JP2720504B2 - Method for producing N-alkylated cyclic alkylenimine - Google Patents

Description

The present invention relates to a method for producing an N-alkylated cyclic alkylene imine. More specifically, the present invention relates to a method for producing an N-alkylated cyclic alkyleneimine by subjecting a cyclic alkyleneimine to an alkylation reaction with an alcohol or an ether in the presence of a catalyst.

N-alkylated cyclic alkylene imines are useful compounds as synthetic intermediates such as pharmaceuticals, insecticides, and rubber accelerators.

[Conventional technology]

Conventionally, various methods for N-alkylating a cyclic alkyleneimine have been proposed, and for example, the following methods are known.

Using a catalyst consisting of nickel or cobalt, copper and titanium dioxide, morpholine and alcohol
The reaction is carried out at a temperature of 〜300 ° C. and a pressure of 35 to 350 atm (see Belgian patent 694068).

Method of alkylating piperazine and alcohol at a temperature of 200 ° C using Raney nickel catalyst (JO
rg. Chem., 21 , 86-87 (1956)).

A method for producing an N-alkylpiperidine by reacting piperidine with an alcohol in the presence of an aluminum oxide catalyst (Coll. Of Czechoslovak Chemical Communicat)
ions, Vol. 33, No. 2, 609-613 (1968)).

A method in which a cyclic alkylene imine such as morpholine, piperidine, piperazine and the like is alkylated with an alcohol in the presence of a phosphoric acid-containing silicon dioxide catalyst (see JP-A-48-86857).

[Problems to be solved by the invention]

However, in each of the above-mentioned methods, the activity and selectivity of the catalyst were low and were not industrially satisfactory.

[Means for solving the problem]

In view of the above problems of the prior art, the present inventors have made intensive studies on a method for producing an N-alkylated cyclic alkyleneimine in an industrially advantageous manner by alkylating a cyclic alkyleneimine with an alcohol or ether. As a result, it has been found that by reacting a cyclic alkyleneimine with an alcohol or an ether using a specific zeolite catalyst, the activity and selectivity of the catalyst are remarkably improved, and the catalyst is industrially sufficiently satisfactory. Reached.

That is, the gist of the present invention is that when a cyclic alkylene imine and an alcohol or an ether are subjected to an alkylation reaction in the presence of a catalyst, at least a part of the cation site as a catalyst is a hydrogen ion, an ammonium ion or a polyvalent metal cation. Using an exchanged faujasite-type zeolite, and a method for producing an N-alkylated cyclic alkyleneimine, characterized by reacting in the gas phase,
Exists.

 Hereinafter, the present invention will be described in detail.

The cyclic alkyleneimine 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, for example, propylene imine, pyrrolidine, piperidine, piperazine, morpholine, hexamethylene imine and the like can be mentioned.

Examples of the alcohol used as the other raw material include aliphatic alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, and hexyl alcohol; alicyclic alcohols such as cyclopentanol and cyclohexanol; And aromatic alcohols such as alcohols. Particularly, aliphatic alcohols having 10 or less carbon atoms are preferred.

Further, examples of the ether include ethers corresponding to the above aliphatic alcohols, for example, methyl ether, ethyl ether, propyl ether, isopropyl ether, butyl ether, hexyl ether and the like.

In the method of the present invention, a faujasite-type zeolite in which at least a part of its cation sites are ion-exchanged with hydrogen ions, ammonium ions or polyvalent, for example, divalent or trivalent metal cations is used as a catalyst. Examples of the faujasite-type zeolite include an X-type zeolite and a Y-type zeolite.

In general, faujasite-type zeolites are obtained in both natural products and synthetic products in a form containing an alkali metal such as ion-exchangeable sodium. For example, X-type zeolite whose sodium cation site is sodium is represented by oxide (1 ± 0.2) Na ₂ O.Al ₂ O _3. (2.5 ± 0.5) SiO ₂ .yH ₂ O [where y is 0 to 8] Represents any number of And Y-type zeolite is similarly (1 ± 0.2) Na ₂ O.Al ₂ O _3. (4.5 ± 0.5) SiO ₂ .yH ₂ O [where y is an arbitrary number from 0 to 9] Represents ] Is represented.

Since the faujasite-type zeolite in which the above-mentioned cation site is an alkali metal such as sodium has low activity of the catalyst as it is, in the present invention, at least a part of the alkali metal ion such as sodium ion of the cation site, preferably 20 % Or more, more preferably 40%
The catalyst is made highly active by ion-exchanging at least 50%, most preferably at least 50%, with hydrogen ions, ammonium ions or polyvalent (usually 2 to 3) metal cations.

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-described ion exchange can employ various known methods. For example, the above-mentioned faujasite-type zeolite is immersed in an aqueous solution of salts of exchange cations (chloride, nitrate, sulfate, organic acid salt, etc.) and ion-exchanged, and after achieving a predetermined ion exchange rate, solid-liquid separation The ion-exchanged zeolite, which is the separated solid component, is thoroughly washed with water and dried.

