaining glutaraldehyde, including:
(a) a reaction vessel at a temperature from 80°C to 120°C the reaction mixture containing the derived alkoxystyrene formula I

in which R has a value of C1-C20alkyl, water and an acid catalyst, to obtain the glutaric aldehyde and the alcohol corresponding to alkoxygroup alkoxystyrene;
b) removing from the reaction mixture distillate containing alcohol and unreacted alkoxypiperidine, in which the indicated deletion produced using distillation columns;
c) contacting the distillate with a heterogeneous catalyst, outside the distillation column, so that reacts at least a portion alkoxystyrene; and
d) returning at least part of the distillate stage (c) to a distillation column.

2. The method according to claim 1, wherein the distillation column is equipped with reverse flow head flow, including the condenser, receiver condenser and condensed the CSOs reverse flow head flow, and the heterogeneous catalyst is placed in the reverse flow head flow.

3. The method according to claim 2, in which the heterogeneous catalyst is placed in line condensed reverse flow head flow.

4. The method according to claim 2, in which the heterogeneous catalyst is placed in the receiver of the condenser.

5. The method according to any one of claims 1 to 4, in which derived alkoxystyrene is 2-methoxy-3,4-dihydro-2H-Piran.

6. The method according to any one of claims 1 to 4, in which the heterogeneous catalyst are resin beads, functionalized acid, zeolites or clay.

7. The method according to any one of claims 1 to 4, in which the heterogeneous catalyst is an acidic ion-exchange resin.

8. The method according to any one of claims 1 to 4, in which R in formula I is a is methyl.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing high-purity polyethylene glycol-aldehyde compounds of general formula OHC-(CH2)k-1-O-(CH2CH2O)n-(CH2)k-1CHO. The method of producing said compounds is realised by reacting a polyethylene glycol derivative of formula: HO-(CH2)k-O-(CH2CH2O)n-(CH2)k-OH, with dimethylsulphoxide and dicyclohexylcarbodiimide.

EFFECT: method of producing polyethylene glycol-aldehyde compounds is cheap and said compounds can be used to improve solubility and efficiency of medicinal substances owing to binding thereto without impurities.

11 cl, 3 ex

FIELD: process engineering.

SUBSTANCE: invention relates to electrodialysis cleaning of water solution of glyoxal in electrodialysis apparatus with cation- and ion-exchange membranes. Proposed method comprises said solutions through set of electrodialysis cells, each containing three ion-exchange membranes. Said water solution of glyoxal is processed by dry NaOH to pH of 3 to 6.5, while electrodialysis is conducted using pulse current with pulse frequency of 50 to 103 Hz. One of ion-exchange membranes is composite and features relationship between areas of membrane ion- and cation-exchange parts varying from 1:1 to 6:1.

EFFECT: three- to fivefold decrease in power consumption, higher yield of target product.

1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for synthesis of glyoxal in form of an aqueous solution containing 40 ± 1.5 or 30 ± 0.8 wt % glyoxal which can be used as an emulsifier, bacterial inhibitor, flocculant, preservative, solvent etc. The method involves oxidative dehydrogenation of monoethylene glycol on a domestically produced industrial silver catalyst deposited on aluminosilicate, containing 32-36 wt % silver of the D-53M type, and involves the following successive steps: preparation of a 40-50 wt % aqueous solution of monoethylene glycol on distilled water or steam condensate; preparation of initial reaction mixture by mixing air or nitrogen-air mass, heated in an electrical heater to 260°C or above, and a water-glycol vapour phase obtained in an evaporator and superheated in a "hardening" apparatus using heat of the oxidation reaction mass, taken in respective molar ratios: monoethylene glycol O2=1.0:1.0-1.1; monoethylene glycol: N2=1.0:4.36-7.0; - synthesis of glyoxal in a single- or multiple-shell reactor operating in adiabatic mode, on a catalyst layer at temperature 540-620°C, atmospheric pressure and specific input of ethylene glycol of 1.70-2.3 g/cm3 cat·h; - strengthening of the oxidate (synthesis reaction mass) which is raw glyoxal through vacuum stripping at temperature not above 52°C and residual pressure of 100 mm Hg to obtain commercial grade product containing 40 ± 1.5 or 30 ± 0.8 wt % glyoxal.

EFFECT: proposed method can be used in industrial production.

2 dwg

FIELD: chemistry.

SUBSTANCE: catalyst for glyoxal synthesis includes silicon-containing silver carrier and silver as active component, as silicon-containing carrier silicate with open pores is used. Ion-conducting modifier, in amount 0.5÷50.0% of catalyst weight, is introduced into silicate pores, silver with particle size 1÷200 nm in amount 1.0÷10.0% of catalyst weight is placed in pore mouths on outer surface of carrier. Also described is method of glyoxal synthesis, including oxidation of ethylene glycol with oxygen, which is in mixture of air with inert gas and water vapours, on silver catalyst at temperature from 450 to 800°C, ethylene glycol oxidation being carried out with reaction mixture, in which molar ratio of oxygen to ethylene glycol is set in interval from 0.7:1.0 to 2.0:1.0, using described above catalyst.

