HU185290B - Process for preparing amines - Google Patents

Abstract

FIELD OF THE INVENTION The present invention provides an improved process for the preparation of C2-C22-amines having C2-C22-nitriles, a gas containing at least 50% by volume of hydrogen, preferably hydrogen gas or hydrogen at 50% by volume of synthesis gas and optionally ammonia gas at a pressure of 1 to 150 at 50 and 50. At a temperature of -400 ° C, in the presence of a catalyst obtained by the partial or complete removal of the aluminum content by alkaline dissolution of nickel, aluminum, magnesium and optionally copper and / or iron. The process according to the invention comprises: a) 45-48.1% by weight of nickel, 46-51.0% by weight of aluminum, 0.1-3% by weight of magnesium and 0.1-3% by weight with a fixed bed catalyst system. from copper and / or from 0.1 to 3% by weight of iron, by dissolving a portion of the aluminum content, preferably 50% of the alkali solution, and washed at pH 7.0-10.0, or b) using a suspended catalyst system a catalyst of the initial composition according to variant a) is obtained by dissolving the total amount of aluminum content and washed to pH 7.0-10.0. ^^ Inventory ^ Patent Library. '1 property -1-

Description

The present invention relates to a process for the preparation of C ₂ -C ₂₂ amines by catalytic hydrogenation of nitriles using at least 50% hydrogen gas and ammonia in the presence of a hydrogenation catalyst which provides a very high conversion rate of starting material without side reactions.

Amines are known to be prepared from a wide variety of materials such as alkyl halides, alcohols, carbonyl compounds, and nitrogens. In view of the different nature of the reactions with the various starting materials and the different functions of the catalysts required, the use of different starting materials is an independent part of the state of the art. Therefore, only procedures based on nitriles are discussed below.

It is known to produce amines by catalytic reduction of nitriles, for example in the presence of palladium, platinum, nickel or cobalt hydrogenation catalysts. Hydrogenation is conveniently carried out in an organic solvent at a pressure of 1-200 at and 100-250 ° C (Houben-Weyl, "Methoden der organíschen Chemie", Vol. XI / 1, p. 343, Georg Thieme Verlag, Stuttgart, 1957). .

During the reduction of nitriles, the following reaction equations are expected:

However, it will be appreciated by those skilled in the art that, for industrial scale production, it is important to avoid high imine concentrations and Schiff base formation during the hydrogenation, and to be able to influence I-VI. the reaction steps mentioned in the equations, in particular

III. is a reversible reaction. Therefore, during the hydrogenation of the nitriles, the catalyst used and the activity of the catalyst, in particular the time required for the reaction to complete, have a particular role in the control of the secondary reactions, e.g. The catalyst used is nickel on an alumina support in the presence of an alkali metal hydroxide and an inert organic solvent at a pressure of 50 kg / cm ² of hydrogen gas. According to Example ^D of Examples 11 and 12 of this specification, a conversion rate of 96.9% can be achieved with an alkali metal hydroxide and 85.7% without an alkali metal hydroxide.

No. 55,959. According to the GDR patent, a pre-reduced mixture of Ni (Cu) Mn oxide or carbonate 5 is used, and in the presence of this catalyst, the palmityl stearyl nitrile mixture is hydrogenated at a temperature of 150 to 200 ° C for 21 minutes, with 80% amine. yield.

I

II

III

ARC

V

VI

R-C = N + H ₂ - »R-CHNH (imin)

R-CHNH + CH ₂ NH ₂ (primary amine)

R-CHNH + NH ₂ CH ₂ -R ^ R-CH-NHCH ₂ - ~ R 1 (intermediate)

NH,

NHCH ₂ - R

R ₁ - CH ₂ + H ₂ -> R - CH ₂ NHCH ₂ - R + NH ₃

NH ₂ (secondary amine)

NH ₂

R-CH ^ R-CH == N-CH 1 -R + NH ₃

NHCH, - R (Schiff base)

R-CHNH + R-CH ₃ NHCH 3 -R + H ₂ -R (CH ₃ ) ₃ N + NH ₃ (tertiary amine)

It can thus be seen that during the first 4 steps of the reduction, an imine is formed which is further hydrogenated to a primary amine. However, the primary amine can be reacted again with the imine still present in the system to give an intermediate (equation III) which, upon hydrogenation, forms a secondary amine. In addition, a secondary reaction of the secondary amine and the imine may yield a tertiary amine (Equation VI).

