DE1029365B - Process for the production of acrylic acid and its derivatives - Google Patents

Description

GERMAN

It is known that acrylic acid or its derivatives can be prepared by using carbon monoxide Acetylene and water or compounds with reactive hydrogen atoms, e.g. B. alcohols, carboxylic acids, primary or secondary amines, in the presence of carbonyl-forming metals or their compounds, in particular nickel halides, converts in the heat and under pressure.

It is also known that complex compounds of nickel are used as catalysts for this reaction which contain phosphonium, arsonium or stibonium compounds in addition to halogen (cf. German patent 805 641). Furthermore, it is known that such complex nickel compounds can also be used as catalysts to use that contain tertiary amines or ammonium compounds derived therefrom (cf. German patent specification 892 445). Finally, it is also known to convert acetylene, carbon dioxide and Compounds with a mobile hydrogen atom in the presence of complex compounds of nickel salts to be carried out with carboxamides (cf. German Patent 949 654).

The subject of patent 1 009 620 is a process for the production of acrylic acid and its derivatives from acetylene, carbon monoxide and water or compounds with a mobile hydrogen atom in the presence of catalysts at elevated temperature and under pressure, in which complex compounds of halides of carbonyl-forming metals and complex-forming compounds are used as catalysts of the general formula X - CH ₈ - · (CH ₂ ) "- Y, the two elements of V. and or or VI. Main group of the periodic table included. In this formula, X and Y denote an oxy, alkoxy, aryloxy or acyl group or a corresponding sulfur or sulfur-containing group or a radical of a primary or secondary amine or phosphines; however, X and Y are not intended to represent oxy groups at the same time; η has the value 0, 1 or 2.

It has now been found that the preparation of acrylic acid and its derivatives can be carried out particularly advantageously if compounds of the general formula X —CH ₂ - (CH ₂ ) _n - Y, in which X is a nitrile or imino ether, are used in their preparation - Or acid amide group and Y a nitrile, imino ether, acid amide, oxy, alkoxy, aryloxy or acyl group or a corresponding sulfur or sulfur-containing group or the remainder of a primary or secondary amine or phosphine and η the value 0 to 5 has.

The use of these compounds makes it possible to use smaller amounts of complex-forming organic Connections than before. In some cases it is sufficient to use 50% of the theoretical complex formation to use the necessary quantities. This is in many processes for the production of acrylic acid and their derivatives

Addendum to patent 1 009 620

Applicant:

Aniline & Soda Factory in Baden
Aktiengesellschaft, Ludwigshafen / Rhein

Dr. Hans Lautenschlager, Ludwigshafen / Rhine,

and Dr. Herbert Friederich, Worms,

have been named as inventors

The low molecular weight of the compounds which can be used according to the invention is advantageous. Farther allow it, especially in the production of the ethyl acrylate, to achieve higher concentrations of ester in the reaction mixture than before, since less By-products arise.

Suitable compounds of the general formula are, for example, malonic acid dinitrile, succinic acid dinitrile, Adipic dinitrile, / ί-ethoxypropionitrile, / 3-ethylmercaptopropionitrile, Dimethylaminoacetonitrile, 3-formylaminopropionitrile, l-cyanobutanone- (3), succinic acid diamide, Adipic acid diamide, l-cyano-3-methylaminopropanone- (3), Acetylaminoacetonitrile, malonic acid di-Ν, Ν'-methylamide, Thiodipropionitrile or levulinic acid nitrile.

Bidentate complexing agents, such as the compounds described, have a catalytic effect on the compounds the only one active group, e.g. B. an acid amide or nitrile group contain, superior.

They generally form complex compounds of the formula NiX ₂ · 2 X - CH ₂ - (CH ₂ ) "- Y with heavy metal salts, but such complex formation is not a prerequisite for their usability. In general, the heavy metal salts and the complexing agents are added separately to the reaction mixture, and it is expedient to use concentrated aqueous solutions of these.

In general, it applies from 0.05 to 0.3% of the carbonyl-metal and 0.5 to 1 ° / ₀ of the complexing agent, calculated on the weight of the reaction mixture at. Small amounts of water interfere with the production of the

809 509/419

Acrylic acid derivatives do not. So it is possible in the production of Acrylsäureäthylesters to work with 96 ° / _o alcohol.

The reaction conditions when using the new complexing agents correspond to those customary in the manufacture of acrylic acid according to W. Reppe. It is expedient to work at temperatures of 175 to 200 ^° C. and advantageously at elevated pressure. Inert solvents can also be added to the reaction mixture.

