KR100205132B1 - Process for treating amide - Google Patents

Abstract

The present invention relates to ketoxime or aldoxin-containing, in which the oxime containing amide mixture has a hydrolysis reaction and the reaction product is separated from the corresponding amide and is subjected to a Beckman rearrangement of the corresponding ketoxime or aldoxim to the oxidization reaction. A method for treating amide mixtures.

The caprolactam produced in the catalytic rearrangement of cyclohexanone oxime is actually completely free of oxime with the application of the process according to the invention.

Description

Amide Treatment

The present invention relates to a process for treating a ketoxime or aldoxime containing amide mixture obtained by rearranging the ketoxime or aldoxime with Beckman.

This method is known from GB-A-1,286,427.

In this patent application it is described to supply gaseous sulfur dioxide from caprolactam to remove cyclohexanone greed and to dissolve gaseous sulfur dioxide in a cyclohexanone oxime-containing caprolactam mixture at a temperature of 70-170 ° C.

Sulfur dioxide is dissolved at a concentration of at least 1 mole sulfur dioxide per mole of cyclohexanone oxime.

After completion of the reaction of the remaining cyclohexanone oxime with sulfur dioxide, excess sulfur dioxide is removed from the reaction mixture by evaporating sulfur dioxide under reduced pressure or by supplying an inert gas to the reaction mixture.

Purified caprolactam is subsequently recovered by distillation.

A disadvantage of this process is that the product formed by the reaction of ketoxime or aldoxime with sulfur dioxide is a material which is not suitable for the process, which must be removed from the process as a result.

The latent amount of amide formed, ie unrearranged ketoxime or aldoxim, is recovered in the process.

It is an object of the present invention to provide a simpler process that does not produce a material that is not bonded to the process as a reaction product.

The object is achieved in accordance with the process of the present invention by the ketoxime or aldoxime-containing amide mixture being hydrolyzed and the hydrolysis reaction product separated from the corresponding amide and an oxidization reaction taking place.

Hydrolysis reaction is understood to mean the reaction of water shells known to those skilled in the art in this regard.

The ketoxime or monoxin core used is converted by reaction with water to form hydroxylamine and the corresponding ketone or aldehyde.

For example, it is generally known in the art to prepare lactams, amides, for example ε-caprolactam, by homogeneous catalytic Beckman rearrangement of ketoxime or aldoxim, such as cyclohexanone oxime.

The rearrangement is accomplished by treating ketoxime or aldoxime with strong acids such as, for example, sulfuric acid, oleum, chlorosulfonic acid, hydrogen fluoride, phosphoric acid, phosphorus pentachloride and the like.

When used, for example, sulfuric acid or oleum, sulfuric acid-amide complexes are obtained after rearrangement whereby the preferred amides are usually recovered by neutralizing the reaction mixture with ammonia water and in this process large amounts of ammonium sulfate are obtained as by-products.

Another more preferred process is the heterocatalytic Beckman rearrangement using a solid acid or neutral catalyst as the corresponding amide, for example by rearrangement in the gaseous or liquid phase, to the corresponding amide of the ketoxime or aldoxim. It is a transition.

Examples of solid acids or neutral catalysts used are carriers such as silica or alumina and crystalline silica, i.e., silicate I (ZSM5 is silicon-rich MFL, also known as zeolite) and silicate II (silicon-rich MEL, also known as ZSM11 zeolite). But is boric acid on a carrier such as an acid ion exchanger or (mixed) metal oxide.

Advantageously, no ammonium sulfate is formed as a byproduct in the process.

In this Beckman rearrangement process, however, incomplete conversion of the ketoxime or single reading can occur, leaving the reactor with a significant amount of unreacted ketoxime or aldoxime formed amide.

Alternatively, the complete removal of the ketoxime or aldoxime from the oxime containing amide mixture is very necessary to obtain a high degree of amide purity in the amide preparation and to eliminate interference in subsequent amide preparation processes.

Separation of the oxime from the oxime containing amide mixture by current physical separation techniques is very difficult and can only be realized at high cost (cf. GB-A-1,286,427). The hydrolysis reaction of the -containing amide mixture can be made simply oxime free (100 ppm).

Examples of ketoxime or aldoxin in a ketoxime or aldoxin-containing amide mixture treated according to the invention and obtainable from Beckman rearrangement are saturated and unsaturated, substituted or unsubstituted aliphatic ketoxime or aldoxin or 2- Cyclic ketoximes having 12 carbon atoms, such as acetone oxime, acetaldehyde oxime, benzal oxime, propanoxime, butanal oxime, butanone oxime, buten-1-one oxime, cyclopropa oxime, cyclohexanone oxime , Cyclooctane includes oxime, cyclododeca includes oxime, cyclopentanone oxime, cyclodocene includes oxime, 2-phenylcyclohexanone oxime, cyclohexenone oxime.

