JPH0118072B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improved method for producing piperazine and piperazine derivatives by catalytically reacting diethanolamines with ammonia or primary amines in a liquid phase. More specifically, using a heteropolyacid compound as a catalyst, diethanolamines and ammonia or primary amines are reacted at a temperature of 250°C or higher and under sufficient pressure to maintain the reaction system in a liquid phase to produce piperazine and piperazine. The present invention relates to a method for producing derivatives with good yield. Piperazine and its derivatives are useful chemical products that have a wide range of applications such as pharmaceutical raw materials or their intermediates, food additives, and surfactants. As a method for producing piperazines, a method using liquid phase ammonorinsing of diethanolamines is already known. For example, in JP-A-51-149290, a phosphorus compound such as a phosphate is used as a catalyst, and N
The preparation of corresponding N-(substituted) piperazine and NN'-(disubstituted) piperazine compounds directly from a -(substituted) dialkanolamine and ammonia or a primary amine is disclosed. US Pat. No. 2,636,033 discloses the production of NN'-bis(2-hydroxyethyl)piperazine by dehydration condensation of 2 moles of diethanolamine using a specific inorganic acid such as phosphoric acid or phosphate as a catalyst. has been done. Additionally, U.S. Patent No.
As seen in No. 2910477, there is also a method of producing a piperazine compound by reacting diethanolamine and ammonia under conditions of high temperature and pressure using Raney nickel as a catalyst. None of these methods have sufficient catalytic activity, and problems still remain in their industrial implementation. Taking these circumstances into consideration, the present inventors have conducted extensive research in order to effectively react diethanolamines with ammonia or primary amines to obtain piperazine and its derivatives in good yield. As a result, the heteropolyacid compound becomes an excellent catalyst for this reaction. In other words, when the reaction between diethanolamines and ammonia or primary amines is carried out catalytically in the liquid phase, the heteropolyacid compound has extremely high activity. They discovered that piperazine and its derivatives could be produced in high yields, and upon further investigation, they found that the catalyst activity remained stable and could be used repeatedly.
The present invention was achieved by discovering that the present invention can be implemented satisfactorily industrially. A feature of the process of the invention is that) with known catalysts:
Long reaction times were required to obtain sufficient activity, but heteropolyacid compounds show higher activity than any catalyst proposed so far, and exhibit extremely high performance, especially when used in liquid phase systems. Therefore, the desired yield can be achieved in a relatively short time and it can be carried out advantageously.
Excellent thermal stability even at high temperatures above ℃,
(a) The selectivity of piperazine and its derivatives is extremely high.) Corrosion of the material by heteropolyacids is hardly a problem, and only corrosion by ammonia should be considered. Therefore, ordinary general-purpose stainless steel can be used as the device material, which is very advantageous industrially. The diethanolamines used in the method of the present invention have the general formula () (Here, R ¹ represents hydrogen, a substituted or unsubstituted alkyl group, or an aryl group.) Specifically, diethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-( 2-
(aminoethyl)diethanolamine, N-phenyldiethanolamine, and the like. In ^{addition ,} primary amines are _ammonia or primary It is an amine. Specifically, ammonia (liquid ammonia, gaseous ammonia, aqueous ammonia at any concentration), methylamine, ethylamine, propylamine, ethylenediamine, ethanolamine, aniline, P-aminophenol, propanediamine, etc. . Diethanolamines and ammonia or
In order to obtain the desired piperazine and its derivatives in good yield, it is preferable to use an excess amount of ammonia, but in the method of the present invention, the amount of ammonia or Preferably, the primary amines are in the range of 2 to 20 moles. If the amount of ammonia is too low than this range, morpholine etc. will be produced, and if it is too much, the production of chain amines such as diethylenetriamine will be noticeable and the selectivity of piperazine and its derivatives will be reduced. A particularly preferred range is a molar ratio of 1:3 to 1:10. The heteropolyacid compound used in the method of the present invention is a heteropolyacid that contains at least one metal atom of tungsten, molybdenum, and vanadium, is stable at temperatures of 250°C or higher, and is a heteropolyacid that is a member of the first group of the periodic table. or an ammonium salt of the heteropolyacid. Specifically, phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, germanotungstic acid, borotungstic acid, cobalt tungstic acid, phosphomolybdotungstic acid, phosphovanadotungstic acid, and these heteropolyacids. respectively sodium salt, potassium salt, lithium salt, copper salt, silver salt, magnesium salt,
Examples include calcium salts, zinc salts, iron salts, cobalt salts, nickel salts, and ammonium salts. Among these, phosphomolybdic acid, silicotungstic acid, phosphotungstic acid, borotungstic acid,
Sodium silicotungstate, potassium silicotungstate, sodium phosphotungstate,
Particularly preferred are potassium phosphotungstate, copper phosphotungstate, copper phosphotungstate, cobalt phosphotungstate, nickel phosphotungstate, ammonium phosphotungstate, ammonium phosphotungstate, phosphovanadotungstate, and zinc phosphotungstate. The amount of such a catalyst to be used may be small since the heteropolyacid compound has extremely high activity, but the appropriate amount depends on the reaction temperature and may be adjusted depending on the temperature at which the reaction is carried out. Generally, a range of 0.1 to 10.0 mol% is suitable for diethanolamines,
If the amount is less than this range, the reaction rate will be extremely low, and if it is more, the catalyst cost will be high and it will be economically disadvantageous. Within this range, 0.5 to 5.0 mol% is particularly preferred. The reaction temperature when carrying out the method of the present invention is 250
℃ or higher is required, but a range of 250 to 350°C is appropriate. If the temperature is lower than this range, the reaction rate becomes extremely slow and is not practical. On the other hand, if the temperature is higher than this range, side reactions such as decomposition reactions and polymerization reactions of diethanolamine and reaction products become significant, and it is no longer possible to obtain the reaction. It becomes difficult to efficiently produce desired piperazine and piperazine derivatives. In addition, the reaction pressure needs to be higher than the pressure at which the reactant exists in a liquid state, that is, the saturated vapor pressure, but in order to obtain a sufficient reaction rate, it is necessary to
A pressure range of 230Kg/cm ² G is suitable;
A range of 100 to 170 kg/cm ² G is particularly preferred. In order to effectively produce piperazine and its derivatives by the method of the present invention, a known batch-type or continuous-type reaction apparatus can be used under the above reaction conditions. A homogeneous or suspended raw material liquid containing a catalyst is introduced into a reactor, where the raw material diethanolamines and ammonia or primary amines are catalytically reacted, and then the reaction liquid is distilled or extracted to form the desired reaction mixture. Separate the reaction products. By collecting the unreacted raw material containing the catalyst and circulating it again to the reactor, the catalyst can be stably and repeatedly used without separation. In the method of the present invention, general-purpose stainless steel is sufficient as the equipment material usually used, but stainless steel with a chromium content of 16 to 22% and a nickel content of 6 to 12% is preferred. Furthermore, stainless steel containing components that improve corrosion resistance, such as molybdenum, tantalum, niobium, and titanium, is also a preferred material. Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 A 100 ml shaking type stainless steel autoclave was filled with 15.4 g of diethanolamine and 45 g of saturated ammonia water, and 1.0 mol% of phosphotungstic acid based on the diethanolamine.
The air in this autoclave space was filled with nitrogen gas.
After purging twice, the autoclave was rapidly heated and heated, and shaken at 290°C and 115 kg/cmG for 3 hours. After rapidly cooling the autoclave, the reaction solution was extracted and the product was analyzed using a gas chromatogram. I went. Piperazine was obtained in 41% yield. Some amount of N-aminoethylpiperazine, monoethanolamine, and triethylenediamine were obtained as by-products. Example 2 The same autoclave as in Example-1 was filled with 15.2 g of diethanolamine and 1.0 mol% of silicotungstic acid based on diethanolamine as a catalyst. After purging the air in the autoclave space three times with nitrogen gas, anhydrous ammonia
12.5g was filled. The autoclave was rapidly heated and heated to 300℃ and 130Kg/cm ² while shaking.
The temperature was controlled with G for 5 hours. After the reaction is complete,
When the reaction solution was rapidly cooled and taken out, analysis revealed that piperazine was obtained in a yield of 48%. Others, some N
-Aminoethyl, ethanolamine, monoetatoluamine, N-aminoethylpiperazine, etc. were produced. Examples 3 to 16 Tests were conducted in the same manner as in Example 1, except that the raw material diethanolamine, the catalyst, and the reaction conditions were changed. The results are shown in Table-1. Furthermore, the results when phosphoric acid was used as a catalyst were shown as a comparative example.

