DE1192649B - Process for the production of omega-laurolactam - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

C07d

German class: 12p -5

Number: 1192 649

File number: B 60753IV d / 12 ρ

Filing date; January 7, 1961

Open date: May 13, 1965

It is known that ω-laurolactam is obtained when using Beckmann's cyclododecanone oxime Subjected to rearrangement with sulfuric acid. The starting material required for this must be cyclododecanone oxime be prepared in a relatively cumbersome way, namely either by acyloin condensation of Decanedicarboxylic acid to cyclododecanolone, partial reduction to cyclododecanone and implementation of the the latter with hydroxylamine to the oxime or by trimerization of butadiene to cyclododecatriene, Epoxidation and hydrogenation to epoxycyclododecane, isomerization to cyclododecanone and finally Conversion of the latter to the oxime. Recently, a method has been described in which the Trimerization of butadiene and subsequent hydrogenation of accessible cyclododecane with nitrosating Agents, such as nitrosyl chloride, with simultaneous exposure, optionally in the presence of Hydrogen chloride, is converted directly to the cyclododecanone oxime hydrochloride.

All of these methods have the disadvantage that they can be carried out over several stages, sometimes with moderate yields lead to ω-laurolactam. Furthermore, the lactam obtainable by this process is often sufficient not the purity requirements to be placed on a starting product for valuable polyamides, so that the lactam still has to be purified by additional measures.

It has now been found that ω-laurolactam can be obtained in high yields in a simpler manner if an excess of nitrosating agents up to a molar ratio of 1: 2 at temperatures of 35 to 150 is used on cyclododecanecarboxylic acid or its salts, preferably alkali or alkaline earth salts ⁰ C in the presence of sulfuric acid and / or oleum can act.

The ω-laurolactam obtainable in one step from the cyclododecanecarboxylic acid already has in In its raw state, it has such a high degree of purity as none of the others has been known to date Procedure is to be obtained.

For the preparation of the cyclododecanecarboxylic acid used as the starting material, z. B. from that Cyclododecatriene obtainable by trimerization of butadiene start, this by oxo synthesis convert in a known manner into monohydroxymethylcyclododecane and then oxidize to the carboxylic acid, for example by the known method of oxidative alkali melt.

As nitrosating agents in the process of the invention, for example, nitrosylsulfuric acid, Process for the production of ω-laurolactam

Applicant:

Aniline & Soda Factory in Baden

Aktiengesellschaft, Ludwigshafen / Rhein

Named as inventor:

Dr. Horst Metzger, Ludwigshafen / Rhine;

Dr. Hans Urbach, Lampertheim

Nitrosyl sulfuric anhydride, nitrosyl chloride, sodium nitrite, Alkyl nitrites or nitrous oxide are used. Nitrosylsulfuric acid is preferably used or its anhydride, the z. B. also by heating nitrosylsulfuric acid in sulfuric acid and / or oleum produced and used directly in this form without further isolation can be.

The ratio of cyclododecanecarboxylic acid to sulfuric acid can vary within wide limits are, however, at least 1 mole of sulfuric acid should be used per mole of cyclododecanecarboxylic acid will. If one assumes an alkali or alkaline earth metal salt of the carboxylic acid, the ratio should be Salt to sulfuric acid must be at least 1: 2. If you use nitrosating agents that differ from Derive sulfuric acid, like nitrosylsulfuric acid or its anhydride, so is the contained therein Sulfuric acid to be taken into account in the calculation.

The sulfuric acid concentration can also

vary within wide limits. It is advisable to use a 100% sulfuric acid, so-called Monohydrate and / or oleum, ie a sulfuric acid, which is up to about 65 percent by weight Contains dissolved sulfur trioxide. But you can also use a water-based (e.g. 80%) Sulfuric acid carry out the reaction; in this case, however, longer reaction times are required with a lower conversion and higher reaction temperatures required.

The optimum reaction temperature can be determined with a given acid concentration and concentration Easily determine nitrosating agents by means of a preliminary test. You can see the progress of the implementation in a clear, but not too violent, formation of carbon dioxide and in the fact that heat of reaction becomes free, which may have to be removed by cooling. To better initiate the reaction you can use a small amount, e.g. B. add 10 percent by weight of laurolactam or

509 569/358

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sedimentation mixture temporarily to slightly higher cyclohexanecarboxylic acid with excess nitrosyl

Temperatures up to the noticeable onset of sulfuric acid compared to that during the implementation

Reaction, heat. The beginning of the reaction has decreased as the yield obtained in molar amounts. Against it

Detect formation of carbon dioxide. the relative yield of ω-laurolactam increases

A preferred embodiment of the process 5 of the treatment of cyclododecanecarboxylic acid with

consists in that the nitrosating agent, dissolved excess nitrosylsulfuric acid or remains

in sulfuric acid and / or oleum, in a solution at least the same size.

of the cyclododecanecarboxylic acid or its salts in The ω-laurolactam obtained according to the invention

Sulfuric acid or a solvent, e.g. B. Cyclo has a purity as it is with the known

hexane, enters to the extent that from the heated io process only after a cleaning process

Conversion mixture continuously escapes carbon dioxide. is to achieve.

