Method of obtaining methacrylated benzophenones

FIELD: chemistry.

SUBSTANCE: invention relates to a method of obtaining benzophenone (meth)acrylates, in which contact of hydroxybenzophenones and (meth)acrylic acid is realised in the presence of catalytic quantities of concentrated sulphuric acid, alkyl- or arylsulphonic acid with the following neutralisation of the catalyst and further purification of the raw monomer.

EFFECT: method makes it possible to achieve high degrees of conversion, which leads to the considerable reduction of quantity of byproducts.

5 cl, 4 ex

 

The invention relates to a method for metakrilovyh of benzophenone.

The prior art describes a method for the aforementioned esters using anhydride methacrylic acid (the Japan patent 2003261506, Mitsubishi Rayon). As the catalyst used triethylamine. Since the amine forms a salt resulting from the reaction of methacrylic acid, it is necessary to take in equimolar amounts based on benzophenone. In accordance with this get equimolar amount of salt that should be processed as waste production. For this reason, this method is uneconomical.

Other relevant prior art ways presents the interaction between the acid chloride and methacrylic acid containing a hydroxyl group, a benzophenone, and the interaction of these original products with glycidylmethacrylate. When working with the acid chloride and methacrylic acid should take into account its corrosive and corrosive properties. In addition, upon contact with water, it produces hydrogen chloride.

In the Federal Republic of Germany patent No. 1720603 described a method of obtaining a water dispersion of polymerization products that can easily form a mesh structure. To do this, hold the copolymerization acyl and methacrylate esters with activated light olefinic unsaturated mono the apostrophes, if necessary, the copolymerization is carried out with the use of activated light nonionic emulsifiers.

European patent No. 0346788 relates to a method for obtaining sensitive to the action of light carbamoylated - and-acetophenone with at least one methacrylate or acrylate end group. In doing so, the interaction isocyanatomethyl(meth)acrylates with hydroxyacetophenone or hydroxybenzophenone in the presence of a basic catalyst. Such work should be carried out with the exclusion of the possibility of contact with moisture. In addition, you can only use dried dinucleophiles solvents.

The goal was to develop an improved method of producing esters of (meth)acrylic acid and benzophenone with hydroxyl functional groups.

The task is solved by a method for production of benzophenone(meth)acrylates, which differs in that hydroxybenzophenone anhydride and (meth)acrylic acid interact in the presence of catalytic amounts of acid, the catalyst is neutralized and then spend the purification of the crude monomer.

If you write (meth)acrylate, in this case, it refers to methacrylate such as methyl methacrylate, ethyl methacrylate, etc., and acrylate, such as methyl acrylate, acrylate and so on, and so is e to mixtures of such esters.

Unexpectedly, it was found that corresponds to the invention method allows to achieve high degrees of conversion that leads to a significant reduction in the number of by-products. It was shown that by implementing the invention method produces only a small amount of salts, which are products of neutralization used as the acid catalyst in the processing. Formed as a by-product of methacrylic acid can be used as co monomer with the following further polymerization benzophenone monomer or it can be returned to the process for obtaining a new party anhydride methacrylic acid.

The interaction can be performed in the presence of normal alkyl - or arylsulfonyl, but preference is given to using sulphuric acid.

In the preferred case 4-hydroxybenzophenone anhydride and (meth)acrylic acid react in the presence of catalytic amounts of concentrated sulfuric acid.

Anhydride (meth)acrylic acid take in a small excess in relation to hydroxybenzophenone. The interaction occurs at a temperature in the range from 50 to 120°C, in the preferred case from 80°C to 100°C, during the time from 4 to 8 hours, in the preferred case from 5.5 to 6.5 hours.

Neutralization of modulating isomaltase as the catalyst acid is carried out using an aqueous bases, in the preferred case, the solution of the hydroxide of an alkali metal or ammonia.

Following this, the processing of the raw monomer is conducted by adding water. When this occurs, the dissolution of impurities, thereby facilitating their separation. Water-soluble impurities in the melt benzophenone(meth)acrylate in the preferred case, remove the addition of water.

Benzophenone(meth)acrylate precipitated from the reaction mixture by the addition of excess water and separating it by filtration in the form of solids.

The resulting benzophenone(meth)acrylates of high purity can be stored in the form of a solution in methyl methacrylate, n-butylmethacrylate, isobutylacetate or styrene and apply them in the following transformations.

Benzophenone(meth)acrylates can be applied to subsequent photoinitiated education reticulated structure in the polymer under the action of daylight or UV radiation, as well as polymer photoinitiator.

