DE2347905A1 - METHOD FOR MANUFACTURING HEPTAMETHYLENIMINE - Google Patents

Description

PROCEDURE FOR THE MANUFACTURING OF HEPTAMETHYLENIMINE

_A 415-77

Several processes are known for the preparation of hexa- and eptamethyleneimine. (German Patent No. 1,138,780.) (6-, aminohexyl) -amine out steam at 320-340 ⁰ C by means of a dehydration catalyst (alumina, aluminum silicate) - Following a method is bis-. Another method is used to prepare cyclic amines from c ^ ui diamines with a Raney-Kickel catalyst (Nippon Kagaku Zashi 82 , / 1 ^ 61/1700). The target compounds were made from to-Ohlorönanthsäureamid, by the electrolytic reduction of

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Thiolactam and by the catalytic hydrogenation of Caprolactam methyl ether (J. Am. Chem. Soc. _ ££ / 1948/2115), and through catalytic hydrogenation with Haney nickel von bis-önantholactamftther (Hungarian patent specification No. 151 996). According to the method described in Hungarian Patent Specification No. 153,819, the target compound of önantholactain-O-methyl ether by reduction with Obtain sodium borohydride. Made from caprolactam and ünantholactam the cyclic imines were produced by a chemical reduction process (e.g. British patent specification No. 803 178).

Our invention relates to a process for the preparation of heptamethyleneimine by the reduction of önanthoIactarn characterized in that enantholactam is hydrogenated in a liquid or gas phase in the presence of a catalysis ier _/ crystallizer.

The hydrogenation is advantageously produced in the presence of a copper chromite catalyst .

An advantageous method for the preparation of the copper chromite catalyst is described in the following:

Solution A: 260 g copper (II) nitrate trihydrate and 31 g Barium nitrate in 900 cm of water at a temperature of 80 ° C.

Solution B: 151 S Animonium-di t chroma and 225 cnr of 28% ammonia diluted to 900 CIIR with water at a temperature of 25 ⁰ C

Solution A is poured into solution B, the resulting precipitate is filtered off, if possible until it is dry. Thereafter, the precipitate in a desiccator at 75-80 ⁰ C is dried for 12 hours and pulverized. The thermal decomposition was expediently carried out in three stages in a porcelain plate (15 cm 0) on an open fire. During the decomposition, the powder was constantly stirred and the flame was regulated in such a way that the evolution of gas did not become too strong. At low temperature, spontaneous decomposition follows. That can

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BATH ORIGINAL

The easiest way to achieve this is to heat only one side of the porcelain plate, and the intensity of the stirring is so increased that at the beginning of the decomposition the substance should be homogeneously mixed throughout the plate. During the thermal decomposition, the color of the powder changes from orange to brown, and at the end the color changes to black. When the whole powder becomes homogeneously black and no more gas develops, the powder is cooled down. The three parts are combined and the mixture is extracted with 600 cnr ⁵ 10% by weight for 30 minutes - stirred acetic acid.. It is filtered with 6x100 cn? Washed water, dried for 12 hours and pulverized at 125 G ^0. The yield is Ί ^ Ο g. In the event that the powder is tabletted, 5% by weight of graphite are added.

When operating in liquid-gas phase ·, it is favorable temperature range 180-220 ⁰ C and between 80-120 atm. to work. The method is advantageously carried out as follows.

A solution containing 5-25% by weight (expediently 15-20% by weight) alcohol is prepared from oenantholactam. The solution is placed in an autoclave and a catalyst, e.g. B. copper chromite in an O, 25-O_, 75 (expediently 0.5) fold amount added, calculated on the weight of the lactam. After purging with hydrogen, the autoclave is heated to 70-100 atm with hydrogen at room temperature. pressed, then ^{heated to 180-220 0} C and during. Shaking and stirring is hydrogenated for 2-8 hours. The rate of conversion or the reaction time depends on the rate of shaking, on the temperature and on the lactam / catalyst ratio. At the end of the reaction, the reaction mixture is separated from the catalyst.

If the reaction is carried out in the gas phase, the substance is expediently reacted ^{at atmospheric pressure and at a temperature within the range from 240-280 0 O.} The procedure is advantageously carried out as follows *.

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Correspondingly large tablets are produced from copper chromite - produced as described above - or from another catalyst with graphite and the tablets are placed in a reactor which can be heated from the outside. The catalyst is activated in a stream of hydrogen at 100-280 ⁰ C. Then the addition of önantholactam is started. Reaction ratios: 240-280 ⁰ C, molar ratio: lactam / hydrogen 1: 10-1: 50, contact time: 5-25. See, weight rate: 0.1-0.4 g lactam / frin ^ "100 g catalyst. The yield is 50-55%, the selectivity 95-100%. The unreacted lactam can be isolated from the imine by distillation and can be vxm Be hydrogenated again.

In the following, the invention described above is compared mii previous publications known methods:

According to the patent specifications closest to the invention, the heptamethyleneimine is produced from önantholactam by reduction with chemicals with aluminum alkoxide hydrides or with lithium aluminum hydride. Calculated apart from the expensive reducing agents, the best yield of the final product is 73 # and it is nicht'3 ^{rwähnt 'ol} ° ^the remaining 27% unreacted material, regenerated he 1st came in a side reaction or the starting material. In view of the fact that the oenantholactam is not a cheap raw material, the yield based on the starting material has a substantial influence on the economy. The relatively lower yield ⁷ and the expensive reducing agent considered taking seems to be much more expensive than the inventive process the process.