When the addition of the nitrosating agent has ended. The parts given in the examples are

stir for a short time and pour the parts by weight,

mixed on ice or water. Example 1 falls here

the ω-laurolactam formed, possibly also 15

together with unreacted cyclododecan carbon- To a solution of 32.0 parts of cyclododecan

acid, without the reaction mixture previously carboxylic acid, _{boiling point 0f8} 163 to 165 ° C, melting point

must be neutralized. (recrystallized from glacial acetic acid) 98 ^° C., in 24.0 parts

However, one can also proceed in such a way that the 100% sulfuric acid is added, with thorough stirring, the nitrosating agent and the sulfuric acid separately, a nitrosation mixture consisting of 21.7 parts of each other, but at the same time for the useful 18.0 parts of 100% nitrosylsulfuric acid ^he sulfur-sulfuric acid or a solvent dissolved acid and 22.5 parts 65 ⁰ J ₀ IgQm. Oleum, which previously gives cyclododecanecarboxylic acid. Was stirred at 110 to 120 ° C for 1 hour.

In the case of continuous operation, after adding about 1 part of the nitrosation

advantageous in such a way that the solution of the cyclododecane mixture is heated, the reaction mixture is

carboxylic acid or its salt, the nitrosating agent visible, up to about 65 ⁰ C a carbon dioxide

and the sulfuric acid or the oleum jointly starts winding. Now it will be within 25 minutes

or separately but simultaneously in a sufficiently large residual Nitrosierungsgemisch at 55 to 6O ⁰ C

and a suitably heated reaction zone and then added and then stirred at 60 ° C until

depending on the reaction temperature, until no more carbon dioxide escapes. For this will be

corresponding residence time the mixture continuously needs about 20 minutes. The implementation mix

z. B. via an overflow removed. is now poured onto 160 parts of ice. Divorce here

After dilution with water from which crystals emerge, which predominantly consist of ω-laurolactam

Reaction mixture consist of precipitated and almost colorless crude; they are dissolved in chloroform. the

Lactam can be obtained by distillation, sublimation or 35 chloroform solution is made twice with 2N sodium hydroxide solution

can be purified by recrystallization. Contains shaken and evaporated to dry. as

the laurolactam with incomplete conversion of the residue gives 28.1 parts of practically colorless

nor cyclododecanecarboxylic acid, you can get the ω-laurolactam with a melting point of 150 to 151 ° C.

Laurolactam-cyclododecanecarboxylic acid mixture in By acidifying the alkaline extract and

an inert solvent, e.g. B. benzene or chloro-40 filter off the precipitate that forms

form, dissolve and the carboxylic acid from this is obtained after drying 0.65 part of cyclo-

Remove extraction with alkali and, if necessary, return dodecanecarboxylic acid with a melting point of 95 ° C,

by acidifying the alkaline extract back- The conversion of cyclododecanecarboxylic acid is

to win. However, one can also make the separation by accordingly 98% of theory. The yield of ω-lauric

Carry out distillation or recrystallization. 45 lactam, based on the cyclododecane carbon used

A process is already known, according to which acid amounts to 94% of theory,

ε-caprolactam is obtained when using cyclohexane. · 1 0

carboxylic acid in the presence of sulfuric acid and .Example λ

or or oleum treated with nitrosating agents. To a solution of 32.0 parts of cyclododecane

However, it was not foreseeable that this reaction would result in 50 carboxylic acid in 24.0 parts of 100% sulfuric acid

3 parts of ω-laurolactam are also added to the cyclododecanecarboxylic acid and its salts and then added

would be applicable because the cyclododecanecarbon- good stirring within 30 minutes at 55 to

acid in contrast to the cyclohexanecarboxylic acid with 6O ⁰ C a nitrosation mixture of 22.0 parts of nitro

Sulfuric acid or oleum for the reaction sylsulfuric acid, 20.0 parts of 65% oleum and

for the lactam required temperatures under vigorous 6.0 parts of 100% sulfuric acid, which was previously 1 hour

Reaction undergoes decomposition. Which had been heated to 120 ° C for a long time. After finished

According to the process, there is no decomposition of the cyclo- addition of the nitrosation mixture is stirred

dodecanecarboxylic acid, but is obtained over 50 minutes at 60 ° C., poured onto 160 parts of ice and

surprisingly, ω-laurolactam in yields up to proceed as described in Example 1. Man

96% of theory with practically quantitative conversions, 6 ° does not receive any cyclododecanecarboxylic acid back, i.e.

while with the known method of cooking the conversion was quantitative. Yield of practically

position of ε-caprolactam, starting from Cyclo colorlosema> -Laurinlactam30.5 parts (92% of theory);

hexanecarboxylic acid, yields of a maximum of 90% of the melting point 15O ⁰ C.