Benzophenone(meth)acrylates can also be used as comonomers in the polymerization reactions.

The following examples are intended to further illustrate the present invention, and they may not serve as a basis for restricting the scope of the claims presented in their characteristics.

Examples

Example 1

Equipment used: chetyrehkolka round-bottom flask with a volume of 4 liters with a mechanical stirrer, reflux condenser, temperature sensor Pt100, tube to enter the air nozzle Anshutz, addition funnel, an oil bath with electric heating.

Download:

to 3.5 mol of 4-hydroxybenzophenone, 99,7%, 695,9 g,

of 3.85 mol of anhydride methacrylic acid (stabilized by the addition of 2000 ppm of 2,4-dimethyl-6-tert-butylphenol), 618,4 g,

at 0.020 mol of concentrated sulfuric acid, 1,99 g,

1864 mg nanometrology ether of hydroquinone,

932 mg 2,4-demethyl-6-tert-butylphenol.

The catalyst is neutralized by addition of 1.8 g of sodium hydroxide dissolved in 10 g of water.

The excess anhydride methacrylic acid etherification the addition of 22.4 g of methanol.

Theoretical output 930,0,

The experiment:

Weigh and load all the components of the reaction mixture and then with stirring and while passing air heated to 90°C. the reaction Time at 90°C is 6 hours. Then cooled to about 60°C and add the dissolved sodium hydroxide for neutralization used as a catalyst, sulfuric acid, and methanol for the esterification neprevyshenie anhydride methacrylic acid. Then stirred for 1 hour at 60°C and then pour in reactio the percent mass trickle in 3 liters of water while stirring (metal propeller stirrer, motor for mixing). Stirred for 0.5 hour and the precipitation is filtered through a porous glass filter 2 more times washed with water to 2 liters and then dried precipitate on the filter by passing air. Then dry the solid in the air.

Output 924,5 g (99.4% of theory).

Analysis: the water content of 0.08%,

6 parts per million nanometrology ether of hydroquinone,

174 ppm of 2,4-dimethyl-6-tert-butyl-phenol.

Data gas chromatographic analysis:

0,047% of methyl methacrylate,

0,013% of methacrylic acid,

0,637% 4-hydroxybenzophenone,

97,56% 4-(methacryloyloxy)benzophenone.

The color on the platinum-cobalt scale in the form of a 20% solution in acetone 150.

Example 2

Equipment used: chetyrehkolka round-bottom flask with a volume of 4 liters with a mechanical stirrer, reflux condenser, temperature sensor Pt100, tube to enter the air nozzle Anshutz, addition funnel, an oil bath with electric heating.

Download:

a 1.5 mol of 4-hydroxybenzophenone, 303,

of 1.65 mol of anhydride methacrylic acid (stabilized by the addition of 2000 ppm of 2,4-dimethyl-6-tert-butylphenol), 262 g,

0,0087 mole of concentrated sulfuric acid, 0.84 g,

798 mg nanometrology ether of hydroquinone,

399 mg of 2,4-dimethyl-6-tert-butylphenol.

The experiment:

Weigh the load all the components of the reaction mixture and then with stirring and while passing air heated to 90°C. The reaction time at 90°C is 6 hours. Then cooled to about 60°C and add the dissolved sodium hydroxide for neutralization used as a catalyst, sulfuric acid, and methanol for the esterification neprevyshenie anhydride methacrylic acid. Then stirred for 1 hour at 60°C and then with stirring, is added to the reaction mass 1566 g of methyl methacrylate. The resulting solution is cooled with stirring to room temperature and filtered. A solution of 4-(methacryloyloxy)benzophenone in the methyl methacrylate has the following composition, determined by gas chromatography method.

Data gas chromatographic analysis:

56,016% of methyl methacrylate,

6,954% methacrylic acid,

2,399% 4-hydroxybenzophenone,

32,717% 4-(methacryloyloxy)benzophenone.

The water content is up 0.27%, the content of the stabilizer - 113 ppm of 2,4-dimethyl-6-tert-butyl-phenol and 4 parts per million nanometrology ether of hydroquinone, chromaticity on the platinum-cobalt scale is 169.

Example 3

Equipment used: chetyrehkolka round-bottom flask with a volume of 2 l with a mechanical stirrer, reflux condenser, temperature sensor Pt100, tube to enter the air nozzle Anshutz, addition funnel, an oil bath with electric obog is evom.

