JP3038752B2 - Method for producing cyclic alkylene imines - Google Patents

Description

The present invention relates to a method for producing cyclic alkylene imines.
More specifically, the present invention relates to a method for producing cyclic alkylene imines by subjecting a cyclic ether and ammonia or a primary amine to a gas phase contact reaction in the presence of a catalyst.

[Prior Art] Conventionally, various methods for producing pyrrolidine by reacting tetrahydrofuran and ammonia in the gas phase in the presence of a catalyst have been proposed as follows.

A method for producing pyrrolidine by reacting tetrahydrofuran and ammonia at 400 ° C. in the presence of an alumina catalyst (Chemical Abstracts, Vol. 32, 548 (1938)).

Tetrahydrofuran and ammonia in the presence of a γ-alumina catalyst at 275 to 375 ° C. while using excess ammonia (NH ₃ / THF = 6 to 20 mol / 1 mol) and circulating high boiling by-products A method of producing pyrrolidine by reacting (US Pat. No. 2,525,584).

A method of producing pyrrolidine by reacting tetrahydrofuran and ammonia with a γ-alumina catalyst treated with boric acid (Japanese Patent Publication No. 43-19940).

Method for producing pyrrolidine by reacting tetrahydrofuran and ammonia in the presence of a zeolite catalyst (Jo
urnal of Catalysis, 35 , 325-329 (1974)).

[Problems to be Solved by the Invention] However, in the above method and the method, the conversion and selectivity of tetrahydrofuran are low, and in the above method, the selectivity is improved as compared with the above and the method.
If the conversion of tetrahydrofuran is not sufficient and the conversion is increased by raising the reaction temperature, the selectivity decreases, and excellent reaction results cannot be obtained for both the conversion and the selectivity. Furthermore, the conversion rate of tetrahydrofuran is not sufficient in the above-mentioned method, and it has not been industrially satisfactory.

Means for Solving the Problems In view of the above-mentioned problems of the prior art, the present inventors have keenly developed a method for producing a cyclic alkyleneimine by industrially advantageously reacting a cyclic ether with ammonia or a primary amine. As a result of repeated studies, by reacting cyclic ether and ammonia or primary amine under a specific pressure using a solid acid catalyst, the reaction activity and selectivity are remarkably improved, and can be sufficiently satisfied industrially. The present invention has been achieved by finding that

That is, the gist of the present invention is to react a cyclic ether with ammonia or a primary amine in the gas phase in the presence of a solid acid catalyst to produce a cyclic alkyleneimine. Under a pressure of 0.5 kg / cm ² G or more at the total pressure of the above.

 Hereinafter, the present invention will be described in detail.

The cyclic ether used as a raw material in the method of the present invention is not particularly limited, but is usually represented by the following general formula: The compound shown by is used. More specifically, propylene oxide, tetramethylene oxide (= tetrahydrofuran), pentamethylene oxide (= tetrahydropyran), cyclohexene oxide, styrene oxide, dioxane, morpholine and the like can be mentioned.

Ammonia or a primary amine is used as the other raw material. As the primary amine, methylamine, ethylamine, propylamine, butylamine and the like, usually,
A lower alkylamine having 1 to 4 carbon atoms is used.

Examples of the solid acid catalyst used in the present invention include zeolite, alumina, silica-alumina, silica-magnesium oxide, silica-zirconium oxide, and the like,
Zeolite, alumina and silica-alumina are particularly preferred. As the zeolite, faujasite-type zeolites and shabasite-type zeolites in which at least a part of their cation sites are ion-exchanged with cations of hydrogen, ammonium or a polyvalent metal are preferably used. X-type zeolites and Y-type zeolites are examples of faujasite-type zeolites. L-type zeolites are examples of the shabasite-type zeolites.

