DE1014097B - Process for the production of adipic diamide - Google Patents

Description

GERMAN

It is known to produce adipic acid diamide by heating adipic acid or adipic acid ammonium in the Produce ammonia red to temperatures of around 170 °. That obtained in a maximum of 75% yield Diamide is brown and must be recrystallized from water before it can be processed further can.

In order to increase the yields, the heating to about 170 ° has only been carried out until the amide began to precipitate from the melt. This was then separated off and the unchanged adipic acid ammonium was put together with fresh adipic acid continues with ammonia. Repeating this several times resulted in higher ones Yields than in the former process.

It has now been found that pure adipic acid diamide can be obtained in a virtually quantitative yield on a simpler one Way is obtained when in a first stage in the melt of the adipic acid within a temperature range between the melting point and about 180 ° gaseous ammonia is introduced for as long as until the ammonium salt of adipic acid has formed almost completely and then in a second Stage the reaction mixture at slowly increasing to a maximum of about 230 °. Temperature with ammonia treated. A separation of amide in an intermediate stage and a repeated treatment with Ammonia, as is necessary in the known case, is not necessary.

In the first stage of the process, which leads to the formation of the ammonium salt, most of the Ammonia initiated. In the second stage, the addition of ammonia is throttled so far that its Amount sufficient to prevent a retrograde reaction.

The process can also be carried out in the presence of an inert solvent. Used if about 10 to 20% of this, based on adipic acid, then its melting point is lowered, and the The ability to stir the melt is improved. As solvents are, for. B. suitable: tetrahydronaphthalene, Trichlorobenzene or dichlorobenzene.

In the first heating stage, the temperature is in the specified temperature range above the Melting point of adipic acid or its mixture is maintained with a solvent. In the second Heating stage lets the temperature within several, z. B. 2 to 4 hours by at least 10 °, advantageously at least 20 °, up to a maximum of about 230 °; it is expedient to stay below the melting point of diet.

The diamide produced according to the invention in almost quantitative yield is colorless and can be used, among other things, for the production process without further purification
of adipic acid diamide

Applicant:

Badisctie Aniline & Soda Factory
Aktiengesellschaft, Ludwigshafen / Rhein

Dr. Karl Merkel and Dr. Albert Palm,

Ludwigshafen / Rhine,
have been named as inventors

ao position of textile auxiliaries, ζ. B. for the production of anti-crease dimethylol compounds be used.

The in the following. The parts mentioned in the examples are parts by weight.

example 1

1460 parts of adipic acid are melted in a stirred vessel at 152 °. With gradual increase the temperature to 170 °, a steady stream of ammonia is introduced over the course of 3 hours. When the formation of the ammonium salt is complete, the ammonia supply is throttled and the temperature is increased to 225 ° in a further 4 hours, with ammonia water being distilled off.

The resulting diamide is in a nitrogen atmosphere drained into a container. It solidifies into a solid block that is broken and too pure white Crystal powder is ground.

The reaction consumes 440 parts of gaseous ammonia, 450 parts of ammonia water (20%) distill off. 1420 parts of colorless adipic acid diamide are obtained.

Example 2

1460 parts of adipic acid are mixed with 120 parts of trichlorobenzene mixed, placed in a stirred vessel and heated to 146 °. You lead into the melt Ammonia for 2 hours, the temperature increasing steadily up to 170 °. Then you throttle. the Stream of gaseous ammonia strongly decreases and increases the temperature in the course of 3 hours 210 °. In the process, ammonia water and trichlorobenzene distill off. The trichlorobenzene can be added to the reaction vessel be fed back.

709 658/413

The reaction mixture is freed from the remaining solvent by distillation in vacuo. the Melt is drained into a container in a nitrogen atmosphere and worked up further as in Example 1. 1430 parts of colorless adipic acid diamide are obtained.

Claims (3)

PATENT CLAIMS: 1. Process for the preparation of adipic acid diamide by reacting adipic acid with Ammonia at an elevated temperature, characterized in that the molten adipic acid in a first stage within the temperature range between the melting point and 180 ° gaseous ammonia is introduced until the ammonium salt is almost completely removed the adipic acid has formed, and that the reaction mixture is then added in a second stage treated slowly with ammonia up to a temperature of at most about 230 °. 2. The method according to claim 1, characterized in that the reaction in the presence of a inert solvent is carried out. 3. The method according to claim 1 and 2, characterized in that in the second stage only so far ammonia is supplied that a reverse reaction is prevented. © 709 658/413 8.57