Download:

a 1.5 mol of 4-hydroxybenzophenone, 303,

of 1.65 mol of anhydride methacrylic acid 96% (stabilized by the addition of 2000 ppm of 2,4-dimethyl-6-tert-butylphenol), 265 g,

0,0087 mole methanesulfonic acid, 0.84 g,

798 mg nanometrology ether of hydroquinone,

399 mg of 2,4-dimethyl-6-tert-butylphenol.

The catalyst is neutralized by addition of 0.8 g of sodium hydroxide dissolved in 5 g of water.

The excess anhydride methacrylic acid etherification the addition of 9.9 g of methanol.

The experiment:

Weigh and load all the components of the reaction mixture and then with stirring and while passing air heated to 90°C. the reaction Time at 90°C is 10.5 hours. Then cooled to about 60°C and add the dissolved sodium hydroxide for neutralization used as a catalyst, sulfuric acid, and methanol for the esterification neprevyshenie anhydride methacrylic acid. Then stirred for 1 hour at 60°C and then mixed reaction mass with 772 g of methyl methacrylate. The resulting solution was cooled to room temperature under stirring and filtered. A solution of 4-(methacryloyloxy)benzophenone in the methyl methacrylate has the following composition according to gas chromatography to the study:

49,567% of methyl methacrylate,

7,626% Methacrylonitrile,

1,635% 4-hydroxybenzophenone,

37,374% 4-(methacryloyloxy)benzophenone.

The water content is 0.36%, stabilizer 77 ppm of 2,4-dimethyl-6-tert-butylphenol and 4 parts per million nanometrology ether of hydroquinone. The color on the platinum-cobalt scale is 270.

Example 4

Equipment used: chetyrehkolka round-bottom flask with a volume of 1 l with mechanical stirrer, reflux condenser, temperature sensor Pt100, tube to enter the air nozzle Anshutz, addition funnel, an oil bath with electric heating.

Download:

of 0.75 mol of 4-hydroxybenzophenone, 149 g,

0,825 mole of anhydride methacrylic acid to 96.9% (stabilized by the addition of 2000 ppm of 2,4-dimethyl-6-tert-butylphenol), 132,4 g,

0,0174 mole monohydrate p-toluensulfonate acid, 3,3 g,

200 mg of 2,4-dimethyl-6-tert-butylphenol.

The catalyst is neutralized by addition of 0.8 g of sodium hydroxide dissolved in 2.5 g of water.

The excess anhydride methacrylic acid etherification the addition of 4.8 g of methanol.

The experiment:

Weigh all the components of the reaction mixture, added 63 g of methyl methacrylate and then under stirring and by passing air heated to 90°C. the reaction Time at 90°C is 13.5 hours. Then cooled to about 60°C and add dissolved hydro is led sodium to neutralize used as a catalyst, sulfuric acid, and methanol for the esterification neprevyshenie anhydride methacrylic acid. Then stirred for 1 hour at 60°C and then mixed reaction mass with 323 g of methyl methacrylate. The resulting solution was cooled to room temperature under stirring and filtered. A solution of 4-(methacryloyloxy)benzophenone in the methyl methacrylate has the following composition according to gas chromatography to the study:

50,323% of methyl methacrylate,

7,586% methacrylic acid,

1,058% 4-hydroxybenzophenone,

37,235% 4-(methacryloyloxy)benzophenone.

The water content is 0.64%, stabilizer 146 ppm 2,4-di-methyl-6-tert-butylphenol. The color on the platinum-cobalt scale is 500.

1. The method of obtaining the benzophenone(meth)acrylate, wherein spend interaction hydroxybenzophenones anhydride and (meth)acrylic acid in the presence of catalytic amounts of concentrated sulfuric acid, alkyl - or arylsulfonate, followed by neutralization of the catalyst and the subsequent purification of the crude monomer.

2. The method according to p. 1, characterized in that conduct the interaction of 4-hydroxybenzophenone anhydride and methacrylic acid in the presence of catalytic amounts of acid, which is then neutralized water grounds and after that soluble impurities in the melt benzie is he(meth)acrylate is dissolved by adding water.

3. The method according to p. 1, wherein the neutralization is carried out with an aqueous solution of alkali metal hydroxide or ammonia solution.

4. The method according to p. 1, characterized in that the interaction occurs in a period of time from 4 to 8 hours at a temperature of from 50 to 120°C.