In addition to the above reactions, nitriles are highly prone to hydrolysis in all cases where a hydroxyl group is present in the reaction mixture. (Fodor, "Organic Chemistry," Vol. II, p. 1074). In this case, the nitriles are converted to the acid amides or the carboxylic acids according to the following reaction equation: 6 h ₂ oh ₂ or - c = N -> R - CO - NH ₂ - »

OH OH

-> R-CO-OH + NH ₃ 6

G in DE-1190949 discloses an C _s -C ₂₂ -C nitriles catalytic hydrogenation is carried out at 80-200 ° C for 3.5 to 105 atmosphere pressure, nickel catalyst, platinum and palladium or cobalt oxide tartalma9 Zo catalyst , and continuously circulating some of the primary amine products. In this way, the nitrile load can be adjusted to 0.195-0.833 liters per liter of catalyst per hour of catalyst volume.

⁵ According to the 3,372,195 patent, U.S. ruthenium on carbon in an organic solvent, at pressures of 150 and 5 to 20 mol of ammonia (calculated for the nitrile) used in the conversion of nitriles. Under these conditions, 3-methoxypropylamine is obtained in 86% yield with 1 hour reaction at 125 ° C.

According to U.S. Patent No. 4,003,933, 60% by weight of cobalt is hydrogenated to hydrogenate C--C ₁₀ nit nitriles.

185 290 use a supported catalyst containing a total of 0.2-2% by weight of zirconium and ruthenium. This procedure yields 88% yield (see Example 1 of this description).

According to U.S. Patent 2,287,219, amines containing more than 6 carbon atoms can be prepared from nitriles on Raney nickel catalyst in the presence of water and 0.1 to 0.5% by weight of alkali metal hydroxide. Unreacted nitrile is reported to be present in an amount of 6-9% and the remainder in the range of 15-16%.

According to French Patent 2,063,378, acetonitrile is hydrogenated at a pressure of 30 kg / cm ^{2 in the} presence of Raney nickel catalyst and diethylamine to give monoethylamine in 75-80% yield.

The processes described above can be carried out in batch mode (e.g., rotary autoclaves with agitator) with reaction times of several hours, or some in continuous mode in different types of reactors. In the case of continuous operation, fixed bed reactors can achieve from 0.1 to 0.8 liters per liter of catalyst per hour in combination with the recycled material, while reactors with liquid phase reactors can achieve from 0.1 to 0.8 liters per liter of reactor volume per hour. In conclusion, these processes have the decisive disadvantage that, when implemented, they can work both on low catalyst loads, i.e. low throughput (i.e. low productivity), and on the other hand, in most cases, their conversion or yield is below what is desirable for industrial feasibility.

It is therefore an object of the present invention to provide a process for the production of amines, starting from nitriles, which is highly productive, high-yield, continuously feasible, and controllable to reduce the formation of by-products.

We have realized that this goal can be achieved if

(a) 45 to 48,1% by weight of nickel, 46 to 51,0% by weight of aluminum, 0,1 to 3% by weight of magnesium and, where appropriate, 0,1 to 3% by weight of copper and / or 0,1 to 4% by weight, when a fixed bed catalyst system is used; A catalyst obtained from an alloy containing 3% by weight of iron by dissolving a portion of the aluminum content, preferably 50%, in an alkaline solution and washing it to a pH of 7,0 to 10,0, or

b) using a slurry catalyst system, using a catalyst obtained from the alloy of the initial composition according to variant a) and washing it to pH 7.0-10.0, and in each case using the nitrile or nitrile mixture as starting material, It is passed through the reaction space at a rate of 5-6 liters / liter.

SUMMARY OF THE INVENTION The present invention relates to a process for the preparation of C ₂ -C ₂₂ amines by reacting a C ₂ -C ₂₂ nitrile with a gas containing at least 50% hydrogen, preferably pure hydrogen gas or more than 50% hydrogen in synthesis gas and optionally ammonia gas. -150 at a pressure and 50-100 ° C in the presence of a catalyst obtained by the partial or total removal of the aluminum content from an alloy containing nickel, aluminum magnesium and optionally copper and / or iron. According to the invention, the reaction is carried out as a catalyst for the reaction

(a) 45 to 48,1% by weight of nickel, 46 to 51,0% by weight of aluminum, 0,1 to 3% by weight of magnesium and optionally 0,1 to 3% by weight of copper and / or 0,1 A catalyst obtained from an alloy containing 3% by weight of iron by dissolving a portion of the aluminum content, preferably 50%, in an alkaline solution and washing it to a pH of 7,0 to 10,0, or

(b) using a slurry catalyst system, using a catalyst obtained from the alloy of the initial composition of variant (a) by dissolving the total aluminum content and washing to pH 0.7-10.0, and in each case using the nitrile or nitrile mixture as starting material, It is passed through the reaction space at a rate of 5 to 6 liters per liter.