EFFECT: increase of selectivity of ethylene glycol oxidation process, increase of catalyst service term, increase of its heat resistance and reduction of silver consumption for catalyst preparation.

2 cl, 2 tbl, 4 dwg, 10 ex

FIELD: chemical technology.

SUBSTANCE: invention relates to a method for continuous synthesis of glyoxal-containing products of the desired concentration in a single-step technological cycle. Method involves vapor-phase catalytic process of partial oxidative dehydrogenation of ethylene glycol with oxygen diluted with steam and nitrogen in the mole ratio from 1/6.5 to 1/13.0 at temperature 400-700°C on carrier Ag-contacts and massive Ag-catalysts made of materials of electrolytic origin of particles size 0.1-4.0 mm. Then the process involves continuous the vat-less separation of vapor-gaseous oxidate for liquid fractions and gaseous phase wherein prepared aqueous aldehyde solutions contain 4-40% of glyoxal, 6.2% of glycolic aldehyde, not above, 4.6% of formaldehyde, not above, 4.0% of ethylene glycol, not above, at the total acidity index 2%. The end product comprises 39.8% of glyoxal, 5.5% of glycolic aldehyde and 0.4% of formaldehyde. The process of continuous the vat-less separation of synthesis products for glyoxal-containing liquid fractions and depleted gaseous phase is carried out continuously in the range of temperature 10-400°C as result of subcontact cooling in combination with three-step combined condensation of components of vapor-gaseous oxidate in a cascade block-unit in fractional isolation of liquid and gaseous products of synthesis, and in regulation of heat regimen of the combined condensation and change of the ratio of liquid fractions.

EFFECT: improved method of synthesis.

1 dwg, 13 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to compounds of polyethylene glycol aldehyde (PEG-aldehydes), to method for synthesis of indicated compounds of polyethylene aldehyde, and to intermediate compounds that are used in synthesis of PEG-aldehydes. Method for synthesis of PEG-aldehydes involves pyrolysis of indicated intermediate substances. Indicated aldehydes of polyethylene glycols represent specific reagents for formation of PEG-peptides and other biomolecules by N-terminal amino acid residues, i. e. PEG-aldehydes form conjugate with N-terminal α-amino-group of biomolecule or protein with formation of a stable bond as secondary amine between PEG and biomolecule or protein. Also, in PEG-polypeptides the specific N-terminal bond is formed that excludes formation of cross-linking bonds or formation of some derivatives of the same polypeptide. Depending on chosen aldehyde PEG can bind covalently with biomolecule by one terminal group (monofunctional PEG-aldehyde) or by two terminal groups (bifunctional PEG-aldehyde). The advantage of PEG conjugates with biomolecules involves their enhanced retaining and delayed metabolism in body.

EFFECT: improved preparing method, improved and valuable properties of compounds.

17 cl, 7 ex

FIELD: industrial organic synthesis catalysts.

SUBSTANCE: invention provides catalyst for production of glyoxal via catalytic oxidation of ethylene glycol, wherein lower catalyst bed is composed of crystalline copper, upper bed of fibrous silver granules, and the two beds are modified with phosphorus. Crystalline copper particles are 1 to 100 μm in pore size and 5 to 50 μm in wall thickness. Fibrous silver granules are 0.01 to 3.00 mm in size with their specific surface being between 0.10 and 0,17 m2/g. Surface concentration of phosphorus is between 0.1 and 6% for lower bed and between 0.05 and 3.00% for upper one.

EFFECT: increased conversion and selectivity of ethylene glycol oxidation process and simplified catalyst bed formation.

4 cl, 4 ex

The invention relates to organic chemistry and can be used for industrial production of glycol by a vapor-phase catalytic oxidation of ethylene glycol

The invention relates to the field of organic synthesis, in particular the production of glyoxal, which is used in the manufacture of polymers, insecticides and pharmaceuticals, as well as in leather, fur and textile industries

FIELD: chemistry.

SUBSTANCE: invention relates to a novel method of producing glutaric aldehyde. The method involves reaction, in a vessel at temperature of 80-120°C, of a reaction mixture containing an alkoxy dihydropyran derivative of formula I wherein R denotes a C1-C2 alkyl, water and an acid catalyst to obtain glutaric aldehyde and an alcohol, corresponding to the alkoxy group of alkoxy dihydropyran. Further, a distillation column is used to remove, from the reaction mixture, a distillate containing alcohol and unreacted alkoxy dihydropyran, followed by contacting the distillate with a heterogeneous catalyst lying outside the distillation column such that at least a portion of alkoxy dihydropyran reacts and returning at least a portion of the distillate into the distillation column.