5. The method according to p. 1, wherein the benzophenone(meth)acrylate precipitated by adding to the reaction mass of excess water and isolated in solid form by filtration.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: claimed invention relates to method of purifying (meth)acrylates, methacrylic acid anhydrides or acrylic acid anhydrides as monomers, in which, at least, part of monomers, contained in the initial composition, is evaporated and then condensed. At least, part of the initial composition is evaporated in short-path evaporator, with density of mass flow of flash steam m˙ being selected in accordance with ratio (I), in which M˜ stands for average molecular weight of flash steam in short-passage evaporator, kg/kmol; T stands for temperature of evaporations, K; pi stands for pressure in short-path evaporator, mbar; m˙ stands for density of mass flow of evaporations, kg/m2·h); components with low boiling point are discharged before said evaporation and condensation of present in the initial composition monomers from it by evaporation in short-path evaporator.

EFFECT: method makes it possible to purify, in particular, high-boiling monomers in simple and reliable way

m˙1800kgKmbarm2hkgkmolpi(M˜T)0,5.(1)

13 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: claimed invention relates to a method of obtaining a (meth)akrylate monomer. Described is the method of obtaining the (meth)akrylate monomer of the general formula (I): in which R1 stands for hydrogen or a methyl group, X stands for oxygen, R2 stands for a residue of an alkyl group with 3-6 carbon atoms and one aldehyde group, characterised by the fact that an initial product of formula (III): in which R1 stands for hydrogen or a methyl group, X stands for oxygen and R5 stands for an unsaturated alkyl residue with, at least, one double bond and 3-6 carbon atoms, is subjected to interaction with a carbon monoxide and hydrogen in the presence of a catalyst, which represents a complex, containing rhodium, iridium, palladium and/or cobalt and a phosphorus-containing compound as a ligand, with a ratio of a metal to the ligand preferably constituting from 1:1 to 1:1000, especially preferably from 1:2 to 1:200.

EFFECT: obtaining the (meth)akrylate monomer by the method, characterised by the higher efficiency, high selectivity, inconsiderable content of byproducts.

8 cl, 1 tbl, 24 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of methyl methacrylate (MMA) purification, which includes realisation of contact of a liquid MMA, containing admixtures, with a sulphonic acid resin in the presence of formaldehyde or an acceptable source of methylene or ethylene of formula I, as is determined below, where R5 and R6 are independently selected from C1-C12 hydrocarbons or H; X represents O; n is an integer number from 1 to 100; and m has a value of 1 or 2, and in which the sulphonic acid resin is optionally, at least, partially, deactivated.

EFFECT: method makes it possible to remove admixtures of an aldehyde type, dienes, trienes with high efficiency.

18 cl, 20 tbl, 1 dwg, 8 ex

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of obtaining ethers of (met)acrylic acid, including re-etherification of low-boiling ether of (met)acrylic acid, boiling temperature of which is lower than boiling temperature of ester, formed as a results of re-etherification, with initial alcohol in presence of main ion-exchanging substance as catalyst, and inhibitor of polymerisation, with re-etherification being carried out at temperature within the range from 50°C to 140°C. Obtained product contains insignificant amounts of byproducts and catalyst residues.

EFFECT: method is realised without labour-consuming separation of catalyst.

20 cl, 8 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing an acrylic ester of formula CH2=CH-COO-R, in which R denotes an alky radical, straight or branched, containing 1-18 carbon atoms and optionally a nitrogen heteratom, wherein at the first step glycerine CH2OH-CHOH-CH2OH is dehydrated in the presence of an acid catalyst to obtain acrolein of formula CH2=CH-CHO, then a second step where the obtained acrolein is converted via catalytic oxidation to acrylic acid CH2=CH-COOH, a third step where the acid obtained at the second step is either esterified with an alcohol R0OH, wherein R0 is CH3, C2H5, C3H7 or C4H9, followed by re-esterification of the obtained ester with an alcohol ROH, wherein R assumes the value given above, or esterified with an alcohol ROH, wherein R assumes said value, where content of furfural in the acrylic ester is less than 3 ppm.

EFFECT: high efficiency of the method.