According to the process according to the invention the hydrolysis reaction is carried out at a temperature between 50-150 ° C., preferably between 80-120 ° C.

Even if the hydrolysis reaction can be carried out not only under acidic conditions but also under base and neutral conditions, the reaction preferably takes place in acidic conditions.

Acids used are, for example, strong mineral acids or organic acids, such as sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, trifluoro acetic acid, aromatic sulfonic acids such as p-toluene sulfonic acid, benzenesulfonic acid.

Preference is given to using sulfuric acid, phosphoric acid or mixtures of these substances.

In hydrolysis under acidic conditions ph is 0-4 and preferably 1.5-2.5.

ph is related to the feed water here.

The hydrolysis reaction can be carried out batchwise as well as in a continuous process optionally in the presence of a heterogeneous catalyst.

The heterogeneous catalyst may be phosphoric acid absorbed on a carrier such as carbon black or silica.

Preferably the heterocatalyst is an acid cation exchanger.

The amide treated after the hydrolysis reaction preferably has an oxime content not higher than 0.01% (weight), or 100 ppm.

Under the process conditions of the process according to the invention the hydrolysis rate of ketoxime or aldoxim is several times higher than the hydrolysis rate of the corresponding amide.

The reaction-rate constant k (oxime) / k (amide) ratios involved in the temperature range and ph range used in the present invention are higher than 10,000 depending on the amount of water used, so that ketoxime or aldoxim The resulting amide can be degraded almost completely without being properly converted.

The amount of water used is not critical.

The process according to the invention requires at least an amount of water equal to the remaining oxime and it is convenient to use excess water, for example 10-100 equivalents.

Rearrangement of the ketoxime or aldoxime to form the corresponding amide can be carried out to a low degree of conversion, eg 75% conversion, if so desired.

Preference is given to converted rearrangements up to at least 890% and more specifically up to at least 95%.

Regardless of the percent conversion associated with the rearrangement, the resulting oxime hydrolysis product, ie the corresponding alkanone or aldehyde and hydroxyl amine, is hydrolyzed in a manner known to those skilled in the art, for example by distillation. It can be separated during or after the decomposition reaction.

The products can advantageously be returned to the oxime manufacturing process, also referred to as oxidization, and rearrangement proceeds.

Loss of oxime in the process can be avoided as a result.

The hydrolysis products of the converted amides can also be obtained after hydrolysis of the caprolactam mixture containing cyclohexanone oxime, such as for example ε-amide capric acid, and can be converted back to the corresponding amide, for example by raising the temperature. .

This does not include any loss of ketoxime or single reading and no loss of amide.

As a result, optimum efficiency is obtained.

Hydrolysis of ketoxime or aldoxim to form the corresponding alkanones or aldehydes and hydroxyl amines is described in US Pat. No. 4,349,520.

The patent application however does not describe the hydrolysis of ketoxime or aldoxin containing amide mixtures.

The present invention is not limited herein at present but is illustrated by representative embodiments.

Example 1

The caprolactam mixture was hydrolyzed with a residence time of 100 seconds and contained 30,000 ppm cyclohexanone oxime and 0.01 kg / sec phosphoric acid-containing water (10% by weight based on cyclohexanone oxime-containing caprolactam mixture). Continue feeding the 15 L reactor, stirred at 100 ° C, in kg / sec.

The outflow means that the caprolactam reference part 417 ppm cyclohexanone oxime and the anhydrous system reference 96.86% (weight) contain prolactam and 98.6% of the cyclohexanone oxime present is converted to hydroxyl amine and cyclohexanone. do.

Also, only 0.14% of the caprolactam present is converted to ε-aminocaproic acid.

The caprolactam mixture is hydrolyzed once again under the same conditions in a 15 L reactor containing a small amount of cyclohexanone oxime and in a second stirrer.

The effluent contained only 5 ppm cyclohexanone oxime with caprolactam reference and 96.71% caprolactam with anhydrous system reference, with 98.65% cyclo hexa remaining in the feed converted only 0.15% of oxime and caprolactam in this second stage .

The 0.29% caprolactam total amount is converted to ε-aminocaproic acid.

During the quality improvement by distillation with purified caprolactam, the [epsilon] -aminocaproic acid is converted back to the same amount of caprolactam, resulting in no loss of product.

Example 2

Example 1 is repeated but at this time the hydrolysis reaction is carried out at 95 ° C. with 30% sulfuric acid-containing based on cyclohexanone oxime-containing caprolactam mixture mixture.

The effluent from the second reactor contains only 10 ppm cyclohexanone oxime based on caprolactam.

