Method of purifying ε-caprolactam

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of purifying crude ε-caprolactam obtained from cyclohexanone oxime via gas phase Beckmann rearrangement, comprising a step for crystallisation of ε-caprolactam from the solution of crude ε-caprolactam in ether or halogenated hydrocarbon, a step for washing the crystalline ε-caprolactam obtained from the crystallisation step with a solvent and a step for hydrogenation of the crystalline ε-caprolactam through contact with hydrogen in the presence of a hydrogenation catalyst.

EFFECT: high purity of the product, high absorption of potassium permanganate and extraction coefficient at wavelength 290 nm equal to or less than 0,05, which meets all requirements for commercial products.

19 cl, 12 ex

 

The technical field to which the invention relates.

The present invention relates to a method for producing ε-caprolactam, and more particularly to a method of purification of ε-caprolactam.

Prior art

ε-Caprolactam is one of the important raw materials for synthetic fibers and synthetic resins, especially for polyamide fibers (nylon 6), resins, films, etc. In the present method for industrial preparation of caprolactam mainly includes a Beckmann rearrangement in cyclohexanehexol in the liquid phase in the presence of fuming sulfuric acid as catalyst and solvent. However, this process has drawbacks such as corrosion of the equipment, environmental pollution and poor economic performance, and a large amount of ammonium sulfate produced as a by-product.

Beckmann rearrangement cyclohexasiloxane in the gas phase using a solid acid catalyst is a new process for production of ε-caprolactam without ammonium sulfide. This process eliminates the disadvantages such as corrosion of the equipment, environmental pollution, etc. and the resulting product can be purified by a simple way. Therefore, in the technique have shown great interest in this new process Beckmann rearrangement in the gas is howling phase without ammonium sulfide.

Domestic and foreign scholars have done a lot of work for two main types of catalysts, i.e. the oxide (or oxide complexes) and molecular sieves, for the development of solid acid catalyst suitable for the Beckmann rearrangement in the gas phase to obtain ε-caprolactam.

However, ε-caprolactam obtained by these methods contains various impurities. It is well known that the ε-caprolactam is used as raw material for production of the polyamide, and ε-caprolactam, which is used to obtain polyamide, which in turn is used to obtain synthetic fibres or of synthetic resins, must be of high purity. Impurities, even in the order of µg/g will result in negative effects in the subsequent polymerization of ε-caprolactam, with further difficulties in the formation of the thread. Thus, the crude ε-caprolactam first cleaned in different ways, different then the final processes get ε-caprolactam of high purity that it can be used for the manufacture of products such as synthetic fibers, synthetic resin and films etc.

The selection of ε-caprolactam obtained by the Beckmann rearrangement in liquid phase, involves the neutralization of the reaction product of the rearrangement, the extraction of ammonium sulfide, leaching, extraction benzo is om, the water extraction, ion exchange, hydrogenation, evaporation in trehkorpusny apparatus and distillation, etc. So many operations for separation and purification of the reaction product is partially caused by the presence of inorganic ammonium sulfide.

Purification methods such as extraction, distillation and ion exchange admixture with chemical properties similar to ε-caprolactam, or by-products with boiling points close to the boiling point of ε-caprolactam, cannot be removed completely, and the hydrogenation can be effective in this case because, on the one hand, caprolactam or the structural isomers can be converted into ε-caprolactam by hydrogenation; and, on the other hand, the absorption of permanganate potassium product can be effectively increased by hydrogenation. However, the conditions for the hydrogenation are so hard that the efficiency of reaction and absorption of permanganate potassium with the reaction product would be reduced if the hydrogenation would be held too deeply.

As mentioned above, ε-caprolactam with the purity required for the industry, there can be stably obtained from a conventional purification methods such as distillation, rectification, extraction, ion exchange, adsorption and hydrogenation, etc. individually or in combination.

The way to obtain ε-caprolactam, disclosed in CN 126301 And, includes crystallization of ε-caprolactam from a solution of a hydrocarbon containing crude ε-caprolactam, and the contacting crystalline ε-caprolactam with hydrogen in the presence of a hydrogenation catalyst, to obtain ε-caprolactam of high purity. When using this method, impurities can be effectively removed from the crude ε-caprolactam obtained by rearrangement Baksana cyclohexasiloxane to obtain ε-caprolactam of high purity.

Disclosure of inventions

The aim of the present invention is to provide a new method of purification of ε-caprolactam based on the known prior art, the effective removal of impurities and by-products from the crude ε-caprolactam to obtain ε-caprolactam of high purity.

The method of purification of ε-caprolactam in accordance with the present invention includes a step of crystallization of ε-caprolactam from a solution of an ether or halogenated hydrocarbon containing crude ε-caprolactam. More precisely, this method involves distillation of a liquid mixture of solvent and ε-caprolactam obtained by the reaction of synthesis of the crude ε-caprolactam, mixing the crude ε-caprolactam in the molten state with ether or halogenated hydrocarbon solvent and crystallization of the resulting solution, followed by rinsing with a solvent obtained Chris is alicebraga ε-caprolactam, as well as contacting ε-caprolactam with hydrogen in the presence of a hydrogenation catalyst, to obtain ε-caprolactam in the form of a final product, wherein said ether or halogenated hydrocarbons have a boiling point in the range of 30-150°C., preferably 50-120°C., more preferably 60-100°C, and are used in quantities of from 0.3 to 3, preferably from 0.6 to 1.5, more preferably from 0.8 to 1.2 weight parts per weight part of the ε-caprolactam.