15 cl, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to method of reverse splitting of Michael adducts, contained in fluid F with weight part ≥ 10 wt %, counted per liquid F weight, which were formed in the process of obtaining acrylic acid or its esters, in installation of reverse splitting, which includes, at least, one pump P, separation column C, which from bottom to top consists of bottom part, separating part, which is adjacent to bottom part and contains internal devices with separating effect, and head part, which follows it, in which pressure in gaseous phase decreases from bottom to top, as well as indirect heat exchanger with circulation of heat carrier UW, which has, at least, one secondary volume and, at least, one primary volume, separated from said, at least, one secondary volume by means of real separating wall D, in which fluid F with supply temperature TZ is continuously introduced into separation column C in point of supply I, which is located in said separation column C above the lowest internal device with separating effect; expenditure flow M˙ of fluid F with temperature TSU, flowing into bottom part through internal devices with separating effect, containing Michael adducts, is continuously taken away in located at the lowest level of bottom part of column C by means of pump P, in such a way that in bottom part as bottom fluid set is level S of fluid, flowing into it, which constitutes less than half of distance A, measured from point of separating column C, located at the lowest level, to lower surface of the lowest internal device with separating effect in separation column C, while in the remaining volume of bottom part, located above said level of fluid, pressure of gas GD exists, as well as, at least, one partial flow I from expenditure flow M˙* is passed through, at least, one secondary volume of indirect heat exchanger with circulation of heat carrier UW, and by indirect heat exchange with liquid heat carrier, passed simultaneously through, at least, one primary volume of said indirect heat exchanger with circulation of heat carrier UW, is heated to temperature of reverse splitting TRS, which is above temperature TSU; and from removed from, at least, one secondary volume of indirect heat exchanger with circulation of heat carrier UW with temperature TRS flow of substance M˙ in point of supply II, which is below the lowest internal element with separating effect of separation column C and above level S of bottom fluid, at least, one partial flow II is supplied back into bottom part of separation column C in such a way that said, at least, one partial flow II in bottom part of separation column C is not directed on bottom fluid, and, at least, from one of two flows M˙, M˙* discharged is partial flow as residual flow on condition that temperature of reverse splitting TRS is set in such a way that, on one hand, in the process of passage of, at least, one secondary volume of indirect heat exchanger with circulation of heat carrier UW, at least, part of Michael adducts, contained in, at least, one partial flow I, are split with formation of respective to them products of reverse splitting, as well as, on the other hand, at least, one partial flow II, supplied back into separation column C, under existing in bottom part in point of supply II gas pressure GD, is boiling, and gaseous phase, which is formed in the process of boiling, containing, at least, partial amount of product of reverse splitting, is supplied into head part of column C as gas flow G, containing product of reverse splitting, following decreasing towards head part of column C gas pressure, and said gas flow G by direct and/or indirect cooling is partially condensed still in head part of separation column C and/or being discharged from head part of separation column C, condensate, formed in this process is, at least, partially returned to separation column C as reflux fluid, and gas flow, remaining in the process of partial condensation, is discharged, with pump P representing radial centrifugal pump with semi-open radial working wheel. Coefficient of efficiency Q of claimed method constitutes at least 20%.

EFFECT: improvement of method.

14 cl, 9 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing higher alkyl(meth)acrylates which are used in synthesis of polymer depressor additives intended to prevent setting and reduction of low-temperature viscosity of paraffin-base oil. The method involves esterification of acrylic acid or a mixture of acrylic acid and methacrylic acid with higher fatty alcohols C16-C26 in a medium of a hydrocarbon solvent in the presence of an acid catalyst and a radical polymerisation inhibitor, followed by neutralisation of the acidic reaction mass using higher primary amines C8-C14 at temperature of 20-90°C and molar ratio of amine groups to free acid groups of (1.0-1.3):1.0. After said neutralisation, the solution of higher alkyl(meth)acrylates can be used to produce polymer depressor additives without further purification.

EFFECT: avoiding formation of wastes in form of salts of salt-containing waste water, high output of products owing to reduced loss of monomers at the neutralisation step, and simple technique of producing the monomer mixture for synthesis of depressor additives for paraffin-base oil.

2 tbl, 23 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing ethylenically unsaturated acids and esters thereof of the following formula: R3-C(=(CH2)m)-COOR4 , where R3 and R4 each independently represent hydrogen or an alkyl group, and m equals 1, by reacting alkanoic acid or an alkanoic acid ester of formula R3-CH2-COOR4, where R3 and R4 each independently represent hydrogen or an alkyl group with a methylene or ethylene source of formula , where R5 and R6 are independently selected from C1-C12 hydrocarbon groups or H; X is O or S; n is an integer from 1 to 100; and m equals 1, in the presence of a catalyst system to an ethylenically unsaturated acid or ester as a product, where the product in form of an acid or ester is then brought into contact with a dienophile to eliminate the undesirable colour of the product, where the dienophile is a compound of formula: where Z is selected from a group consisting of -C(O)Y, -CN, -NO2 or halogen; Y is selected from a group consisting of hydrogen, alkyl, hetero, -OR, halogen or aryl; R, R1 and R2 independently denote hydrogen, alkyl or aryl, and hetero denotes N, S or O. The heteroatoms can be unsubstituted or substituted with one or more groups consisting of hydrogen, alkyl, -OR, aryl, aralkyl or alkaryl, where R is as defined for Y; Z' can denote any group selected above for Z, or can also denote hydrogen, alkyl, aryl or hetero; or Z and Z1 together can form a -C(O)Y(O)C- group so that the dienophile forms a cyclic group of formula , where R1 and R2 are as defined above, Y is hetero as defined above, or Y is an alkylene group of formula -(CH2)s-, where s equals 1, 2 or 3.