EFFECT: method increases output of glutaric aldehyde.

8 cl, 3 dwg, 1 tbl

FIELD: industrial organic synthesis catalysts.

SUBSTANCE: invention provides catalyst for production of glyoxal via catalytic oxidation of ethylene glycol, wherein lower catalyst bed is composed of crystalline copper, upper bed of fibrous silver granules, and the two beds are modified with phosphorus. Crystalline copper particles are 1 to 100 μm in pore size and 5 to 50 μm in wall thickness. Fibrous silver granules are 0.01 to 3.00 mm in size with their specific surface being between 0.10 and 0,17 m2/g. Surface concentration of phosphorus is between 0.1 and 6% for lower bed and between 0.05 and 3.00% for upper one.

EFFECT: increased conversion and selectivity of ethylene glycol oxidation process and simplified catalyst bed formation.

4 cl, 4 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to compounds of polyethylene glycol aldehyde (PEG-aldehydes), to method for synthesis of indicated compounds of polyethylene aldehyde, and to intermediate compounds that are used in synthesis of PEG-aldehydes. Method for synthesis of PEG-aldehydes involves pyrolysis of indicated intermediate substances. Indicated aldehydes of polyethylene glycols represent specific reagents for formation of PEG-peptides and other biomolecules by N-terminal amino acid residues, i. e. PEG-aldehydes form conjugate with N-terminal α-amino-group of biomolecule or protein with formation of a stable bond as secondary amine between PEG and biomolecule or protein. Also, in PEG-polypeptides the specific N-terminal bond is formed that excludes formation of cross-linking bonds or formation of some derivatives of the same polypeptide. Depending on chosen aldehyde PEG can bind covalently with biomolecule by one terminal group (monofunctional PEG-aldehyde) or by two terminal groups (bifunctional PEG-aldehyde). The advantage of PEG conjugates with biomolecules involves their enhanced retaining and delayed metabolism in body.

EFFECT: improved preparing method, improved and valuable properties of compounds.

17 cl, 7 ex

FIELD: chemical technology.

SUBSTANCE: invention relates to a method for continuous synthesis of glyoxal-containing products of the desired concentration in a single-step technological cycle. Method involves vapor-phase catalytic process of partial oxidative dehydrogenation of ethylene glycol with oxygen diluted with steam and nitrogen in the mole ratio from 1/6.5 to 1/13.0 at temperature 400-700°C on carrier Ag-contacts and massive Ag-catalysts made of materials of electrolytic origin of particles size 0.1-4.0 mm. Then the process involves continuous the vat-less separation of vapor-gaseous oxidate for liquid fractions and gaseous phase wherein prepared aqueous aldehyde solutions contain 4-40% of glyoxal, 6.2% of glycolic aldehyde, not above, 4.6% of formaldehyde, not above, 4.0% of ethylene glycol, not above, at the total acidity index 2%. The end product comprises 39.8% of glyoxal, 5.5% of glycolic aldehyde and 0.4% of formaldehyde. The process of continuous the vat-less separation of synthesis products for glyoxal-containing liquid fractions and depleted gaseous phase is carried out continuously in the range of temperature 10-400°C as result of subcontact cooling in combination with three-step combined condensation of components of vapor-gaseous oxidate in a cascade block-unit in fractional isolation of liquid and gaseous products of synthesis, and in regulation of heat regimen of the combined condensation and change of the ratio of liquid fractions.

EFFECT: improved method of synthesis.

1 dwg, 13 ex

FIELD: chemistry.

SUBSTANCE: catalyst for glyoxal synthesis includes silicon-containing silver carrier and silver as active component, as silicon-containing carrier silicate with open pores is used. Ion-conducting modifier, in amount 0.5÷50.0% of catalyst weight, is introduced into silicate pores, silver with particle size 1÷200 nm in amount 1.0÷10.0% of catalyst weight is placed in pore mouths on outer surface of carrier. Also described is method of glyoxal synthesis, including oxidation of ethylene glycol with oxygen, which is in mixture of air with inert gas and water vapours, on silver catalyst at temperature from 450 to 800°C, ethylene glycol oxidation being carried out with reaction mixture, in which molar ratio of oxygen to ethylene glycol is set in interval from 0.7:1.0 to 2.0:1.0, using described above catalyst.

EFFECT: increase of selectivity of ethylene glycol oxidation process, increase of catalyst service term, increase of its heat resistance and reduction of silver consumption for catalyst preparation.