The method in accordance with the present invention is suitable for the purification of ε-caprolactam obtained in various ways. Specified crude ε-caprolactam is usually obtained by Beckmann rearrangement cyclohexasiloxane in liquid or gas phase, as well as other methods of synthesis. When the specified crude ε-caprolactam obtained by the Beckmann rearrangement cyclohexasiloxane in the gas phase in the presence of the oxide catalyst or molecular sieves as catalyst, this method has a significant advantage, i.e. impurities, for example, cyclohexanone, Octo hydrogenation, capreolata, tetrabenzoate etc. can be removed from the crude ε-caprolactam completely, especially after the stage of crystallization and hydrogenation of the obtained ε-caprolactam may contain less than 10 μg/g cyclohexasiloxane, less than 10 μg/g 1,2,3,4,6,7,8,9-Octo guide is uphenazine and less than 30 μg/g capreolata, as well as its structural isomers.

In accordance with this method the crude ε-caprolactam obtained by distillation, typically includes at least 50 mcg/g cyclohexasiloxane, at least 30 μg/g 1,2,3,4,6,7,8,9-Octo hydrogenation and at least 50 mcg/g of capreolata and its structural isomers. In addition to the above impurities crude ε-caprolactam can sometimes contain a solvent, with the specified solvent is usually an alcohol, such as lower alcohols, for example methanol and/or ethanol, or other solvents.

In accordance with this method, the ether used at the stage of crystallization selected from the group consisting of normal simple ether, simple branched ether, simple diapir, a partial ester of a polyhydric alcohol and ethers of olefins, examples may include ethyl ether, n-propyl ether, isopropyl ether, n-butyl ether, methylbutylamine ether, ethylbutylamine ether, dimethyl ether glycol vinyl ether, methyl tertiary butyl ether, ethylcelluloses ether and mixtures thereof.

In accordance with this method halogenated hydrocarbon phase crystallization selected from the group consisting of normal halogenated hydrocarbon, branched halogenated hydrocarbon, dehalogenating hydrocarbon and TRIG is generowania hydrocarbon, examples may include n-chloropropane, isolobodon, n-chlorobutane, 2-chlorobutane, isobarbaloin, tertbutyl chloride, n-bromopropane, isopropropyl, 1-rambutan, 2 rambutan and mixtures thereof.

In accordance with the present method further phase crystallization enter the seed. Although the crystallization can be performed once or several times, it has been found that good results can be achieved if the phase crystallization only once.

The specified stage of crystallization can be performed fractionated crystallization, i.e. conducting multiple stage crystallization based on the countercurrent principle. Thus, after each stage of the crystallization product of crystallization is separated from the liquid (mother liquor) and pass on the appropriate stage with lower purity, and the remainder is passed at a suitable stage with higher purity.

The temperature of the solution or melt during crystallization is not higher than the melting point of the ε-caprolactam (i.e. 70°C.) and preferably is in the range from -10°C up to the melting point of ε-caprolactam, especially in the range from 20°C to the melting point of the ε-caprolactam.

In the case of crystallization upon cooling, heat is removed using a scraper capacitor attached to the vessel with stirring and the tank is ez mixing. The suspension of crystals you can move the pump. Another possible way to remove heat is to use wall of the tank with agitator for removing heat. Another preferred implementation of the crystallization by cooling is the use of a flat-cooled mold. In another suitable implementation of crystallization by cooling, the heat may be removed by conventional heat exchanger and preferably shell-and-tube heat exchanger or plate heat exchanger. Compared with the scraper condenser tank with agitator or flat-cooled mold has no means to prevent the formation of layers of crystals on surfaces. In the usual implementation, if there is excess thermal resistance due to the formation of layers of crystals during the execution of the method, it can be implemented in the second device and the method can be carried out continuously. The first device may be regenerated during operation of the second, and the method can be performed in the first device when excessive thermal resistance occurs in the second device, and so forth. An alternative is the implementation can be done in more than two devices.

Department of crystalline caprolactam from the mother liquor is well known to specialists in this field the minute technology.

The crystals can be separated from the mother liquor by filtration and/or centrifugation. A preferred centrifuge running on axial pressure, which can operate in single or multi-stage mode. You can also use / tube sheet centrifuge or centrifuge spiral unloading (the decanter). Filtering can be accomplished by using sieves, which are periodically or continuously, with or without stirring, or a band filter. The filtering is usually used at greater than atmospheric pressure or under reduced pressure.

In accordance with this method other stages of the method can be applied during and/or after separation of the solid phase and liquid, to improve the purity of the crystals or precipitate on the filter. For example, after separation of the crystals and the mother liquor can be entered stage washing with a solvent for washing the crystals or precipitate on the filter one or more times.

The specified stage of the washing solvent can be held in common for this purpose devices, such as washing column, the separation of the mother liquor and the washing of the crystals can be held in the same device as the separation, such as a centrifuge or belt filter. Washing of the crystals can be carried out in a centrifuge or belt filter in one or several stages, and wash Astor can be routed to precipitate on the filter with backflow.