【table】

【table】

Claims (1)

[Claims] 1 General formula () (Here, R ¹ represents hydrogen, a substituted or unsubstituted alkyl group, or an aryl group) and the general formula (), R ² -NH ₂ () (Here, R ² is hydrogen, A heteropolyacid containing at least one metal atom of tungsten, molybdenum, vanadium, group 1 of the periodic table, A method for producing piperazine and piperazine derivatives, characterized in that the reaction is carried out in the presence of a heteropolyacid compound selected from a salt of a Group 2 or Group 8 metal and the heteropolyacid, or an ammonium salt of the heteropolyacid. 2. A patent in which the heteropolyacid compound is a heteropolyacid containing at least one metal atom of tungsten, molybdenum, or vanadium, and is the heteropolyacid salt or ammonium salt with a metal of Group 1 or Group 2 of the Periodic Table. The method according to claim 1. 3. The method of claim 2, wherein the heteropolyacid is phosphomolybdic acid, silicotungstic acid, cobalt tungstic acid, germanotungstic acid, phosphotungstic acid, borotungstic acid or phosphovanadotungstic acid. 4. The method according to claim 1, wherein the reaction is carried out under a pressure of 50 to 250 kg/cm ² G. 5 Diethanolamines and primary amines are
2. The method according to claim 1, wherein the primary amine is used in a proportion of 2 to 20 moles per mole of diethanolamine. 6. The method according to claim 1, wherein the heteropolyacid compound is used in a proportion of 0.1 to 10 mol % based on the diethanolamine. 7. The method according to claim 1, wherein the diethanolamine is diethanolamine and the primary amine is ammonia.