2 cl, 2 tbl, 4 dwg, 10 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for synthesis of glyoxal in form of an aqueous solution containing 40 ± 1.5 or 30 ± 0.8 wt % glyoxal which can be used as an emulsifier, bacterial inhibitor, flocculant, preservative, solvent etc. The method involves oxidative dehydrogenation of monoethylene glycol on a domestically produced industrial silver catalyst deposited on aluminosilicate, containing 32-36 wt % silver of the D-53M type, and involves the following successive steps: preparation of a 40-50 wt % aqueous solution of monoethylene glycol on distilled water or steam condensate; preparation of initial reaction mixture by mixing air or nitrogen-air mass, heated in an electrical heater to 260°C or above, and a water-glycol vapour phase obtained in an evaporator and superheated in a "hardening" apparatus using heat of the oxidation reaction mass, taken in respective molar ratios: monoethylene glycol O2=1.0:1.0-1.1; monoethylene glycol: N2=1.0:4.36-7.0; - synthesis of glyoxal in a single- or multiple-shell reactor operating in adiabatic mode, on a catalyst layer at temperature 540-620°C, atmospheric pressure and specific input of ethylene glycol of 1.70-2.3 g/cm3 cat·h; - strengthening of the oxidate (synthesis reaction mass) which is raw glyoxal through vacuum stripping at temperature not above 52°C and residual pressure of 100 mm Hg to obtain commercial grade product containing 40 ± 1.5 or 30 ± 0.8 wt % glyoxal.

EFFECT: proposed method can be used in industrial production.

2 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to electrodialysis cleaning of water solution of glyoxal in electrodialysis apparatus with cation- and ion-exchange membranes. Proposed method comprises said solutions through set of electrodialysis cells, each containing three ion-exchange membranes. Said water solution of glyoxal is processed by dry NaOH to pH of 3 to 6.5, while electrodialysis is conducted using pulse current with pulse frequency of 50 to 103 Hz. One of ion-exchange membranes is composite and features relationship between areas of membrane ion- and cation-exchange parts varying from 1:1 to 6:1.

EFFECT: three- to fivefold decrease in power consumption, higher yield of target product.

1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing high-purity polyethylene glycol-aldehyde compounds of general formula OHC-(CH2)k-1-O-(CH2CH2O)n-(CH2)k-1CHO. The method of producing said compounds is realised by reacting a polyethylene glycol derivative of formula: HO-(CH2)k-O-(CH2CH2O)n-(CH2)k-OH, with dimethylsulphoxide and dicyclohexylcarbodiimide.

EFFECT: method of producing polyethylene glycol-aldehyde compounds is cheap and said compounds can be used to improve solubility and efficiency of medicinal substances owing to binding thereto without impurities.

11 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a novel method of producing glutaric aldehyde. The method involves reaction, in a vessel at temperature of 80-120°C, of a reaction mixture containing an alkoxy dihydropyran derivative of formula I wherein R denotes a C1-C2 alkyl, water and an acid catalyst to obtain glutaric aldehyde and an alcohol, corresponding to the alkoxy group of alkoxy dihydropyran. Further, a distillation column is used to remove, from the reaction mixture, a distillate containing alcohol and unreacted alkoxy dihydropyran, followed by contacting the distillate with a heterogeneous catalyst lying outside the distillation column such that at least a portion of alkoxy dihydropyran reacts and returning at least a portion of the distillate into the distillation column.

EFFECT: method increases output of glutaric aldehyde.

8 cl, 3 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of purification of glyoxal water solution by successive running of purified solution through electrodialyser chambers, separated with anion-exchange and cation-exchange membranes. Purification is performed by asymmetric alternating current of controlled frequency with the following parameters: frequency f=5-2000 Hz, voltage Um=0.1-500 V, ratio of direct and reverse current Jmn:Jm0=2:112:1, with water solutions of alkali metals, ammonium carbonates or ammonium bicarbonates serving as collectors of admixtures in purification of glyoxal water solutions, and rate of solutions constitutes from 0.001 to 100 m/s. Invention also relates to device for purification of glyoxal water solutions.

EFFECT: method makes it possible to increase process selectivity and makes it possible to carry out purification of highly concentrated glyoxal solutions.

2 cl, 2 dwg, 1 tbl, 2 ex

FIELD: technological processes.

SUBSTANCE: present invention relates to a continuous method of producing glyoxal by oxidation of ethylene glycol with atmospheric oxygen in a mixture with recirculating inert gas on a catalyst containing silver. Recirculating gas used as a diluent and ethylene glycol solution entering reactor are successively pre-heated by heat generated during oxidation of ethylene glycol at catalyst, and cooling of reaction products is performed in successively by their irrigation with cooled solution of glyoxal in a zone lying immediately behind catalyst layer and in tubular sub-contact 2-sectional heat exchanger, in lower section of which ethylene glycol is heated, and in upper section - heating of recirculating gas used as a diluent.

EFFECT: proposed method enables to obtain an end product with high output.

7 cl, 3 dwg, 1 tbl, 3 ex

Up!