This washing can be carried out once, or repeatedly, or continuously. In accordance with the present invention there are no special requirements for the selection of solvents for washing, which can be ethers, halogenated hydrocarbons, normal waxes and cycloparaffins with a boiling point below 150°C, for example, isopropyl ether, methyl tertiary butyl ether, ethyl ether, n-chlorobutane, n-heptane, cyclohexane, etc. In accordance with the present method specified solvents for washing are preferably the same as the solvent for crystallization, i.e. the specified solvent for washing is preferably the same simple ether or halogenated hydrocarbon as the solvent for crystallization.

In accordance with the present method specified by the catalytic hydrogenation is preferably amorphous Nickel. The specified catalyst mentioned in Chinese patents ZL99106165.9, ZL99106167.5, ZL00109588.9 and CN1552698A, which are included in the description by reference. Specified amorphous catalyst is usually used for the purification of the product of the Beckmann rearrangement in the liquid phase, however, the authors of the present invention have found that a positive effect can also be achieved with this catalyst in the hydrogenation product paragraphi ovci Beckmann in the gas phase. During hydrogenation specified ε-caprolactam can be contacted with hydrogen in the molten state, an aqueous or organic solution. This reactor used for the hydrogenation may be a slurry reactor, a reactor with a fixed bed or reactor magnetically stabilized layer. Reaction conditions specified hydrogenation include a temperature in the range from 80 to 150°C. and a pressure in the range from 2 to 15 ATM.

In accordance with this method stage of selection by distillation in trehkorpusny apparatus or vacuum distillation, etc. can be performed after the hydrogenation, to obtain ε-caprolactam. Obtained by this way the product can have a purity of 99.98% or more, the absorption of potassium permanganate 10,000 or more and an extinction coefficient of ε-caprolactam at a wavelength of 290 nm, equal to 0.05 or less, so as to satisfy all the requirements of industrial products.

The implementation of the invention

Further, the present invention is illustrated in the following examples, which in no way intended to limit the scope of the claims of the present invention.

In the following examples, the obtained ε-caprolactam define the following test methods:

(1) the Purity of ε-caprolactam and the content of impurities

Net is the ε-caprolactam and the content of impurities in the final ε-caprolactam was investigated by gas chromatography and calculated by manual integration. The limit of detection of impurities is 2 mcg/g

(2) the Absorption of potassium permanganate (RM) ε-caprolactam.

3,000 grams of ε-caprolactam weighed into 100 ml colorimetric cylinder and diluted with distilled water to the indicated volume. The cylinder uniformly shaken and then placed in a water bath at a constant temperature of 20.0°C. 1 ml of 0.01 N aqueous solution of potassium permanganate is added in colorimetric cylinder and immediately shake evenly. At the same time include a stopwatch to record the time. When the color of the sample solution in the colorimetric cylinder is the same as the standard colorimetric solution, which is obtained by dissolution of 3,000 grams of Co(NO3)2·6N2O qualifications "clean" and 12 milligrams of K2Cr2O7the qualification of "pure" water, diluting the solution to 1 liter with uniform mixing, the stopwatch is stopped. Reading of the stopwatch in seconds is the absorption of potassium permanganate.

(3) the extinction Coefficient E (at a wavelength of 290 nm)

In a 300 ml conical flask weighed 50 grams of sample, add 50 ml of distilled water and the sample is dissolved completely in uniform shaking, and then the flask was left for 10 minutes. The light source of the spectrophotometer switch to the deuterium lamp and turn the meter on. D. the inu waves set at 290 nm, click "design" and then click "%T". 1 cm optical quartz cuvette with distilled water is placed in the holder sample compartment in the path of the light beam, the sample compartment cover, open the shutter in the beam path of the light pulling rod and adjust the gap to the value of T was greater than 50%, then click "100%", now the tool shows "KZT100", then press the button "A". Distilled water is replaced by the sample, conduct the operations described above, and the device shows the extinction coefficient.

EXAMPLES

Example 1

Obtaining the crude ε-caprolactam

The Beckmann rearrangement cyclohexasiloxane in the gas phase is carried out in a reactor with a fixed 80 ml layer with an inner diameter of 28 mm was charged To the reactor of 9.45 g of molecular sieves as catalyst with the MFI structure with a high ratio of silicon to aluminum (the catalyst in the form of strips F1,8 mm). The pressure during the reaction is 0.1 MPa, and the reaction temperature in the catalyst bed is from 365 to 385°C. the flow Rate of the carrier gas is 3.0 l/gcat/h, and WHSV cyclohexanehexol is 2 h-1. The partial pressure in the mixed stream is 5.5-11.6 kPa cyclohexasiloxane, 36,9-70,6 kPa methanol (solvent), and 19.4-52,6 kPa nitrogen (carrier gas), respectively. The exhaust gas of the reaction is collected by cooling the CID is ulacia of ethylene glycol at -5°C, to obtain a reaction product containing ε-caprolactam.

The reaction mixture is distilled by simple distillation to remove methanol, impurities with lower boiling points and impurities with higher boiling points to obtain the crude ε-caprolactam. Crude ε-caprolactam analyze gas chromatograph model 6890 available in Agilent Company, with an ionization detector in a hydrogen flame and PEG20M capillary chromatographic column length 50 m After the analysis of the composition of the crude ε-caprolactam was the following: 99,2% ε-caprolactam, 1225 mg/g cyclohexasiloxane, 686 µg/g octahydrophenanthrene and 598 ág/g capreolata.

