JPH04130135A - Preparation of poly-1,4-ethylenepiperazine compound - Google Patents

Abstract

PURPOSE:To prepare the title compd., which is sol. in various org. solvents, at a high yield at a low temp. without using any catalyst without producing any by-product by reacting a piperazine deriv. with a dihalogenoalkane. CONSTITUTION:A piperazine deriv. [a compd. of formula I (wherein R1 to R8 are each H or alkyl), e.g. piperazine or 2-methylpiperazine] is reacted with a dihalogenoalkane [a compd. of formula II (wherein (n) is 0-3; R9 to R14 are each H or alkyl; and X1 and X2 are each halogen), e.g. ethylene dichloride or 1,2-dichloropropane] to give a poly-1,4-ethylenepiperazine compd. [e.g. a compd. of formula III (wherein (n) is 0-3; (m) is 1 or higher; R1 to R14 are each alkyl; and R15 is a piperazine group), e.g. poly-1,4-ethylenepiperazine]. Thus, poly-1,4-ethylenepiperazine compounds which are sol. in various org. solvent can be prepd. at a very high yield at a low temp. without producing any by- product without using any catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process for producing poly-1,4-ethylenepiperazine.

(Prior Art) Until now, triethylenediamine polymer has been used as a type of poly-1,4-ethylenepiperazine.
One of the most promising methods for its synthesis was ring-opening cationic polymerization of triethylene diamine. For example, a method of polymerization using benzenesulfonic acid as a catalyst for ring-opening cationic polymerization (H., Hall, Journal
ofOrganic Chemistry 28 (
196B), 223), a method of polymerization at high temperature using an organometallic or Friedelkraff catalyst or without a catalyst (Japanese Patent Publication No. 4792/1982), metal halides, organic acids (picric acid, doluosulfone), acid, nitric acid,
perchloric acid), alkyl halides, ammonium salts and quaternary ammonium salts as catalysts (Rasvodovski et al.

Journal of Macromol.

5science Chemistry, 8 (1974
), 242), etc. are known. All of the triethylene diamine polymers polymerized by these methods are pale yellow solids and crystalline, and their average molecular weight is 15,000.
~60,000.

In all polymerizations, inert gas substitution was performed, and the
It is described that the process is carried out under reduced pressure of Hg or less.

Further, Japanese Patent Publication No. 7607/1983 discloses a method for synthesizing a relatively low molecular weight triethylenediamine polymer under a sulfuric acid catalyst.

(Problems to be Solved by the Invention) However, when using conventionally known methods, it is difficult to obtain a triethylenediamine polymer that is soluble in water and organic solvents such as alcohols and glycols, no matter what polymerization conditions are used. I can't.

Furthermore, these methods require various catalysts and require polymerization at high temperatures, and also produce alkylpyrazine and amine oxide as reaction by-products, making purification difficult. In addition, poly-1,4-ethylenepiperazines other than triethylenediamine polymers cannot be obtained by a polymerization method using ring-opening cationic polymerization of triethylenediamine.

The purpose of the present invention is to provide a method for synthesizing soluble thealpoly 1,4-ethylenepiperazines in various organic solvents at low temperatures without using any catalyst and without producing reaction by-products, with extremely high yields. It is about providing.

(Means for Solving the Problems) As a result of intensive studies in view of the above-mentioned current situation, the present inventors have discovered that by using piperazine derivatives and dihalogenated alkanes as raw materials, polymers can be efficiently produced in high yield under extremely easy conditions. It has been discovered that -1,4-ethylenepiperazines can be synthesized.

The details will be explained below.

In the present invention, the piperazine derivative serving as a raw material is a compound represented by the following formula (1).

(In the formula, R1 to R8 are H or an alkyl group.) Specific examples include piperazine and 2-methylpiperazine.

Further, dihalogenated alkanes are compounds represented by the following formula (2).

(In the formula, n is an integer of 0 to 3, R9-14 is H or an alkyl group, and X1-2 are halogen atoms.) Examples include ethylene dichloride, 1,2-dichloropropane,
Examples include 1,3-dichloropropane and 1,4-dichlorobutane, which are available as general reagents.

In addition, poly-1 of the present invention synthesized from the above two types of raw materials,
4-ethylenepiperazines are, for example, represented by the following general formula (3
) is a compound represented by

(In the formula, n is an integer of 0 to 3, m is an integer of 1 or more, R ~
is H or an alkyl group, and R15 is a piperazyl group.

) Specific examples include poly-1,4-ethylenepiperazine, poly-1,4-ethylene(2-methyl)piperazine, and poly-1,4-(1-methyl)ethylenepiperazine.

The most significant feature of the method for synthesizing poly-1,4-ethylenepiperazines in the present invention is that piperazine derivatives and dihalogenated alkanes such as ethylene dichloride are used as raw materials, and as a result, it is possible to synthesize poly-1,4-ethylenepiperazines at low temperatures without using any catalyst. , poly-1,4- which is soluble in various organic solvents with extremely high yield and no reaction by-products.
The point is that ethylene piperazine can be obtained. These reaction conditions are much milder than traditional methods;
Not only is this a simple synthesis method, but it is also possible to obtain highly pure poly-1,4-ethylenepiperazines without any purification treatment after the completion of the reaction.