In general, faujasite-type zeolite or L-type zeolite is obtained as a natural product or a synthetic product in a form containing an alkali metal such as sodium or potassium which can be ion-exchanged. Such a faujasite-type zeolite or an L-type zeolite in which the cation site is an alkali metal such as sodium or potassium has low catalytic activity as it is, and therefore, usually at least one of the ions of the alkali metal such as sodium or potassium in the cation site. Parts, preferably 20% or more, more preferably 40% or more,
Particularly preferably, the activity of the catalyst can be improved by ion exchange of 50% or more with hydrogen ions, ammonium ions or polyvalent (usually 2 to 3) metal ions.

As the exchange cation, one or more cations are selected from a hydrogen ion, an ammonium ion, and a polyvalent metal ion (preferably a divalent or trivalent metal ion). The above-mentioned divalent or trivalent metal ion is magnesium,
Examples include cations such as calcium, strontium, barium, zinc, cadmium, lead, manganese, tin, cobalt, nickel, iron, cerium, and lanthanum.

The above-mentioned ion exchange is performed by various known methods.
For example, the above faujasite-type zeolite is immersed in an aqueous solution of a salt (chloride, nitrate, sulfate, organic acid salt, or the like) of the above-mentioned exchange cation and ion-exchanged to achieve a predetermined ion exchange rate. The separation is carried out by thoroughly washing the separated solid ion-exchanged zeolite with water and drying.

In the method of the present invention, the above-mentioned cyclic ether and ammonia or a primary amine are subjected to a pressure of 0.5 kg / cm ² G or more at a total pressure of each partial pressure of the reaction raw material and the reaction product in the presence of the solid acid catalyst. A gas phase contact reaction is performed.

In the above reaction, the reaction temperature is usually 250 to 400 ° C., preferably
In the range of 300 to 380 ° C, the reaction pressure is 0.5 kg / cm ² G or more, preferably 0.5 to 5
0 kg / cm ² G, more preferably 1~20kg / cm ² G, particularly preferably, under the conditions of the range of 2~15kg / cm ² G, is carried out. If the reaction temperature is too low, the reaction rate decreases, and if it is too high, side reactions increase, which is not desirable. On the other hand, if the reaction pressure is lower than the lower limit, the activity (reaction rate) and selectivity are remarkably reduced, which is not preferable. The molar ratio of ammonia or primary amine / cyclic ether is usually in the range of 1 to 50, preferably 2 to 30, and more preferably 5 to 20.
In carrying out the process of the present invention, the reaction is carried out in the form of a general gas phase catalytic reaction, and may be a fixed bed type or a fluidized bed type. The space velocity (total gas amount of cyclic ether and ammonia or primary amine (/ hr) / catalyst ()) under standard conditions can be varied over a wide range depending on conditions such as the reaction temperature and the molar ratio of ammonia or primary amine / cyclic ether. But usually 50 to 4,000 hr ^{-1 and} preferably 100 to
Space velocities in the range of 3,000 hr ^-1 are preferably employed. If the space velocity is too low, side reactions increase, and if it is too high, the amount of unreacted substances recovered is undesirably increased.

The cyclic alkylene imines obtained by the above reaction are a medicine,
Compounds useful as synthetic intermediates such as insecticides and rubber accelerators.

The present invention is particularly suitably used for producing pyrrolidine or N-alkylpyrrolidine from tetrahydrofuran and ammonia or a primary amine.

[Examples] Next, the embodiments of the present invention will be described more specifically with reference to the following Examples.
It is not limited by the following examples.

The zeolite catalysts used in the following Examples and Comparative Examples were prepared or pretreated by the following methods, respectively.

(A) Catalyst /: H-X zeolite Na-X zeolite (Molecular manufactured by Union Showa Co., Ltd.)
Sieve Type 13X; Na ₈₆ [(AlO ₂ ) ₈₆ (SiO ₂ ) ₁₀₆ ] xH ₂ O)
Was ion-exchanged to obtain NH ₄ -X zeolite, and then pre-calcination treatment was performed to obtain H-X zeolite.