Stage crystallization

A 10 l reactor was placed 2.0 kg crude ε-caprolactam obtained above simple distillation, then add 2.0 kg of isopropyl ether. The mixture is heated to a temperature of 60-70°C and stirred for 30 minutes for complete dissolution of ε-caprolactam in the specified solvent. Stirring, reduce the temperature from 70°C to about 15°, so that the crystalline ε-caprolactam was precipitated completely. After separation by centrifugation get 1,94 kg 99,92% crystalline ε-caprolactam and 2,05 kg 95,8% of isopropyl ether. The ether used as solvent, return to loop.

Stage wash

1,94 kg Krista is symbolic ε-caprolactam placed in a 10 l reactor, add in the reactor 1,94 kg of isopropyl ether and the crystals washed with stirring at room temperature for 30 minutes. After separation by centrifugation get 99.96% of crystalline ε-caprolactam and 98.6% of isopropyl ether (containing, in addition, 1,20% ε-caprolactam). Isopropyl ether extract. As a result of analysis of the obtained ε-caprolactam is the time of absorption of RM 100 and the value of E is less than 0.5.

Stage hydrogenation

In a 10 l reaction container is placed 1,90 kg of 99.96% crystalline ε-caprolactam, which was washed once with isopropyl ether, then add of 4.44 kg of water and 190 g of amorphous catalyst for hydrogenation (commercial trademark of SRNA-4 and commercially available in the petrochemical Corporation JianChang in Hunan, China). The reaction mixture is heated to approximately 100°C, the hydrogen purge with a controlled flow rate of 0.6 l/min and the pressure during the reaction is 7 MPa, so that the aqueous solution crystallized ε-caprolactam was in contact with hydrogen, reacting for one hour. After evaporation in trehkorpusny apparatus and vacuum distillation at about 1 mm Hg receive 1,88 kg of ε-caprolactam. The yield is 99%. After analysis, the final ε-caprolactam is the absorbance value of the RM, is equal 41000 C and E less than 0.02.

Example 2

P is Vtoraya stage for receiving crude ε-caprolactam example 1.

Stage crystallization of example 1 is repeated, except that the amount of isopropyl ether, used for crystallization, is 1.0 kg, so get 1,95 kg 99,90% crystalline ε-caprolactam and 1.03 kg 95.5% of isopropyl ether.

Repeat stage leaching of example 1, except that the amount of isopropyl ether, used for washing, is 2.0 kg, so get 99.95% of crystalline ε-caprolactam and 98.5% of isopropyl ether (containing, in addition, 1,26% ε-caprolactam). The obtained ε-caprolactam is the absorbance value of the RM 80 and the value of E is less than 0.6.

Stage hydrogenation

Crystalline ε-caprolactam obtained in the previous stage, make a 5 l reactor and then added to the reactor 190 g SRNA-4 commercial amorphous Nickel hydrogenation catalyst. The reaction mixture is heated to approximately 90°C, the hydrogen purge with a controlled flow rate of 0.6 l/min and the pressure during the reaction is 5 ATM, so that ε-caprolactam in the molten state in contact with the hydrogen, reacting for one hour. Subsequently, the reaction product is distilled in a vacuum at approximately 1 mm Hg, thus obtaining 1.86 kg of ε-caprolactam. The output is 98%. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 3200, and the value of E is less than 0.02.

Example 3

Repeat step for crude ε-caprolactam example 1.

Stage crystallization of example 1 is repeated, except that the amount of isopropyl ether, used for crystallization, is 2.8 kg, so get 1,91 kg 99,94% crystalline ε-caprolactam and 2.86 kg 95.9% of isopropyl ether.

Repeat stage leaching of example 1, except that the amount of isopropyl ether, used for washing, is 2.0 kg, thus achieving 99.97% of the crystalline ε-caprolactam and 98,7% isopropyl ether (containing, in addition, 1,18% ε-caprolactam). The obtained ε-caprolactam is the absorbance value of the RM 120 and the value of E is less than 0.5.

Stage hydrogenation

SRNA-4 commercial amorphous Nickel is used as catalyst in the reactor with a magnetic stabilized layer. The reaction mixture is heated to approximately 90°C, the hydrogen purge with a controlled flow rate of 0.6 l/min and the pressure during the reaction is 5 ATM, so that ε-caprolactam in the molten state in contact with the hydrogen, reacting for one hour. Subsequently, the reaction product is distilled in a vacuum at approximately 1 mm Hg. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 36,000, and the value of E is less than what is 0.04.

Example 4

Repeat step for crude ε-caprolactam example 1.

Stage crystallization of example 1 is repeated, except that used for crystallization dimethyl ether glycol as a solvent in the amount of 5.0 kg Thus obtained 1.8 kg 99,94% crystalline ε-caprolactam and 5,14 kg 97.1% of dimethyl ether glycol.

Repeat stage washing of example 1, except that the use of dimethyl ether glycol as a solvent for washing in the amount of 2.0 kg of the Thus obtained 99.96% of crystalline ε-caprolactam and a 99.0% dimethyl ether glycol (containing, in addition, 0.8% of ε-caprolactam). The obtained ε-caprolactam is the absorbance value of the RM 90 and the value of E is less than 0.6.

