DE859612C - Process for the production of ª ‡, ª ‰ -unsaturated carboxylic acids and their derivatives - Google Patents

Description

Process for the preparation of a, f-unsaturated carboxylic acids and their Derivatives It has been found that the preparation of a, unsaturated carboxylic acids and their derivatives by the reaction of acetylene or acetylene series compounds with carbon oxide and compounds with a mobile hydrogen atom, such as water, alcohols, Phenotes, ammonia and derivatives thereof with at least one bound to nitrogen Hydrogen atom, e.g. B. amines, also hydrogen sulfide or mercaptans ,, in The presence of catalysts succeeds particularly smoothly 'if one under- -Addition -of -organic. yerbindüngen with high dielectric constant works. Such Middle- . are for example formamide (e- = IOI-- for 8oo Hz and + 2o °), acetonitrile 75 for 300 Hz and + 20 °) and acetamide (E = 5g = for 8oo Hz and + 20 °), - benzonitrile - (a = 26-, 5 for Soo Hz and + 20 °). Other solvents can also be used be used.

In addition to acetylene, one-sided and two-sided materials are suitable as starting materials substituted acetylenes, e.g. B. methyl, vinyl, isopropenyl or phenylacetylene, Dimethyl-acetyl, en, -. - diacetylene, -. Divinylacetylene, Dipropargyl, Propargyl alcohol or its homologues, and butyn-2-diol-1, 4th and its homologues or aminoalkynes such as 2-dimethylaminobutyne-3.

The reaction proceeds, explained using the example of acetylene and water, according to the following equation: CH- CH + COH; O-CH2 = CH-COOH If alcohols or phenols are used instead of water, esters are obtained; Ammonia and amines give amides, while hydrogen sulphide and captan give thioacrylic acid or its esters.

Monovalent and polyvalent aliphatic, aliphatic-aromatic, hydroaromatic and heterocyclic alcohols and phenols with one or more Oxy groups. Examples are: ethyl alcohol, butyl alcohol, dodecyl alcohol, Benzyl alcohol, cyclohexanol, decahydronaphthole, phenol, p- (tert.) - butylphenol, Pyrocatechol or pyrogallol and naphthols. Suitable derivatives of ammonia, which contain at least one hydrogen atom bonded to nitrogen are, for. B. primary or secondary aliphatic, aliphatic-aromatic, hydroaromatic, aromatic and lieterocyelic mono- and polyvalent amines or bases, e.g. B. dimethylamine, Ethylamine, butylamine, dodecylamine, hexamethylenediamine, cyclohexylamine, ß-imidazolylethylamine, Pyrrolidine, piperidine, melamine, p-, phenylenediamine and also urea. Furthermore can hydrogen sulfide and mono- or fully-finished aliphatic, cycloaliphatic, aromatic-aliphatic, aromatic and also heterocyclic Mercaptans. Examples include: ethyl mercaptan, dodecyl mercaptan, thioglycolic acid, Octodecanedithiol-i2, 18, benzyl mercaptan, thiophenol, p-thiocresol and 2-mercaptobenzothiazole. These starting materials can also be different, reactive with acetylenes at the same time Substituents included. One can also start from mixtures of different substances and then receives mixtures of corresponding conversion products, e.g. B. from alcohol-water mixtures Mixtures of an ester with an acid.

Suitable catalysts are metals and metal compounds that are capable of forming carbonyls, e.g. B. nickel or cobalt, nickel sulfide or halides, or salts of nickel with organic acids, e.g. B. nickel acetate, Nickel propionate, nickel naphthenate or nickel salts of aryloxy fatty acids, as well also the metal carbonyls themselves, e.g. B. 1, nickel carbonyl.

To speed up the implementation you can work together with the above Also add non-carbonyl-forming metals to catalysts. For this are special suitable the metals of the 2nd, 3-, 4- and 5th group of the Periodic Table, e.g. B. Cadmium, Aluminum, scandium, yttrium, cerium or lanthanum, also tin, lead, arsenic and whole especially bismuth and antimony. These metals can e.g. B. in the form of chips or Granules or can be used on carriers. In the latter case you can they either by applying the metal itself, e.g. B. by electrolytic deposition, Cathode sputtering in a vacuum, spraying on, etc., or by reducing the in oxides or sulfides applied to the carrier in a suitable manner can be obtained. The reduction can be carried out with reducing gases, e.g. B. hydrogen or carbon oxide more easily reducible oxides also in the liquid phase, e.g. B. with hydraz: in or Hydroxylamine.