Theory at sales of 61% of theory or example 3

Yields of 85% of theory with conversions of 65

82% of theory received. Proceed as indicated in Example 1,

Comparative tests have shown that the relative uses 36 parts of the potassium salt of the cyclododecan

Yield of ε-caprolactam in the treatment of carboxylic acid in 25 parts of 100% sulfuric acid ^e r.

Claims (1)

When the reaction has ended, it is poured onto 160 parts of ice and the cu-laurolactam formed is separated off. Yield 31.1 parts (94% of theory). Example 4 A reaction vessel, which is provided with a stirrer and a heatable overflow tube of such a length that average residence times in the reaction vessel of about 40 minutes and in the overflow tube of about 15 minutes, is filled with a mixture of co-laurolactam and oleum, such as it in a previous approach, e.g. B. according to Example 1, has arisen. The mixture is heated to 55 to 6O ⁰ C and continuously per hour, a solution of 400 parts of nitrosylsulfuric acid in 700 parts of 45% oleum and at the same time 540 parts of molten Cyclododecancarbonsäure to. The mixture is heated or cooled in such a way that a temperature of 55 to 60 ^° C. is maintained in the reaction mixture. The reaction mixture running out of the overflow pipe is introduced into water with stirring and the crude ω-laurolactam which separates out is continuously spun off and washed with water. After drying, a crude lactam of melting point 150 ⁰ C in a yield of 95% of theory. A similar result is obtained if you add the ίο cyclododecanecarboxylic acid to the reaction mixture in the solid state, e.g. B. with the help of a dosing plate or a screw, or dissolved in z. B. 100% sulfuric acid clogs. Example 5 The procedure is as indicated in Example 1, but with the amounts indicated in the table below and times at the specified temperatures and receives the specified amounts of raw lactam. Ver Carboxylic acid Parts solved in parts Parts Nitrosyl sulfate Tempe Reak Lactam yield % the search H ₂ SO ₄ or oleum solved in parts rature ions theory No. 27.0 (Concentration) 16.3 H ₂ SO ₄ or oleum time in 92 20 (100%) (1: 1). (Concentration) ° C Minutes Parts a 27.0 24.5 35 (38% SO ₃ ) 60 50 23.0 95 20 (100%) (1: 1.5) b 27.0 20.0 35 (46% SO ₃ ) 50 65 23.7 94 20 (80%) (1: 1.2) C. 27.0 20.0 70 (50% SO ₃ ) 60 60 23.5 84 20 (10% SO ₃ ) (1: 1.2) d 27.0 20.0 35 (20% SO ₃ ) 20th 2100 21.0 93 150 (100%) (1: 1.2) e 27.0 18.0 13 (100+ 150/65% SO ₃ ) 60 75 23.2 88 20 (100%) (1: 1.1) f 30 (100%) 110 70 22.0 Example 6 Claim: A mixture of 55 parts of cyclododecanecarboxylic acid, 110 parts of 10% oleum and 40 parts of nitrosylsulfuric acid, freshly prepared at room temperature, is slowly entered at the top of a heatable, serpentine-shaped tube, which allows an average residence time of the reaction mixture of about 5 minutes and 80 at the top ° C and from the lower third to 130 ⁰ C is heated. The starting mixture is added in such a way that the development of carbon dioxide does not become too violent. The reaction mixture leaving the coiled tube at the bottom is stirred into water so that a maximum sulfuric acid concentration of 50% is produced. By filtering off, washing and drying the precipitated crystals, a crude laurolactam is obtained in 93% yield; F. = 150 ° C. Methods of preparing Cu-laurolactam, characterized in that on Cyclododecancarbonsäure or their salts, an excess of nitrosating agents to the molar ratio 1: 2 at temperatures of 35 to 150 ⁰ C in the presence of sulfuric acid and or or lets oleum take effect. Considered publications:
French Patent No. 1,238,981;
"Reports of the German Chemical Society", Vol. 41, 1908, pp. 1665 to 1672; "Helvetica Chimica Acta", Vol. 32, 1949, p. 544 to 552. 509 569/358 5. 65 © Bundesdruckerei Berlin