The total amount of 0.19% caprolactam is converted into ε-aminocaproic acid.

Example III

Example 1 is repeated but the hydrolysis reaction is carried out at pH 2 with 5% (by weight) phosphoric acid-containing based on cyclohexanone oxime-containing caprolactam mixture. The effluent from the second reactor contained only 25 ppm cyclohexanone oxime by caprolactam reference.

The total amount of 0.29% caprolactam was converted to ε-aminocaproic acid and again converted to the same amount of caprolactam on quality improvement by distillation.

Example 4

Example 2 is repeated, wherein the hydrolysis reaction is carried out at pH 2.

The effluent from the second reactor contains only 40 ppm cyclohexanone oxime calculated on caprolactam.

The total amount of 0.19% caprolactam is converted into ε-aminocaproic acid.

Example 5

Example 1 is repeated, where the hydrolysis reaction is carried out to pH2.2 in a 75 L reactor using 20% (weight) phosphoric acid-containing water based on cyclohexanone oxime-containing caprol mixture under 500 sec residence time. .

The effluent contains only 3 ppm cyclohexanone oxime by caprolactam reference.

The total amount of 1.42% caprolactam is converted to ε-aminocaproic acid and converted back to caprolactam upon quality improvement by distillation.

Example 6

Although Example 2 is repeated. At this time, the hydrolysis reaction is performed at pH 2.2 in a 75 L reactor under 500 sec residual time.

The effluent from the second reactor contains only 4 ppm cyclohexanone oxime with caprolactam reference.

The total amount of 0.95% caprolactam is converted to ε-aminocaproic acid.

Example 7

The 0.1 kg / sec caprolactam mixture of Example 1 with 0.02 kg / sec water was fed to a packed column sifted with a 25 kg ion exchanger.

The reaction temperature is 100 ° C.

The effluent contained only 48 ppm cyclohexanone oxime by caprolactam reference.

The 0.15% caprolactam total amount was converted to ε-aminocaproic acid.

Example 8

Example 1 is repeated but at this time 30% (weight) F-toluenesulfonic acid-containing based on 30,000 ppm N-methylacetamide mixture containing acetone oxime and acetone oxime-containing N-methyl acetamide mixture at pH 2 The hydrolysis reaction is carried out at 95 ° C with the containing N-methylacetamide mixture.

The effluent only contains 14 ppm acetone oxime based on N-methylacetamide.

The 0.25% N-methylacetamide total is converted to formic acid and methylamine:

Upon improvement of the quality of the hydrolysis mixture by distillation it is converted to form N-methylacetamide again.

Example 9

Example 1 was repeated, but at 100 ° C. using 30% (weight) P-toluenesulfonic acid-containing based on a 2-butanone oxime containing N-ethylacetamide mixture with 30,000 ppm 2-butanone oxime and pH 2 Carried out under temperature.

The effluent from the second reactor contains only 23 ppm 2-butanone oxime based on N-ethylacetamide.

The total amount of 0.14% ethyl acetamide is converted to methyl amine acetate.

Example 10

Example 1 is repeated but the hydrolysis reaction is carried out with a laurinolactam containing 30,000 ppm cyclododecanone oxime and 30% (weight) phosphoric acid-containing water in a 75 L reactor.

The effluent only contains 18 ppm cyclododecanone oxime mom by laurinolactam reference.

The 0.22% laurinolactam total amount is converted to ω-amino dodecanoic acid.

The practice clearly shows that the ketoxime or aldoxim containing amide mixture can be obtained almost completely without oxime after the hydrolysis reaction, while the converted amine can be recovered again in the same amount.

Claims (7)

In the process for treating a ketoxime or aldoxime-containing amide mixture obtained by a Beckett rearrangement of the corresponding ketoxime or aldoxim, the ketoxime or aldoxin-containing amide mixture undergoes a hydrolysis reaction and the hydrolysis reaction. A process for treating a ketoxime or aldoxin-containing amide mixture, wherein the product is separated from the corresponding amide and subjected to an oxidization reaction. The method of claim 1 wherein the hydrolysis reaction occurs at pH 0-4. The method of claim 2 wherein the hydrolysis reaction occurs at pH 1.5-2.5. The process according to any one of claims 1 to 3, wherein the hydrolysis reaction takes place at a temperature of 50 to 150 ° C. The method of claim 4, wherein the hydrolysis reaction occurs at a temperature of 80 ~ 120 ℃. 8. The method according to any one of claims 1, 2, 3 and 7, wherein the ketoxime is cyclohexanone oxime. The method according to any one of claims 1, 2, 3, 4, 5, 6, wherein the ketoxime or monoxin-containing amide mixture is obtained by rearrangement of heterocatalytic backlinks only. Process for treating ketoxime or aldoxime-containing amide mixture.