Specifically, the piperazine derivative represented by the general formula (1) is used in a molar excess amount with respect to the dihalogenated alkane represented by the general formula (2), and the reaction is carried out under reflux using water and/or a lower alcohol as a solvent.

The reaction temperature at this time was about 75 to 85°C, and the reaction time was 4
He is a henchman for about 20 hours. When all the dino-10-genated alkenes have reacted, the temperature of the liquid begins to rise, and this is used as an indication of the completion of the reaction, and the reaction is terminated.

After the reaction is completed, it is treated with caustic soda. Thereafter, the white substance is separated by filtration and washed with a small amount of pure water. This is dried to obtain highly pure poly-1,4 ethylene piperazine. In this case, the yield of the poly-1,4-ethylenepiperazines obtained is virtually 100%, which is extremely high, and also has excellent solubility in neutral and acidic aqueous solutions and organic solvents such as alcohols and glycols. Show your gender.

The poly-1,4-ethylenepiperazines of the present invention are extremely effective as anticaking agents for powders having caking properties, such as triethylenediamine, piperazine, and sodium chloride, just like triethylenediamine according to the conventional method. Furthermore, it is extremely effective as a substance that imparts bewilderment to volatile substances.

(Effects of the Invention) As described above, the present invention provides poly-1,4-ethylenepiperazines that exhibit high solubility in neutral and acidic aqueous solutions and various solvents such as alcohols and glycols, and that This is an innovative synthetic method that allows synthesis in extremely high yields without using any catalyst.

(Example) Specific examples of the present invention are shown below, but the present invention is not limited thereto.

Example 1 Piperazine 86g1 in a flask with an internal volume of 1000Wri
98 g of ethylene dichloride (piperazine/ethylene dichloride>1 (molar ratio)) and 200 mj of pure water! and reflux in an oil bath.

At this time, the liquid temperature was about 83°C. The reaction was continued until the liquid temperature started to rise, and after the reaction was completed, it was sufficiently cooled and an excess amount of caustic soda was added. The produced po'J-1,4-ethylenepiperazine was precipitated, the supernatant was separated, and then separated by filtration. After washing with a small amount of pure water and vacuum drying, poly-1,4-ethylenepiperazine 110
I got g.

The yield was 98%. Molecular weight distribution is 300-1200
The average molecular weight was 600, and it showed excellent solubility in acidic aqueous solutions and organic solvents such as methanol.

Comparative Example 1 Triethylenediamine 35 was added to a flask with an internal volume of 500 d.
0g1 methanol 100rd, 97% concentrated sulfuric acid 0. Ig
(0,0003 mol %) was added and heated with a mantle heater, and the distilled methanol was condensed in a cooling tube and collected.

When the liquid temperature reached 174°C, the distillation valve was closed and the mixture was refluxed for 2 hours. Thereafter, the mixture was allowed to cool to 60°C, and methanol was added to dissolve unreacted monomers. The resulting triethylenediamine polymer was left to stand, precipitated, separated from the supernatant, thoroughly washed with methanol, and dried to obtain 1.7 g of triethylenediamine polymer. The yield at this time was 0.5%, and the obtained triethylenediamine polymer was pale yellow in color and insoluble in water or organic solvents. The molecular weight distribution was 400-7000, and the average molecular weight was 2500.

Comparative Example 2 The same procedure as Comparative Example 1 was conducted except that no catalyst was used. The obtained triethylenediamine polymer weighed 0.1 g, yield was 0.03%, and was pale yellow in color and insoluble in water and organic solvents. The molecular weight distribution was 400 to 13,000, and the average molecular weight was 3,800.

Comparative Example 3 10 g of triethylenediamine and 27.8 mg of dihydrobenzenesulfonate in a high-pressure container with an internal volume of 100 rR1
was placed in the tank, and after sufficient nitrogen substitution, the tank was sealed. This was heated with a mantle heater and reacted at 200°C for 10 hours. Thereafter, the mixture was allowed to cool to 60° C., and methanol was added to dissolve unreacted monomers. Leave it as it is to precipitate the formed triethylenediamine polymer and separate it from the supernatant.
After thorough washing with methanol, it was dried to obtain 9.6 g of triethylenediamine polymer. At this time, the yield was 96%, the molecular weight distribution was 1,000 to 30,000, and the average molecular weight was 8,800. The polymer was pale yellow in color and completely dissociated, and was also insoluble in water and organic solvents.

Example 2 The procedure of Example 1 was repeated except that 100 g of 2-methylpiperazine was used instead of piperazine, and poly-1,4-
122 g of ethylene (2-methyl) piperazine was obtained.

The yield was 98%.

The molecular weight distribution was 400 to 1200, the average molecular weight was 600, and it showed excellent solubility in acidic aqueous solutions and organic solvents such as methanol.

Example 3 The same procedure as in Example 1 was carried out except that 110 g of 1,2-dichloropropane was used instead of ethylene dichloride to obtain 120 g of poly-1,4-(1-methyl)ethylenepiperazine. The yield was 97%. The molecular weight distribution was 300 to 1000, the average molecular weight was 500, and it showed excellent solubility in acidic aqueous solutions and organic solvents such as methanol.

Claims (1)

[Claims] (1) A method for producing poly-1,4-ethylenepiperazines, which comprises reacting a piperazine derivative with a dihalogenated alkane.