Stage hydrogenation

Commercial amorphous Nickel SRNA-4 is used as catalyst in the reactor with a magnetic stabilized layer. The reaction mixture is heated to approximately 90°C, the hydrogen purge with a controlled flow rate of 0.6 l/min and the pressure during the reaction is 5 ATM, so that ε-caprolactam in the molten state in contact with the hydrogen, reacting for one hour. Subsequently, the reaction product is distilled in a vacuum at approximately 1 mm Hg. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 40000, and C is Uchenie E less than 0.03.

Example 5

Repeat example 1, except that the use of ethyl ether instead of isopropanol as a solvent for crystallization and washing. The obtained ε-caprolactam is the absorbance value of the RM, is equal to 80 and the value of E is less than 0,65 after washing. After hydrogenation perform evaporation in trehkorpusny the device, followed by vacuum distillation at about 1 mm Hg. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 22000, and the value of E is less than 0.05.

Example 6

Repeat example 1, except that the use of methyl tertiary butyl ether instead of isopropanol as a solvent for crystallization and washing. The output obtained ε-caprolactam after crystallization is 93,34% and a purity of 99.96% and the obtained ε-caprolactam is the absorbance value of the RM, is equal to 160 C and the value of E is less than 0.33 after washing. Then carry out the hydrogenation, the evaporation in trehkorpusny apparatus and vacuum distillation. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 30000, and the value of E is less than 0.05.

Example 7

Repeat example 1, except that the use of methyl tertiary butyl ether instead of isopropanol as a solvent for crystallization and washing and stage leaching perform twice. The output ε-caprolactam is 93,34% and pureness is of 99.96% after crystallization; and the output of ε-caprolactam after the second stage is 97.5% and the purity of 99.98%. Then carry out the hydrogenation, the evaporation in trehkorpusny apparatus and vacuum distillation. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 33000 from, and the value of E is less than 0.04.

EXAMPLE 8

Repeat step for crude ε-caprolactam example 1.

Repeat stage crystallization of example 1.

Stage leaching of example 1 is repeated except that the use of n-heptane instead of isopropyl ether as the solvent for washing. So get 99.95% of crystalline ε-caprolactam and 98,8% n-heptane (containing, in addition, 1,00% ε-caprolactam). The obtained ε-caprolactam is the absorbance value of the RM, is equal to 126, and the value of E is less than 0.6.

Repeat stage hydrogenation of example 1. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, equal with 38000, and the value of E is less than 0.03.

Example 9

Repeat step for crude ε-caprolactam example 1.

Stage crystallization of example 1 is repeated, except that used for crystallization of n-chlorobutane instead of isopropyl ether as a solvent in the amount of 2.0 kg of the Thus obtained 1,90 kg 99,92% crystalline ε-caprolactam and 2.10 kg 95,8% n-chlorobutane.

Repeat stage leaching of example 1, the claim is ucheniem, what used to wash the n-chlorobutane instead of isopropyl ether as a solvent in the amount 1,90 kg Thus receive 99.97% of the crystalline ε-caprolactam and 98.8% of the n-chlorobutane (containing, in addition, 1,10% ε-caprolactam). The obtained ε-caprolactam is the absorbance value of the RM, is equal to 145, and the value E is less than 0.5.

Stage hydrogenation

1,90 kg of 99.97% crystalline ε-caprolactam, washed once with n-chlorbutanol make a 10 l reactor, type of 4.44 kg of water and 190 g of amorphous catalyst for hydrogenation (commercial trademark of SRNA-4 and commercially available in the petrochemical Corporation JianChang in Hunan, China). The reaction mixture is heated to approximately 100°C, the hydrogen purge with a controlled flow rate of 0.6 l/min and the pressure during the reaction is 7 MPa, so that an aqueous solution of crystalline ε-caprolactam was in contact with hydrogen, reacting for one hour. After evaporation in trehkorpusny apparatus and distillation in a vacuum at approximately 1 mm Hg receive 1.86 kg of ε-caprolactam. The yield is 98%. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal 39000 with, and the value of E is less than 0.02.

Example 10

Repeat step for crude ε-caprolactam example 1.

Stage crystallization of example 1 is repeated, except that the COI is lsout for crystallization 1-rambutan instead of isopropyl ether as a solvent in the amount of 2.0 kg So get 1,80 kg 99,90% crystalline ε-caprolactam and 2.18 kg 95.6% of 1-bromobutane.

Repeat stage leaching of example 1, except that used for washing 1-rambutan instead of isopropyl ether as a solvent in the amount of 2.0 kg of the Thus obtained 99.95% of crystalline ε-caprolactam and 98.5% of 1-bromobutane (containing, in addition, of 1.05% ε-caprolactam). The obtained ε-caprolactam is the absorbance value of the RM equal to 95 C, and the value of E is less than 0.6.

Repeat stage hydrogenation of example 1. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 26000, and the value of E is less than 0.05.

Example 11

Repeat step for crude ε-caprolactam example 1.

Stage crystallization of example 1 is repeated, except that used for crystallization of isolobodon instead of isopropyl ether as a solvent in the amount of 4.0 kg of the Thus obtained 1.86 kg 99,93% crystalline ε-caprolactam and 4.10 kg 95.6% of isoflorane.

