DE1044097B - Process for the preparation of ring-alkylated aromatic amines - Google Patents

Description

GERMAN

The subject of patent 951 501 is a process for the preparation of ring-alkylated aromatic compounds Amines, which is characterized in that one olefins in the presence of aluminum or its Alloys can act on aromatic amines and the reaction at elevated temperatures, preferably around 200 to 350 ° C, and elevated pressures, preferably around 100 to 200 at, carries out.

In further processing of the inventive idea underlying the process of the main patent it has now been found that even better results are obtained when the results described in the main patent are used Implementation in the presence of iodine or iodine compounds as an additional activator performs. Iodine compounds suitable for the process according to the invention are those in which the Iodine is not bound in an extremely heteropolar manner, such as in the alkali and earth potassium iodides.

The iodine compounds with the elements of III. to VIII. Group of the Periodic Table of the Elements, in particular the metal compounds such as NiI ₂ , CoI ₂ , AlI ₃ , PbI ₂ and preferably the iodides of the metals from Group VIII. However, elemental iodine and its non-metal compounds, such as phosphorus triiodide, can also be used. In general, it has proven to be expedient to add about 0.5 to 1% (based on the amine to be alkylated) of the iodine or the iodine compounds to the reaction mixture. However, larger or smaller amounts can be used.

The olefins suitable for the process are mainly those used in modern cracking processes occurring gaseous olefins such as ethylene, propylene, butylene, isobutylene. The procedure is however not limited to this.

The new method can be carried out in the same way as the method of the main patent be e.g. B. by the aromatic amine with about 2% of its weight in aluminum and with About 0.5 to 1% of its weight is added to anhydrous nickel iodide, and the mixture is heated to 280 ° C and ethylene up to a pressure of 200 atmospheres. The uptake of ethylene takes place very quickly and comes depending on the type of amine used, after taking up 1 or 2 moles of olefin per mole of amine to a standstill.

In principle, the process according to the invention produces the same products as those produced by the process of the main patent can be obtained. However, the reaction proceeds when the mixed catalysts are used more uniform, so that, for example, 2,6-diethylaniline from aniline and ethylene is practically quantitative arises. The most favorable reaction temperature

for the production of nucleus alkylated
aromatic amines

Addition to patent 951 501

Applicant:

Paint factories Bayer Aktiengesellschaft, Leverkus en-B ay erwerk

Dr. Rudolf Stroh, Dr. Josef Ebersberger,
Dr. Hans Haberland, Leverkusen,

and Dr. Willi Hahn, Cologne-Stammheim,
have been named as inventors

The temperature for the new process is on average around 50 ° C lower than for the process of the Main patent.

The batches are worked up by fractional distillation of the reaction mixture. Possibly this is beforehand by stirring with sodium hydroxide solution from the aluminum-amine compound formed freed. The iodine contained in the catalyst can be obtained from the distillation residues according to the recover the usual oxidation methods.

The o-substituted aromatic amines which are easily accessible by the new process are valuable Intermediate products for the production of dyes, pharmaceuticals, pesticides, Plastics, rubber additives, inhibitors and other additives for mineral oils, fuels and the like

example 1

300 g of aniline, 6 g of aluminum powder and 2 g of anhydrous nickel iodide are placed in an autoclave Heated to 280 ° C and treated with ethylene under 200 atmospheric pressure. The ethylene uptake takes place very quickly and is finished after 3V2 to 5 hours. Total will be 185 g of ethylene added, which corresponds to around 2 moles of ethylene per 1 mole of aniline. The distillation of the reaction product does not provide unchanged aniline. The distillate consists of pure 2,6-diethylaniline. The yield is 96% of theory. The 2,6-diethylaniline boils below 10 torr at 110 to 111 ° C.

80S 679- / 412

As a comparison with example 7 of German patent specification 951 501 shows, the reaction product obtained is much more uniform due to the addition of iodide.

Example 2

300 g of aniline, 6 g of aluminum powder and 2 g of anhydrous cobalt iodide are made according to the method of Example 1 reacted with ethylene at 280 ° C. The uptake of ethylene goes at about the same rate before itself as in Example 1 and comes after taking up about 2 moles of ethylene per mole of amine to a standstill. About 2 to 3% of the reaction product are hydrocarbons, the remainder is 2,6-diethylaniline.

Example 3

300 g of aniline, 6 g of aluminum powder and 2 g of anhydrous aluminum iodide are made according to the procedure of Example 1 reacted with ethylene at 280 ° C. The uptake of ethylene (180 g) has ended after 5 hours. When the reaction product is distilled, the 2,6-diethylaniline is in a yield of 94% Theory received.

Example 4

300 g of aniline, 6 g of aluminum powder and 3 g of lead iodide are reacted according to the procedure of Example 1. The uptake of ethylene is somewhat slower than when using nickel] odide. Next to a little 2-ethylamline becomes 2,6-diethylaniline in 88% strength Yield obtained.

treated under 200 atmospheric pressure. 155 g of ethylene are consumed over the course of 6 hours, which corresponds to an uptake of 2 moles of olefin per mole of amine. In the distillation of the reaction mixture = _lo is the 4-methyl-2,6-diethylaniline, bp. 122 ° C obtained in 121 a bis yield of 90 ° / "of the theoretical.

Example 7

ίο 300 g of aniline, 6 g of aluminum powder and 2 g of iodine are reacted according to the method of Example 1 at 280 to 300 ° C with propylene at a pressure of 200 atmospheres. 65 to 70 g of olefin are taken up in the course of 6 hours. To destroy the aluminum anilide, the reaction product is shaken out with dilute sodium hydroxide solution and fractionated in vacuo. 60% * of the product is unchanged aniline, 38% 2-isopropylaniline with a boiling point of ₁₀ = 96 ° C, 2,6-diisopropylaniline is only contained in an amount of about 1%.

Example 8

300 g of aniline, 6 g of aluminum powder, 3 g of phosphorus triiodide and 0.2 g of sublimate are made according to the procedure of Example 1 reacted at 280 ° C with ethylene at a pressure of 200 atü. After about The reaction has ended in 4 hours. During this time a total of 180 g of ethylene are consumed. That with reaction product extracted from dilute sodium hydroxide solution consists practically only of 2,6-diethylaniline, which is obtained in the distillation in a yield of 92% of theory.

Example 5

300 g of aniline, 6 g of aluminum powder and 2 g of iodine are mixed according to the procedure of Example 1 with ethylene implemented. The uptake of ethylene (2 moles per mole of aniline) ends after about 6 hours. In the Distillation of the reaction product gives about 2% 2-ethylaniline, the remainder being 2,6-diethylaniline.

Example 6

300 g of p-toluidine, 6 g of aluminum powder and 2 g of anhydrous Nickel iodide are mixed with ethylene at 300 ° C

Claims (1)

PATENT CLAIM: Further development of the process for the preparation of ring-alkylated aromatic amines from Olefins and aromatic amines in the presence of aluminum or its alloys according to Patent 951 501, characterized in that the reaction is carried out in the presence of iodine or iodine compounds in which the iodine is not extremely heteropolar. I 809 579/412 11:58.