EFFECT: obtained products comes into contact with a dienophile to eliminate the undesirable colour of the product.

37 cl, 2 dwg, 10 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of obtaining aminoacrylates (dimethylaminoethylacrylate and dimethylaminoethylmethacrylate) by transesterification of methylacrylate or methylmethacrylate by dimethylethanolamine at increased temperature in presence of Ti-containing liquid-phase catalyst. Synthesis is realised in two successive reactors: first, which works without methanol distillation, to conversion of DMAE 30-40% and second, from which distillation of methanol is carried out continuously to complete conversion of initial DMAE, with recycle of unreacted acrylate into first reactor and recycle of DMAE into second reactor.

EFFECT: method makes it possible to simplify reactor unit, increase specific productivity with preservation of high selectivity of process.

1 dwg, 2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing acetone cyanohydrin. The disclosed method comprises the following steps: A) reacting acetone and hydrogen cyanide in a reactor to obtain a reaction mixture, wherein the reaction mixture is subjected to circulation and acetone cyanohydrin is obtained; B) cooling at least a portion of the reaction mixture; C) removing at least a portion of the obtained acetone cyanohydrin from the reactor; D) continuous distillation of the removed acetone cyanohydrin to obtain a bottom product of acetone cyanohydrin and an overhead product of acetone in a distillation column; E) returning at least a portion of the overhead product of acetone to step A, wherein during returning, the overhead product of acetone is kept at temperature lower than 60°C, and the reaction to produce acetone cyanohydrin is carried out in the presence of a base catalyst. The invention also relates to methods of producing an alkyl ester of methacrylic acid and methacrylic acid which, as one of the steps, include producing acetone cyanohydrin using the disclosed method, a method of producing polymers based at least in part on alkyl esters of methacrylic acid, an apparatus for producing alkyl esters of methacrylic acid and use thereof.

EFFECT: method enables to prevent splitting of the overhead product of acetone and, as a result, reduces formation of deposits in the system when producing acetone cyanohydrin.

19 cl, 7 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing ethylenically unsaturated acids and esters thereof of the following formula: R3-C(=(CH2)m)-COOR4 , where R3 and R4 each independently represent hydrogen or an alkyl group, and m equals 1, by reacting alkanoic acid or an alkanoic acid ester of formula R3-CH2-COOR4, where R3 and R4 each independently represent hydrogen or an alkyl group with a methylene or ethylene source of formula , where R5 and R6 are independently selected from C1-C12 hydrocarbon groups or H; X is O or S; n is an integer from 1 to 100; and m equals 1, in the presence of a catalyst system to an ethylenically unsaturated acid or ester as a product, where the product in form of an acid or ester is then brought into contact with a dienophile to eliminate the undesirable colour of the product, where the dienophile is a compound of formula: where Z is selected from a group consisting of -C(O)Y, -CN, -NO2 or halogen; Y is selected from a group consisting of hydrogen, alkyl, hetero, -OR, halogen or aryl; R, R1 and R2 independently denote hydrogen, alkyl or aryl, and hetero denotes N, S or O. The heteroatoms can be unsubstituted or substituted with one or more groups consisting of hydrogen, alkyl, -OR, aryl, aralkyl or alkaryl, where R is as defined for Y; Z' can denote any group selected above for Z, or can also denote hydrogen, alkyl, aryl or hetero; or Z and Z1 together can form a -C(O)Y(O)C- group so that the dienophile forms a cyclic group of formula , where R1 and R2 are as defined above, Y is hetero as defined above, or Y is an alkylene group of formula -(CH2)s-, where s equals 1, 2 or 3.

EFFECT: obtained products comes into contact with a dienophile to eliminate the undesirable colour of the product.