Repeat stage leaching of example 1, except that used for washing isobarbaloin instead of isopropyl ether as a solvent in the amount of 2.0 kg of the Thus obtained 99.95% of crystalline ε-caprolactam and 99.0% isoflorane (containing, in addition, 0,96% ε-caprolactam). The obtained ε-kaprol there is the absorbance value of the RM, equal to 110 C, and the value of E is less than 0.6.

Repeat stage hydrogenation of example 1. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 33000 from, and the value of E is less than 0.04.

Example 12

Repeat step for crude ε-caprolactam example 1.

Stage crystallization of example 1 is repeated, except that used for crystallization of trichlormethane instead of isopropyl ether as solvent. The output obtained ε-caprolactam after crystallization amounted to 83.5% and purity 99,68%.

Repeat stage leaching of example 1, except that used for washing trichlormethane instead of isopropyl ether as solvent. The output obtained ε-caprolactam after washing was 98.4% and 99.95%. The obtained ε-caprolactam is the absorbance value of the RM, is equal to 76, and the value of E is less than 0,80.

Repeat stage hydrogenation of example 1. After analysis of the received end-ε-caprolactam is the absorbance value of the RM, is equal to 28000, and the value of E is less than 0.05.

1. The method of purification of crude ε-caprolactam obtained from cyclohexasiloxane a Beckmann rearrangement in the gas phase, which includes a step of crystallization of ε-caprolactam from a solution of the crude ε-caprolactam in a simple ether or halogenated hydrocarbon, stage leaching solvent crystallizes the CSOs ε-caprolactam, obtained at the stage of crystallization and phase hydrogenation of crystalline s-caprolactam by contacting with hydrogen in the presence of a hydrogenation catalyst.

2. The method according to claim 1, in which the specified Beckmann rearrangement is carried out in the presence as catalyst of molecular sieves with the MFI structure, and in which the solvents for the reaction are alcohols.

3. The method according to claim 2, in which the specified solvent for the reaction is methanol or ethanol.

4. The method according to any one of claims 1 to 3, wherein said crude ε-caprolactam is obtained by distillation of a liquid mixture of solvent and ε-caprolactam obtained by the specified reaction.

5. The method according to any one of claims 1 to 3, wherein said solution get mixing crude ε-caprolactam in the molten state with a simple ether or halogenated hydrocarbon as a solvent for carrying out crystallization.

6. The method according to any one of claims 1 to 3, which are specified as simple solvent ether or halogenated hydrocarbon are evaporating temperature range from 30 to 150°C, and they are used in quantities of from 0.3 to 3 parts by weight part of the ε-caprolactam.

7. The method according to claim 6, in which are specified as simple solvent ether or halogenated hydrocarbon are evaporating temperature range from 30 to 120°C, and their use is the amount of from 0.6 to 1.5 parts on the weight part of the ε-caprolactam.

8. The method according to claim 7, in which are specified as simple solvent ether or halogenated hydrocarbon are evaporating temperature range from 60 to 100°C., and they are used in quantities of from 0.8 to 1.2 parts by weight part of the ε-caprolactam.

9. The method according to any one of claims 1 to 3, which is specified as a simple solvent ether selected from the group consisting of normal simple ether, simple branched ether, simple diapir, a partial ester of a polyhydric alcohol and ethers of olefins, and specified as a solvent, halogenated hydrocarbon selected from the group consisting of normal halogenated hydrocarbon, branched halogenated hydrocarbon, dehalogenating hydrocarbon and trihalomethanes hydrocarbon.

10. The method according to claim 9, wherein said as solvent a simple ether selected from the group consisting of ethyl ether, n-propyl ether, isopropyl ether, n-butyl ether, motivational ether, ethylbutylamine ether, dimethyl ether glycol vinyl ether, methyl tertiary butyl ether and ethylcellulose ether, and which is specified as a solvent, halogenated hydrocarbon selected from the group consisting of n-chloropropane, isolabona, n-chlorobutane, 2-chlorobutane, isobarbaloin tertbutylamine, n-bromopropane, sobrepena, 1-bromobutane and 2-bromobutane.

11. The method according to any one of claims 1 to 3, in which the specified stage of crystallization is conducted only once and if necessary, enter the seed.

12. The method according to any one of claims 1 to 3, in which the specified stage crystallization is carried out at a temperature in the range from -10°C up to the melting point of the ε-caprolactam.

13. The method according to item 12, in which the specified stage crystallization is carried out at a temperature in the range from 20°C to the melting point of the ε-caprolactam.

14. The method according to any one of claims 1 to 3, in which the solvent used for washing, represents the same or another solvent as the solvent used for crystallization, and the solvent used for washing is selected from the group consisting of ethers, halogenated hydrocarbons, normal waxes and cycloparaffins.

15. The method according to any one of claims 1 to 3, in which the specified hydrogenation catalyst is a catalyst made of amorphous Nickel.

16. The method according to any one of claims 1 to 3, wherein said ε-caprolactam is brought into contact with hydrogen in the molten state, an aqueous solution or organic solution.

17. The method according to any one of claims 1 to 3, in which the specified stage hydrogenation is carried out in a slurry reactor, a reactor with a fixed layer or the reactor with magnetic stable the data layer.

18. The method according to any one of claims 1 to 3, in which the specified stage hydrogenation is carried out at reaction conditions including a temperature of 80-150°C. and a pressure of 2-15 ATM.