That is, 30 g of the above-mentioned Na-X zeolite was added to an aqueous solution obtained by dissolving 51.5 g of NH ₄ Cl in 300 ml of water, and ion-exchanged by stirring at 70 ° C. for 2 hours. After repeating this ion exchange operation three times, it was washed with demineralized water at room temperature, passed, and then dried at 100 ° C. for 12 hours to obtain NH ₄ —X zeolite. This was molded into particles having a diameter of 1-2 mm. And
H-X zeolite was calcined in air at 400 ° C for 1 hour and further in nitrogen at 400 ° C for 1 hour.

(B) Catalyst 2: HL zeolite KL zeolite (Molecula, manufactured by Union Showa KK)
r Sieve SK-45) and by ion-exchange and NH ₄ -L zeolite, then the H-L zeolite was calcined pretreated.

(C) Catalyst 3: Alumina Commercially available alumina catalyst (SCM-2 manufactured by Rhone Poulin Co.)
50) was molded into particles of 1-2 mm diameter. And it pre-processed by baking in air at 400 degreeC for 1 hour, and also in nitrogen at 400 degreeC for 1 hour.

(D) Catalyst 4: Silica-alumina Commercially available silica-alumina catalyst (N-63, manufactured by JGC Corporation)
1HN) into particles of 1-2 mm diameter. And it pre-processed by baking at 400 degreeC for 1 hour in nitrogen at 400 degreeC further in nitrogen.

Examples 1 to 13 An upper part of a SUS-316 reaction tube (inner diameter 25 mmφ, length 480 mm) was filled with 90 cc of glass beads as a cyclic evaporator for evaporating cyclic ether and ammonia, and the lower part was a reaction zone shown in Table 1 as a reaction zone. And amount of catalyst. The reaction tube was heated from the outside by an annular electric furnace to heat the pre-evaporation zone and the reaction zone, respectively, and adjusted so as to maintain a predetermined temperature.

Next, tetrahydrofuran (THF) and ammonia were supplied to the reaction zone in the amounts shown in Table 1 to adjust to the ratio shown in Table 1, and the reaction was carried out under the reaction conditions shown in Table 1. It was condensed and collected in a trap cooled with glycol-water refrigerant. The obtained liquid reaction product was analyzed by gas chromatography. Uncondensed gas components were collected in a gaseous state and analyzed by gas chromatography. Table 1 shows the results.

Comparative Examples 1 to 4 The same operation was performed as in Examples 1 to 10, except that the reaction pressure was changed to normal pressure (atmospheric pressure). Table 1 shows the results.

[Effect of the Invention] According to the method of the present invention, cyclic alkylene imines can be produced from a cyclic ether and ammonia or a primary amine at a high conversion and a high selectivity.

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C07B 61/00 300 C07B 61/00 300 (72) Inventor Fumio Morita 3-10, Shiodori, Kurashiki-shi, Okayama Pref. (72) Inventor Kazuaki Miyaji 3-10 Ushidori, Kurashiki-shi, Okayama Pref. Mizushima Plant, Mitsubishi Kasei Co., Ltd. (56) References Journal of Catalysis, Vol. 41, p. 322-328 (1976) Journal of Catalysis, Vol. 351, p. 325-329 (1974) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07D 295/00-295/22 C07B 61/00 300 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (6)

(57) [Claims] In producing a cyclic alkyleneimine by reacting a cyclic ether with ammonia or a primary amine in the gas phase in the presence of a solid acid catalyst, the reaction is carried out by summing the partial pressures of a reaction raw material and a reaction product. A process for producing cyclic alkylene imines, wherein the process is performed under a pressure of 0.5 kg / cm ² G or more. 2. The method according to claim 1, wherein the total pressure of the partial pressures of the reaction raw material and the reaction product is in the range of 0.5 to 50 kg / cm ² G. 3. The method according to claim 1, wherein the total pressure of each partial pressure of the reaction raw material and the reaction product is in the range of ² to 15 kg / cm ² G. 4. The process according to claim 1, wherein the molar ratio of ammonia or primary amine / cyclic ether ranges from 1 to 50. 5. The method according to claim 1, wherein the reaction temperature ranges from 250 to 400 ° C. 6. The process according to claim 1, wherein the solid acid catalyst is a catalyst containing at least one selected from zeolite, alumina and silica-alumina.