The effectiveness of the catalysts can also be reduced by adding other activators, especially halogen compounds such as alkyl halides, still increase.

The implementation works better in the warm than in the cold. One works therefore expediently at an elevated temperature, generally in a temperature range from -i5o to igo °. Temperatures that are too high are to be avoided, as there is then the risk of Acetylene decomposition and the polymerization of the acrylic compounds formed consists. By adding polymerization-preventing substances, e.g. B. quinones, copper sulfate or the chlorides of arsenic and antimony, one can counteract this danger.

The implementation speed can also be increased by that one under increased pressure, z. B. up to 25 or more at, works. The acetylene or the compounds of the acetylene series such as: the carbon monoxide can also be arbitrary Origin and also with inert substances, e.g. B. with gases such as nitrogen or methane, be diluted.

The reaction can be carried out batchwise, e.g. B. in pressure vessels with a stirrer, or continuously, e.g. B. in Riesel @ vessel, en while guiding the gas in countercurrent or in empty towers by passing the reaction solution with the gas from below above. Unreacted starting materials can be removed after separation of the implementation products in the implementation cycle.

The parts given in the examples below are parts by weight. Example i Through an electrically heated, vertical tube made of stainless steel with a volume of 71, which is connected to The precipitated and formed silica gel of 4 to 7 mm grain size is completely filled, 700 ccm of a solution of 830o parts of butanol, 1000 parts of acetonitrile, 40o parts of n-butyl bromide, 100 parts of nickel carbonyl and zoo parts of water are allowed to trickle every hour. At the same time, 300 liters per hour of a gas mixture consisting of equal parts of the volume of carbon oxide and acetylene are passed through the tube in countercurrent under a total pressure of 30 atm. The reaction mixture leaving the tube is collected in a pressure separator and, after the pressure has been released, worked up by distillation. About 75 to 85% can be distilled from the reaction mixture. After 10 hours of operation, the distillate contains 45 to 50% butyl acrylate in addition to a small amount of acrylic acid with a single throughput. After 3 days the yield with a single throughput is still 49%, even after 18 days the conversion is still unchanged.

Example e With an empty, electrically heated, vertical one Iron pipes with a volume of 3 liters are removed every hour from bottom to top 3oo ccm in example i mentioned solution passed, at the same time 301 of the acetylene-carbon oxide mixture are passed through under 3o at pressure in cocurrent. When processing the Reaction mixture in the manner described in Example i is obtained after 10 hours Operating life of a distillate with 27% butyl acrylate, which is practically free of acrylic acid is. After 24 hours the distillate contains over 42% acrylic acid ester. After 5 days the turnover is still the same.

If, under the same conditions, a solution of ammonia in acetonitrile with carbon monoxide and acetylene in a way, after the waste be distilled acetonitrile, a mixture of acetamide and Acrylsäur, amide. Example 3 In a pressure vessel made of stainless steel, a mixture of 74 parts butanol and 15 parts of benzonitrile with 24 parts of anhydrous nickel bromide is at under a total pressure of 3o and at a temperature of 1 75 to i 8o ° so long with a of equal parts by volume of acetylene and carbon monoxide existing gas mixture treated until nothing more is absorbed (28 hours). By distillation of the reaction mixture, butyl acrylate is obtained in a yield of 33%.

: If you take 24 parts of benzyl cyanide instead of 15 parts of benzonitrile, you get the same yield of butyl acrylate is obtained under the same conditions.

Claims (1)

PATENT CLAIM: Process for the production of a, ff-unsaturated carboxylic acids and their derivatives by reacting acetylene or compounds of the acetylene series with carbon oxide and compounds with a mobile hydrogen atom, such as water, alcohols, phenols, ammonia and its derivatives with at least one hydrogen atom bonded to nitrogen, furthermore Hydrogen sulfide or mercaptans, in the presence of catalysts, characterized in that one works with the addition of organic compounds with a high dielectric constant.