19. The method according to any one of claims 1 to 3, in which the final ε-caprolactam contains less than 10 μg/g cyclohexasiloxane, less than 10 μg/g 1,2,3,4,6,7,8,9-octahydrophenanthrene and less than 30 μg/g capreolata and its structural isomers.



 

Same patents:

FIELD: medicine, pharmaceutics.

SUBSTANCE: invention refers to compounds of general formula

where there are R3/R3', R4/R4' and R5/R5' where at least one of either R4/R4' or R5/R5' always represents a fluorine atom, and the other radical values are disclosed in the description.

EFFECT: making the compounds which are γ-secretase inhibitors, and can be effective in treating Alzheimer's disease or advanced cancers, including but not limited to carcinoma of uterine cervix and breast carcinoma and malignant tumours of hematopoietic system.

15 cl, 3 tbl, 18 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for synthesis of caprolactam from alkylcyanovalerate which involves bringing alkylcyanovalerate into contact with hydrogen in gaseous state in the presence of a hydrogenation catalyst and a ring formation catalyst, and treatment after condensation of a gaseous stream containing the formed lactam in order to separate ammonium which may be present, the formed alcohol and/or the caprolactam solvent and extraction of caprolactam, where the hydrogenation catalyst includes a metal element or a mixture of metal elements selected from a group containing an active metal element in form of iron, ruthenium, rhodium, iridium, palladium, cobalt, nickel, chromium, osmium and platinum or several metals from this list, and the ring formation catalyst is porous aluminium oxide.

EFFECT: obtaining caprolactam without intermediate separation of alkylaminocaproate.

10 cl, 5 ex, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to derivatives of 3-aminocaprolactam of formula (I): , where X represents -CO-R1 or -SO2-R2, R1 represents alkyl (with the exception of 5-methylheptanyl and 6-methylheptanyl, where radical R1 is bonded to carbonyl in position 1), halogenalkyl, alkoxy (with the exception of tret-butyloxy), alkenyl, alkinyl or alkylamino radical from 4-20 carbon atoms (for example, from 5-20 carbon atoms, 8-20 carbon atoms, 9-20 carbon atoms, 10-18 carbon atoms, 12-18 carbon atoms, 13-18 carbon atoms, 14-18 carbon atoms, 13-17 carbon atoms) and R2 is alkyl radical from 4-20 carbon atoms (for example, from 5-20 carbon atoms, 8-20 carbon atoms, 9-20 carbon atoms, 10-18 carbon atoms, 12-18 carbon atoms, 13-18 carbon atoms, 14-18 carbon atoms, 13-17 carbon atoms); or to its pharmacologically acceptable salt. Invention also relates to application and pharmacological composition, which has anti-inflammatory activity, based on said compounds.

EFFECT: obtaining new compounds and based on them pharmacological composition, which can be applied for obtaining medications for treatment, relief or prevention of inflammatory disease symptoms.

57 cl, 62 ex

FIELD: chemistry.

SUBSTANCE: invention refers to bengamide derivatives produced by fermented microorganism Myxococcus virescens ST200611 (DSM 15898), to application in cancer therapy and/or prevention, to medical products containing bengamide derivatives, making process of bengamide of formula . In addition, the invention refers to compound of formula .

EFFECT: new bengamide derivatives are characterised with useful biological properties.

15 cl, 7 tbl, 18 ex

FIELD: organic chemistry, medicine, biochemistry, pharmacy.

SUBSTANCE: invention relates to novel azaheterocycles of the general formula (I): possessing inhibitory effect on activity of tyrosine kinase and can be used in treatment of different diseases mediated by these receptors. In compound of the general formula (1) W represents azaheterocycle comprising 6-13 atoms that can be optionally annelated with at least one (C5-C7)-carbocycle and/or possibly annelated with heterocycle comprising 4-10 atoms in ring and comprising at least one heteroatom chosen from oxygen (O), sulfur (S) or nitrogen (N) atom; Ra1 represents a substitute of amino group but not hydrogen atom, such as substituted (C1-C6)-alkyl, possibly substituted aryl and possibly substituted 5-10-membered heterocyclyl comprising at least one heteroatom chosen from O, S or N; Rb represents carbamoyl group -C(O)NHRa wherein Ra represents a substitute of amino group but not hydrogen atom, such as possibly substituted alkyl, possibly substituted aryl, possibly substituted 5-10-membered heterocyclyc comprising at least one heteroatom chosen from O, S or N; Rc represents a substitute of cyclic system, such as possibly substituted (C1-C6)-alkyl, possibly substituted aryl and possibly substituted 5-6-membered heterocyclyl comprising at least one heteroatom chosen from O, S or N; or Rb and Rc form in common aminocyanomethylene group [(=C(NH2)CN], or their pharmaceutically acceptable salts. Also, invention relates to methods for synthesis of these compounds (variants), a pharmaceutical composition, combinatory and focused libraries.

EFFECT: valuable medicinal properties of compounds and pharmaceutical composition, improved methods for synthesis and preparing.