In another process, önantholactam-O-methyl ether is used as the starting material. The önantholactam- -O-methylether is made by the methylation of önantholactam produced and the yield in this reaction with respect to the

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OM ^ thylithers is 87 %. This starting material in itself is more expensive than the önantholactam according to the invention. The O-methyl2 * ether is reduced with the likewise expensive sodium borohydride to heptamethyleneimine with a yield of 68%. According to another publication, the O-methyl ether is produced by catalytic hydrogenation, depending on the catalyst, with a yield of 70-4-9 or 51%.

The bis-önantholactam-ether can also serve as a starting material. The above is also produced from enantholactam with a yield of 77 %, so it is more expensive than the process according to the invention. The heptamethyleneimine is produced therefrom by Raney nickel hydrogenation with a yield of 48%.

The present invention represents a method inject the heptamethyleneimine in liquid or gas phase from the cheapest starting materialέ, starting from Ünantholactam, with cheap copper chromite catalyst and molecular hydrogen is produced by catalytic reduction. It must be emphasized that the selectivity of the catalyst is almost 100% in the reaction in liquid phase and in gas phase, and the unreacted substance can be practically whole be regenerated, that is, the starting material goes into Side reactions not lost. In the liquid phase is the yield over 90%, that is more than the yield according to the publications or according to the patents. In In the gas phase, the yield of one run is 50-5596.

Taking avenue into consideration, that is according to the invention Process cheaper and easier than previously known methods, and the end product can be obtained without impurities and as a catalytic process, the process be considered modern.

The compound prepared according to the invention is a pharmaceutically valuable raw material (USA patents No. 2 928 829 and 3 055 882).

Details of our procedure can be found in the two

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can be found in play.

example 1

200 ml of alcoholic solution (about 20% by weight solution) of 40 g of önantholactam is placed in a tilting autoclave with a volume of 1 liter, and 20 g of copper chromite catalyst in powder form are added. The autoclave is closed, flushed with nitrogen and hydrogen and adjusted to 100 atm with hydrogen. pressed. ^D as Geschüttel is started (1OO tilting / min.), And the autoclave is heated to 200 ⁰ O. The response time is 8 hours. After cooling and opening the autoclave, the reaction mixture is separated from the catalyst by filtration, and such an amount of concentrated hydrochloric acid that the pH should be between 2 and 3 is added. The alcohol is iodistilled (80-90 % of the alcohol can be regenerated). 70 nil of a 40% strength by weight sodium hydroxide solution are added and the heptamethyleneimine is distilled at 20-30 Hgmm. »The yield is 33 g» 93% of the calculated value.

Comment:

a) The speed of the reaction depends on the ratio catalyst: lactam, as in the following

Table says: ''

Lactami catalyst yield after 2 hours

reaction time

. Λ: 0.25 30 %

1: 0.5 50 %

Λ ι 0.75 - 74%

1: 1 75 %

b) Factors influencing selectivity: concentration of the solution (in a more concentrated solution than 25% by weight, the selectivity becomes smaller).

c) The yield that can be achieved over the same time depends on the concentration of the solution, as in the following Table can be found:

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Concentration% yield in 4 hours

(1: 0.5 lactam catalyst) 14.2 .. 69

21.4. 62

29 20

Example 2

In an electrically heatable tubular reactor with an inner diameter of 30 mm, copper or omit granules with a diameter of 2 mm, pelleted with graphite, are placed. 24 g are added, which means a 70 mm high: & catalyst bed. In the upper part of the reactor there is an evaporator or an adjustable liquid and gas feeder is connected to the evaporator. The catalytic reaction begins at a rate of 0.5 l / g catalyst started and the reactor is heated to 100 ⁰ C · It starts _x exceptionally e.xothermische reaction and the temperature of the catalyst bed can sick suddenly 100-200 ⁰ C raise. The heating of the catalyst should continue to be regulated in such a way that the temperature of the catalyst bed never rises above 300.degree. The approximately 100 ⁰ C temperature of the ^H eizung bring the above into consideration taking slow and after completion of the exothermic. Reaction is heated for up to 280 ⁰ C. The temperature is maintained for a further 3 hours. . ■,

After the activation of the catalyst, the lactam vapors begin to be introduced, the temperature of the reactor is 280 ° 0, lactam: hydrogen molar ratio 1:40, weight rate O _t 37 ^ g lactam / minute, 100 g catalyst, contact time 8.6 seconds.

The yield is 50% and the selectivity is 100 %. The reaction mixture can be separated by vacuum distillation, the unchanged lactam can be recovered and hydrogenated again.

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Claims (1)

PATENT CLAIMS A process for the preparation of heptamethyleneimine auich reduction of enantholactam, characterized in that in enantholactam G _e -t _enwar g; _from one ^! Hydrogenated catalyst in liquid or gas phase. 2. The method according to claim 1, characterized g e! '"Indicates that the hydrogenation in the presence is carried out by copper chromite. '3 · Method according to claims 1 to 2, characterized marked * that the hydrogenation in liquid phase at 80-120 atm. and is run at 180-220 ⁰ C throughput \. 4. Process according to claims 1 to 2, characterized in that the hydrogenation is carried out in the gas phase at atmospheric pressure, at 240-280 ⁰ G. 4098U / 1206