The parts given in the examples below are parts by weight.

example 1

_{2.4 parts of the green complex salt NiBr 2} · 2 adipic acid dinitrile are dissolved in 77.6 parts of ethanol in a shaking pressure vessel made of stainless steel. After the air has been displaced from the pressure vessel with nitrogen, the solution is reacted with a mixture of acetylene and carbon oxide in a volume ratio of 1: 1 under 45 atm at 185 ° C. The pressure, which decreases in the course of the reaction, is adjusted to 45 atm every half hour by forcing in an acetylene-carbon oxide gas mixture. After 12 hours, 34 parts of the gas mixture are received in accordance with a pressure of 203 atm. From the reaction mixture obtained by distillation of 103 parts of a 67 ° / ₀ sodium Acrylsäureäthylesters in ethanol and 11 parts of a residue.

If the procedure is as described above, but 1.2 parts of finely powdered nickel bromide and 3 parts of acetonitrile are added as a catalyst, 87 parts of a reaction mixture containing undissolved nickel bromide are obtained after 12 hours. From this mixture 81 parts of a 12 ° / ₀ aqueous ethanol Acrylsäureäthylesters in addition to 6 parts of an oily residue obtained by distillation.

Example 2

1.2 parts of a 50% strength nickel bromide solution in ethanol and 0.6 part of succinic acid dinitrile are added to 78.2 parts of ethanol. By reaction as in Example 1, 106 parts of a reaction mixture from which one by distillation 94 parts of a 54 ⁰ / "strength Acrylsäureäthylesters ethanol in addition to 12 parts of a rear. Status receives.

Example 3

1.2 parts of a 50% strength nickel bromide solution in ethanol and 0.5 part of acetoaminoacetonitrile are added to 78.3 parts of ethanol. After the reaction as in Example 1, 124 parts of reaction mixture from which, by distillation, 113 parts of a 52 ° / _o by weight Acrylsäureäthylesters and 11 parts of a residue.

Example 4

If you work as in Example 3, but with 0.7 parts of acetaminopropiononitrile instead of 0.5 parts Acetoaminoacetonitrile, 106 parts of a 42% ethyl acrylate are obtained in addition to 9 parts of residue.

Example 5

76.4 parts of ethanol are added 2.4 parts of a 50 ° / ₀ sodium Nickelbromidlösung in ethanol and 1.2 parts YS-Äthoxypropionsäurenitril. After the reaction as in Example 1, 98 parts are obtained of a reaction mixture from which one by distillation 89 parts of a ίο 45 ° / ₀ by weight in addition to Acrylsäureäthylesters 9 parts receives a residue.

Example 6

1.2 parts of a 50 ° / ₀ Nickelbromidlösung strength in n-butanol and 0.5 parts of malononitrile are to 78.3 parts of n-butanol was added and reacted as in Example 1 but at 185 ° C just under 28 atm pressure. 102 parts of a reaction mixture are obtained from which, by distillation, 92 parts of a 51% strength butyl acrylate are obtained along with 8.5 parts of a residue.

Example 7

2.4 parts of the complex salt NiBr ₂ · 2 adipic dinitrile are dissolved in 77.6 parts of methanol. After the reaction as in Example 1, 99 parts of a reaction mixture caused, a 37 ° / _o by weight Acrylsäuremethylesters in methanol obtained from the one next to 9 parts of a residue 91 parts by distillation.

Claims (2)

Patent claims: 1. Modification of the process according to patent 1009620 for the preparation of acrylic acid and its derivatives from acetylene, carbon oxide and water or compounds with a mobile hydrogen atom in the presence of catalysts at elevated temperature and under pressure, characterized in that the catalysts are complex compounds of halides of carbonyl-forming metals and complex-forming compounds of the general formula X - CH ₂ - (CH ₂ ) "- Y used, in which X is a nitrile, imino ether or an acid amide group and Y is a nitrile, imino ether, acid amide, oxy, alkoxy, Aryloxy or acyl group or a corresponding sulfur or sulfur-containing group or the radical of a primary or secondary amine or phosphine and η has the value 0 to 5. 2. The method according to claim 1, characterized in that the complex metal compounds by adding the individual components to the starting mixture during the implementation. Publications considered: German Patent Specifications. No. 805 641, 892 445; ^: German Auslegeschrift B 31855 IVb / 12o (published on March 29, 56).