35 cl, 16 sch, 13 tbl, 43 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to technology for preparing caprolactam by the cyclization reaction of derivatives of aminocaproic acid. Method is carried out by cyclizing hydrolysis of compound chosen from the group comprising aminocaproic acid esters or amides, or their mixtures. The process is carried out in the presence of water, in vapor phase at temperature 200-450°C in the presence of a solid catalyst comprising of aluminum oxide that comprises at least one macroporosity with pores volume corresponding to pores with diameter above 500 Å taken in the concentration 5 ml/100 g of above. Preferably, the specific square of catalyst particles is above 10 m2/g and the total volume of pores is 10 ml/100 g or above wherein pores volume corresponds to pores with diameter above 500 Å is 10 ml/100 g or above. Invention provides improving the process indices due to the improved properties of the solid catalyst.

EFFECT: improved preparing method.

5 cl, 2 ex

FIELD: chemistry of lactams' derivatives.

SUBSTANCE: the present innovation deals with obtaining N-(2-chloroalkyl)- and N-alkyl-aromatic derivatives of lactams of the following general formula: , where R=H, Cl, R'=(CH2)3, (CH2)5 which could be modifiers of unsaturated carbon-chain caoutchoucs and rubber mixtures based upon them. The suggested method for obtaining the mentioned N-substituted lactams deals with combining N-chlorolactams and allyl benzene, moreover, as N-lactams one should apply either N-chlorobutyrolactam or N-chlorocaprolactam. The process should be carried out at molar ratio of N-chlorolactam to allyl benzene being equal to 1-1.15:1, at availability of a catalyzer as mono-tertiary-butylperoxy-α-methylmethoxyethoxyethyl ether of ethylene glycol taken at the quantity of 0.4-4.0% weight, in the medium of inert solvent, for example, chlorobenzene at 100-125° C for about 15-20 min. The innovation enables to shorten terms of reaction by 20-30 times, simplify the way for obtaining target products and widen the assortment of the obtained compounds, as well.

EFFECT: higher efficiency.

The invention relates to a method of evaporation aminonitriles and water in the synthesis of lactam by the reaction between aminonitriles and water in the vapor phase in the presence of a catalyst of aluminum hydroxide

The invention relates to the protection of building materials and structures from the biodegradation of microscopic mushrooms

The invention relates to acylaminocinnamic derivative of the formula (I), where R denotes phenyl which is not substituted or may be substituted with halogen, alkyl, trifluoromethyl, hydroxy and alkoxygroup, R1is hydrogen, alkyl, R2is hydrogen, alkyl or phenyl which is not substituted or may be substituted with halogen, alkyl, trifluoromethyl, hydroxy and alkoxygroup, R3is phenyl which is not substituted or may be substituted with halogen, alkyl, trifluoromethyl, hydroxy and alkoxygroup, or represents naphthyl, lH-indol-3-yl or 1-alcheringa-3-yl, R4' and R4"is hydrogen, alkyl, and one of the radicals R4' and R4"is hydrogen, and R5- cycloalkyl, D-azacycloheptan-2-he-3-yl or L-azacycloheptan-2-he-3-yl, or its salt

The invention relates to the processing of lactams
The invention relates to the separation of water from an aqueous solution of lactam

The invention relates to a method of purification of lactams by liquid-liquid extraction and/or processing using ion exchange resin
The invention relates to the processing of lactams directly after their synthesis in the reaction stream resulting from the hydrolysis and cyclization of aminonitriles, for example, containing caprolactam

The invention relates to a method for continuous purification of crude caprolactam obtained by the interaction of 6-aminocaproate with water
The invention relates to the field of adsorption technology

FIELD: chemistry.

SUBSTANCE: invention refers to the method for operating mode of caprolactam production from benzene carried out in the plant with one process line including the stations of benzene hydrogenation with hydrogen, cyclohexane oxidation with oxygen, cyclohexanone rectification, oximation, cyclohexanone oxim rearrangement to caprolactam, neutralisation of the reaction mixture with ammonia and mixing of caprolactam. The said stations are connected with pumps, pipelines with sensors and valves for consumption control of benzene, hydrogen, cyclohexanone, hydroxylamine sulphate and oleum, sensor of acid value and pH-metre of caprolactam. The said line contains additionally the second process line of caprolactam production from phenol including the stations of phenol hydrogenation with hydrogen, dehydrogenation of cyclohexanol with circulation circuit including: pump - station of cyclohexanol dehydrogenation - station of cyclohexanone rectification - pump, station of cyclohexanone rectification, oximation with hydroxylamine sulphate, rearrangement of cyclohexanon oxim to caprolactam and neutralisation of the reaction mixture with ammonia connected by pumps and pipelines with sensors and valves for control of benzene, hydrogen, cyclohexanone, hydroxylamine sulphate and oleum consumption, sensor of acid value and pH-metre of caprolactam and contains the device of benzene-phenol ratio connected with stations of benzene and phenol hydrogenation, oxidation and dehydrogenation; device of cyclohexanone distribution to the oximation stations connected with rectification stations and (through the cyclohexanone mixing tank) with the oximation stations; device of crystalline caprolactam switch-over to liquid caprolactam connected with caprolactam mixer, concentrator of crystalline caprolactam and tank of liquid caprolactam. The total caprolactam capacity, benzene-phenol ratio, cyclohexanone distribution to oximation stations, shipping of crystalline and liquid caprolactam to customers are set up; the consumption of benzene, phenol, hydrogen, cyclohexanone, hydroxylamine sulphate and oleum are corrected with corresponding valves.

EFFECT: enhancing of productivity and caprolactam quality.

9 cl, 1 ex, 1 tbl, 3 dwg

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