In the method of the present invention, the above-mentioned cyclic alkyleneimine is brought into contact with the alcohol or ether in the gas phase in the presence of the above-mentioned zeolite catalyst to carry out the alkylation reaction.

The above-mentioned alkylation reaction is carried out under a reaction temperature of usually 200 to 400 ° C., preferably 250 to 350 ° C., and a reaction pressure of normal pressure to pressure, usually 0.1 to 10 atm (gauge pressure). When the reaction temperature is lower than 200 ° C., the reaction rate decreases, and when the reaction temperature exceeds 400 ° C., side reactions increase. The alcohol / cyclic alkylene imine molar ratio is usually in the range of 1 to 10, preferably 1.5 to 5. In the case of ether, the amount is half that of alcohol. The reaction can be carried out in the form of an ordinary gas phase catalytic reaction, and may be a fixed bed reaction or a fluidized bed reaction. The space velocity (total gas amount of cyclic alkylene imine and alcohol or ether (/ hr) / catalyst () in the standard state) can be varied over a wide range depending on conditions such as the reaction temperature and the molar ratio of alcohol / cyclic alkylene imine. But usually 50
~4,000hr ^-1, preferably a space velocity in the range of 100～3,000Hr ^-1 is employed. When the space velocity is less than 50 hr ^-1 , side reactions increase, and when the space velocity exceeds 4,000 hr ^-1 , the amount of unreacted substances recovered increases.

The produced N-alkylated cyclic alkyleneimine can be recovered and purified by a known method such as distillation.

〔Example〕

Next, the embodiments of the present invention will be described more specifically with reference to Examples, but the present invention does not depart from the gist thereof.
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.

(1) Catalyst 1: H-X zeolite Na-X zeolite (Molecula, manufactured by Union Showa KK)
r Sieve Type13X; Na ₈₆ [(AlO ₂ ) ₈₆ (SiO ₂ ) ₁₀₆ xH
₂ O) was used as a NH ₄ -X zeolite by ion exchange, then the H-X zeolite was calcined pretreated.

That is, 30 g of the above Na-X zeolite was put into an aqueous solution obtained by dissolving 51.5 g of NH ₂ Cl in 300 ml of water, and the mixture was stirred at 70 ° C. for 2 hours to perform ion exchange. 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.

(2) Catalyst 2: H—Y zeolite NH ₄ —Y zeolite (Molecul, manufactured by Union Showa KK)
ar Sieve LZ-Y62) was molded and calcined to obtain a HY zeolite in the same manner as the NH ₄ -X zeolite in (1) above.

(3) Catalyst 3: Na-Y zeolite Na-Y zeolite (Molecula, manufactured by Union Showa KK)
r Sieve LZ-Y52) is formed into particles having a diameter of 1 to 2 mm, and is heated in air at 400 ° C. for 1 hour, and further in nitrogen at 400 ° C. for 1 hour.
It was used after firing.

(4) Catalyst 4: H-mordenite H-mordenite (Norton, USA, Ze
olon 100H) was molded and fired in the same manner as in (3) above.

(5) Catalyst 5: HZ 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.

That is, the NH ₄ Cl25.6g in an aqueous solution obtained by dissolving in water 300 ml, the K-L zeolite was 30g turned hereinafter, using the same method as above (1), first NH ₄ -L zeolite And then HL zeolite.

Example-1 20cc of glass beads were filled in the upper part of a quartz reaction tube (inner diameter 15mmφ, length 400mm) as a pre-evaporation of cyclic alkyleneimine and alcohol, and the type and amount shown in Table 1 as a reaction zone in the lower part. Was charged. 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.

Pyrrolidine and methanol were reacted under the reaction conditions shown in Table 1, using a faujasite-type zeolite whose cation site was replaced by a hydrogen ion as a catalyst. The gaseous reaction product containing N-methylpyrrolidine obtained by the reaction was completely condensed and collected by a trap cooled in a dry ice-methanol bath. The obtained liquid reaction product was analyzed by gas chromatography. The results are shown in Table 1.

Comparative Example-1 The operation was performed in the same manner as in Example-1, except that the types and amounts of catalysts shown in Table-2 were used. Table 2 shows the results.

Example 2 The same operation as in Example 1 was performed except that alcohols of the type shown in Table 3 were used and some of the reaction conditions were changed as shown in Table 3. The results are shown in Table-3.

[Effects of the Invention] According to the method of the present invention, an N-alkylated cyclic alkylene imine can be produced from a cyclic alkylene imine and an alcohol or ether at a high conversion and a high selectivity.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C07B 61/00 300 C07B 61/00 300

Claims (1)

(57) [Claims] (1) In performing an alkylation reaction between a cyclic alkylene imine and an alcohol or ether in the presence of a catalyst, at least a part of the cation site is ion-exchanged with a hydrogen ion, an ammonium ion or a polyvalent metal cation as a catalyst. A method for producing an N-alkylated cyclic alkyleneimine, comprising using a faujasite-type zeolite and reacting in the gas phase.