In the practice of the present invention, the catalyst of variant (a) is prepared using a 3% aqueous sodium hydroxide solution, while in the case of variant (b), a 10% aqueous sodium hydroxide solution is used to completely remove the aluminum content. In the latter case, during the dissolution, the temperature of the alkaline solution is raised to a maximum of 80 ° C in order to accelerate or complete the dissolution. It is noted that the preparation of the catalyst can be carried out as described in our Hungarian Patent Application No. 172,700, which relates to the production of amines from aldehydes and / or amines.

In practicing the method of the invention in the case of C ₂ -C ₅ lower nitriles as starting materials are conveniently fixed bed catalyst system, and C ₅ -C working using a catalyst system is preferably suspended for nitri'ek ₂₂ carbon atoms as starting materials.

The main advantage of the process according to the invention is the high degree of conversion or yield, as well as the high productivity achieved.

The invention is further illustrated by the following embodiments.

Example I

At a temperature of 128 DEG C. and a pressure of 60 atoms, a reactor containing 100 ml of a metal catalyst of the composition described in more detail below is fed with 170 ml of a mixture of 490 g of acetonitrile-water azeotropic and 600 g of liquid ammonia per hour.

The metal catalyst used is prepared from an alloy containing 49.5% aluminum, 48.7% nickel, 1.2% iron, and 0.6% magnesium by allowing the alloy to stand in a 3% aqueous sodium hydroxide solution. The aluminum content after release will be 24.5%. After the dissolution is complete, the alkali is filtered off from the catalyst and washed with distilled water to a surface pH of 9.5. The resulting catalyst is then charged to the reactor followed by ammonia

185 290 in a stream of synthesis gas. The reactants are then introduced at a pressure of 60 at and 128 ° C.

Product mixture exiting the reactor by chromatographic analysis of 52.6% ammonia, 38.6% of monoethyl amine ^5, 0.3% diethylamine and 8.5% water. This means that the acetonitrile was converted with 100% conversion and the yield of monoethylamine

33% stearyl linóiéit- 24%, 12% and 31% myristyl palmityl nitrile consisting of a mixture of tallow fatty acid nitrile was added in l% by weight of catalyst is added to one _5, which was prepared as follows.

The alloy containing 50% aluminum, 48.5% nickel, 0.4% copper, 0.2% iron and 0.9% magnesium was allowed to stand at 50 'C with 10% aqueous sodium hydroxide solution and the aluminum content was saturated. After dissolving 20 µm, the powder catalyst was washed to a surface pH of 7.0-9.5 and stored under water until use.

The nitrile mixture containing the suspended catalyst was fed to the reactor at 100 liters and 180 ° C at a flow rate of 6 liters / liter in the presence of 8 moles of hydrogen gas or equivalent hydrogen gas and 2 moles of ammonia gas based on the average weight of the nitrile mixture.

Megelemezve product mixture leaving the reactor was found after the gaseous com- ₃₀ ponens and separation of the catalyst to a 100% conversion was 98.5% primary amine and 1.5% secondary amine formed.

Example 3 35

The procedure described in Example 2 was followed, except that the nitrile mixture containing the suspended catalyst was fed at a rate of 2 liters / liter per hour into a reactor at 100 and 200 ° C in the presence of 6 moles of hydrogen. Thus, with a conversion of 99.7%, the yield of primary amines is 21.2% and that of secondary amines is 78.5%.

Claims (1)

Process for the preparation of C ₂ -C ₂₂ amines by reaction of C ₂ -C ₂₂ nitriles with a gas containing at least 50% hydrogen, preferably pure hydrogen gas or more than 50% hydrogen in synthesis gas and optionally ammonia gas at a pressure of -400 ° C in the presence of a catalyst obtained by the partial or total removal of the aluminum content from an alloy containing nickel, aluminum, magnesium and optionally copper and / or iron, characterized in that: (a) 45 to 48,1% by weight of nickel, 46 to 51,0% by weight of aluminum, 0,1 to 3% by weight of magnesium and, where appropriate, 0,1 to 3% by weight of copper and / or 0,1 to 4% by weight, when a fixed bed catalyst system is used; A catalyst obtained from an alloy containing 3% by weight of iron by dissolving a portion of the aluminum content, preferably 50%, in an alkaline solution and washing it to a pH of 7,0 to 10,0, or (b) using a slurry catalyst system, using a catalyst obtained from the alloy of the initial composition of variant (a) by dissolving the total aluminum content and washing to pH 7.0-10.0, and in each case using the nitrile or nitrile mixture as starting material, It is passed through the reaction space at a rate of 5-6 L / L.