37 cl, 2 dwg, 10 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing butanediol dimethacrylates, involving transesterification of an ester of methacrylic acid with butanediol, formed by an alcohol, containing 1-4 carbon atoms, in the presence of a catalyst, where the catalyst used is a combination which contains at least one lithium compound and at least one calcium compound, wherein at least one of the lithium and/or calcium compounds is an oxide, hydroxide, alkoxide containing 1-4 carbon atoms, or a carboxylate containing 1-4 carbon atoms, and the reaction takes place in the presence of water in amount of 0.005-8 wt % with respect to the weight of the butanediol used at the beginning of the reaction, with optional ageing of said amount of water for the entire transesterification process.

EFFECT: method enables to obtain butanediol methacrylates at a very low cost and having very high purity.

35 cl, 6 ex

FIELD: chemistry.

SUBSTANCE: apparatus for re-esterification of organic acid with ester has a fixed-bed catalytic reactor and a distillation column, where the pipe between the reactor and the distillation column is fitted with pressure increasing apparatus, and the head of the distillation column is connected to a phase separator which is in turn connected to said reactor, and flow to the reactor passes through a heat exchanger for regulating reaction temperature. The re-esterification method involves the following steps: A) mixing organic acid a) with ester b) and B) transfer of the alcohol residue of the ester b) to the acid a), accompanied by formation of an ester of acid a) and an acid of ester b), where the transfer of the alcohol residue of the ester b) to the acid a) at step B) is carried out in the apparatus described in claim 1. Reactants are fed into the distillation column to carry out re-esterification in the fixed-bed catalytic reactor lying outside the column; a portion of the liquid phase flowing downwards inside the distillation column is trapped and output from the column in form of a separate stream whose pressure is raised using the pressure increasing apparatus and its temperature is controlled in the heat exchanger before being fed into the reactor; the stream coming out of the reactor is fed into the distillation column where the mixture of reaction products is separated and the stream coming out of the top of the column is separated in the phase separator.

EFFECT: reduced expenses.

11 cl, 1 dwg, 2 tbl, 38 ex

FIELD: chemistry.

SUBSTANCE: invention relates to method of (meth)acrylate storing. More specifically, claimed invention relates to method of storing alkyl ester of acryl or methacryl acid in reservoir during circulation or mixing at temperature from 15 for 50°C, which includes feed of gas mixture, obtained by mixing of incombustible inert gas with molecular oxygen, in reservoir, where: concentration of molecular oxygen in gas mixture is from 2 to 10 vol %; reservoir is produced from carbonaceous steel and equipped with pipe for gas input and pipe for gas output; gas has concentration of water 100 volume parts per million (vol. p/mln) or less; and alkyl ester of acryl or methacryl acid has concentration of (meth)acryl acid 30 weight parts per mln (wt, p/mln) or less.

EFFECT: reservoir for storing from less expensive and very universal material without losing stored (meth)acrylate stability.

2 cl, 3 ex

FIELD: organic chemistry, chemical technology, pharmacy.

SUBSTANCE: invention relates to the improved method for isolating and purifying pravastatin or its pharmacologically acceptable salt from impurities of pravastatin analogues. Method involves extraction of pravastatin or its pharmacologically acceptable salt comprising impurities of pravastatin analogues with organic solvent of the formula: CH3CO2R wherein R represents alkyl comprising 3 or 4 carbon atoms. Also, invention relates to the improved method for isolating or purifying pravastatin or its pharmacologically acceptable salt that involves decomposition of impurities by using inorganic acid or that involves removing compound of the formula (I): by using inorganic solvent. Also, invention relates to the composition comprising pravastatin sodium salt and compound of the formula (I) taken in the amount 0.1 wt.-% or less with respect to the amount of pravastatin sodium salt. Method provides preparing the end product of the high purity degree.

EFFECT: improved purifying method.

18 cl, 1 tbl, 8 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of processing ammonium lactate into lactic acid and esters thereof. The disclosed method is carried out by bringing aqueous ammonium lactate solution into contact with a hydroxyl-containing compound in a vertical mass-exchange apparatus at high temperature and pressure, removing reaction by-products, primarily with a stream of steam and end products, primarily with a liquid stream. The process is carried out in adiabatic conditions in one or more mass-exchange apparatus.

EFFECT: method simplifies the process of converting ammonium lactate and reduces power consumption, prevents salt deposits on heated surfaces, reduces the amount of alcohol fed into the reaction, while maintaining a high degree of conversion of ammonium lactate and short duration of the process.

5 cl, 4 dwg, 5 ex

FIELD: medicine, pharmaceutics.

SUBSTANCE: claimed invention relates to compounds of the following formula , in which n equals integer number from 1 to 15, m equals 0, 1, 2 or 3, and R represents hydrocarbon chain of polyunsaturated fatty acid, selected from omega-3 and omega-6 polyunsaturated fatty acids, and to method of obtaining them.

EFFECT: development of pharmaceutical or cosmetic composition based on said compounds and to method of acne or seborrheic dermatitis treatment for cosmetic purposes.

16 cl, 4 dwg, 2 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing an acrylic ester of formula CH2=CH-COO-R, in which R denotes an alky radical, straight or branched, containing 1-18 carbon atoms and optionally a nitrogen heteratom, wherein at the first step glycerine CH2OH-CHOH-CH2OH is dehydrated in the presence of an acid catalyst to obtain acrolein of formula CH2=CH-CHO, then a second step where the obtained acrolein is converted via catalytic oxidation to acrylic acid CH2=CH-COOH, a third step where the acid obtained at the second step is either esterified with an alcohol R0OH, wherein R0 is CH3, C2H5, C3H7 or C4H9, followed by re-esterification of the obtained ester with an alcohol ROH, wherein R assumes the value given above, or esterified with an alcohol ROH, wherein R assumes said value, where content of furfural in the acrylic ester is less than 3 ppm.

EFFECT: high efficiency of the method.

15 cl, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing pure methacrylic acid, which involves: a) gas-phase oxidation of a C4 compound to obtain a methacrylic acid-containing gas phase, b) condensing the methacrylic acid-containing gas phase to obtain an aqueous methacrylic acid solution, c) separating at least a portion of the methacrylic acid from the aqueous methacrylic acid solution to obtain at least one methacrylic acid-containing raw product, d) separating at least a portion of methacrylic acid from the at least one methacrylic acid-containing raw product by thermal separation to obtain pure methacrylic acid, wherein at step (d), methacrylic acid is separated from at least a portion of at least one methacrylic acid-containing raw product by fractionation, and wherein the pure methacrylic acid is collected through a side outlet used for the fractionation column, and the amount of pure methacrylic acid collected over a certain time interval ranges from 40% to 80% of the amount of the methacrylic acid-containing raw product fed into the fractionation column over the same time interval. The invention also relates to an apparatus for producing methacrylic acid using said method, the apparatus comprising: a1) a gas-phase oxidation unit, b1) an absorption unit, c1) a separation unit, and d1) a purification unit, wherein the purification unit has at least one distillation column, wherein the at least one distillation column has at least one side outlet for pure methacrylic acid. The invention also relates to a method of producing methacrylic esters, polymethacrylate, polymethacrylic esters, which includes a step for said production of pure methacrylic acid.

EFFECT: obtaining an end product with fewer by-products while simplifying the process.

32 cl, 3 tbl, 4 dwg, 6 ex

FIELD: machine building.

SUBSTANCE: invention refers to a method for obtaining an ether additive, which involves mixing of dicarboxylic acid with ether so that water, ether and excess alcohol is obtained with further separation of water and alcohol from ether by rectification; at that, as an acid there used is oxalic acid, and as alcohol - n-butanol or 2-ethylhexanol. Cyclohexane used as a solvent is supplied for mixing of oxalic acid with alcohol, and rectification is performed in two columns so that cyclohexane (solvent) is obtained in the first column, which is returned to the stage of mixing with oxalic acid and alcohol and supply of residue of the first column to the second one so that alcohol and target product (ether additive) are obtained in it.

EFFECT: method allows simplifying the process and making it more economic by excluding the use of a catalyser, processing stages of reaction mass with an agent decomposing the catalyser, and reaction mass sorption and filtration stages.

2 cl, 2 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to chemical engineering and specifically to processing fusel oil, which is a large-tonnage waste in the alcohol industry. Fusel oil from production of ethyl alcohol is processed by esterification with glacial acetic acid in the presence of a sulphuric acid catalyst, and neutralisation, wherein esterification is carried out while boiling the reaction mixture and continuously separating water using a separating flask. The obtained product is separated from the catalyst under a vacuum at temperature not higher than 110°C. The obtained product and the catalyst are separately neutralised and the obtained product is additionally dried.

EFFECT: method enables to process fusel oil into a highly efficient component of mixed solvents of high quality with low cost of production and high output of the product.

4 cl

Up!