JP2010215610A - Method for preparing n-(2-aminoethyl)azole compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for preparing an N-(2-aminoethyl)azole compound, which is a preparation method offering short reaction time, high purification efficiency of a final product, high production efficiency and high safety because a reaction solution undergoes no heat generation or rise of liquid level caused by bubbling. <P>SOLUTION: The method for preparing the N-(2-aminoethyl)azole compound comprises reacting an azole-based compound (A) and an ethylamine derivative (B) having a leaving group at position 2 in the presence of a base (C) in a solvent (D) so as to prepare the N-(2-aminoethyl)azole compound. Here, the ethylamine derivative (B) having the leaving group at position 2 is fed to the reaction system in portions while the reaction system is maintained at 50-200°C. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a compound having a 2-aminoethyl group on a nitrogen atom of an azole skeleton.

Conventionally, it has been known that a compound having a 2-aminoethyl group at the N-position of an azole compound such as imidazole is useful as a pharmaceutical intermediate or a catalyst for various resins.
As a method for producing such an azole compound having a 2-aminoethyl group at the N-position, for example, Patent Document 1 describes a method of hydrolyzing a compound having a 1-acylaminoethyl group. 1 describes a production method in which an azole compound and sodium hydroxide are stirred in toluene or acetonitrile, and then 2-chloroethylamine monohydrochloride and tetrabutylammonium sulfate are added and heated to reflux for 24 hours. ing.

However, in the production method described in Patent Document 1, since a hydrolysis reaction is performed in an aqueous solution, a complicated extraction operation is required after the completion of the reaction. Further, in the extraction operation, the distribution ratio of the final product to the organic solvent is poor. For this reason, there is a problem that a lot of liquid is lost to the water layer and the production efficiency is low.
Further, in the production method described in Non-Patent Document 1, the reaction takes a long time, the yield is not satisfactory, and 2-chloroethylamine monohydrochloride is added all at once to the reaction solution. At a temperature lower than the temperature at which the N-alkylation reaction can proceed, a large amount of aziridine as a reaction intermediate is generated in the middle of the reaction, and the reaction intermediate foams in a solvent and causes a rise in the liquid level of the reaction solution. He had anxiety about the surface.

JP-A-62-198668

SYNTHETIC COMMUNICATIONS, 21 (4), 535-544 (1991)

  In view of this, the present invention is a production method with high production efficiency, with a short reaction time and good purification efficiency of the final product under such a background. It aims at providing the manufacturing method of a high N- (2-aminoethyl) azole type compound.

  However, as a result of intensive studies in view of such circumstances, the present inventors have made an azole compound and an ethylamine derivative having a leaving group at the 2-position to produce an N- (2-aminoethyl) azole compound. The ethylamine derivative, which has been supplied all at once at room temperature, is dividedly fed into the reaction solution at a temperature at which the N-alkylation reaction can proceed, thereby efficiently reducing the temperature of the reaction solution. It has been found that an N- (2-aminoethyl) azole-based compound can be produced safely, and the present invention has been completed.

  That is, the gist of the present invention is that N- (2) is obtained by reacting an azole compound (A) with an ethylamine derivative (B) having a leaving group at the 2-position in a solvent (D) in the presence of a base (C). -Aminoethyl) In the production of an azole compound, an ethylamine derivative having a leaving group at the 2-position is dividedly supplied while maintaining the temperature in the reaction system in the range of 50 ° C to 200 ° C. The present invention relates to a method for producing a-(2-aminoethyl) azole compound.

  In addition, the above-described production method will be produced by way of an example of the production of 1- (2-aminoethyl) -2-methylimidazole via an aziridine which is a reaction intermediate as shown in FIG. 1 below. Is.

[Figure 1]

  According to the present invention, the reaction time can be shortened, the final product can be obtained with a high yield, the purification efficiency of the final product is good, the production efficiency is high, and the liquid level rises due to foaming of the reaction solution. The N- (2-aminoethyl) azole compound can be produced with high safety.

The present invention is described in detail below.
In the present invention, an azole compound (A) and an ethylamine derivative (B) having a leaving group at the 2-position are reacted in a solvent (D) in the presence of a base (C) to give N- (2-aminoethyl) An azole compound is produced. Hereinafter, an azole compound (A), an ethylamine derivative (B) having a leaving group at the 2-position (hereinafter sometimes simply referred to as “ethylamine derivative (B)”), a base (C), and a solvent (D). Will be described sequentially.

  The azole compound (A) in the present invention may be an azole compound having an unsubstituted nitrogen atom in the azole skeleton. For example, a 1H-pyrrole derivative, 1H-imidazole derivative, 1H-pyrazole derivative, 1H- Indole derivatives, 9H-carbazole derivatives, 1H-benzimidazole derivatives, 1H-triazole derivatives, 1H-benzotriazole derivatives, 1H-tetrazole derivatives and the like can be mentioned. Among them, in the present invention, the 1H-imidazole derivative is particularly effective in terms of good reactivity.

  The azole compound (A) may be solid or liquid.

  In the present invention, the ethylamine derivative (B) having a leaving group at the 2-position may be a compound having a leaving group on the carbon atom at the 2-position of ethylamine, and the azole compound (A The hydrogen atoms at the 1-position and 2-position of ethylamine may be substituted with other substituents such as an alkyl group within the range that does not affect the reactivity with.

  As the leaving group of the ethylamine derivative (B), sulfonyl such as halogen atom selected from fluorine atom, chlorine atom, bromine atom and iodine atom, p-toluenesulfonyloxy group, methanesulfonyloxy group, trifluoromethanesulfonyloxy group and the like. An oxy group, a sulfonic acid group, etc. are mentioned, Among these, a halogen atom and a sulfonic acid group are preferable, and a chlorine atom, a bromine atom, and a sulfonic acid group are especially preferable at the point that a raw material is industrially easily available.

  Examples of the ethylamine derivative (B) include 2-chloroethylamine derivatives, 2-bromoethylamine derivatives, 2-iodoethylamine derivatives, 2-fluoroethylamine derivatives, p-toluenesulfonic acid (2-aminoethyl) ester derivatives, methanesulfonic acid. It is preferably at least one selected from (2-aminoethyl) ester derivatives, trifluoromethanesulfonic acid (2-aminoethyl) ester derivatives, and 2-aminoethylsulfuric acid ester derivatives, and in particular, in the case of 2-chloroethylamine derivatives Is particularly effective in terms of good reactivity and industrial availability of raw materials.

The ethylamine derivative (B) may be either liquid or solid, and divided and supplied as it is in a mixed solution containing the azole compound (A), the base (C), and the solvent (D), or What is necessary is just to divide and supply by making it melt | dissolve or disperse | distribute to a suitable solvent.
Further, when the ethylamine derivative (B) is an acid salt, the acid salt is converted into a free amine using a base in a solvent to remove a by-product salt, and then the azole compound (A), base ( C) It is preferable to divide and supply into the mixed solution containing the solvent (D).

  The amount of the ethylamine derivative (B) used is usually 0.9 to 3 equivalents, preferably 1 to 2.5 equivalents, relative to the azole compound (A). If the amount used is too large, unreacted ethylamine derivative (B) or aziridine as a reaction intermediate tends to remain in the reaction system, and if it is too small, unreacted azole compound (A) remains. It tends to reduce yield and quality.

  Examples of the base (C) in the present invention include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, mixtures of alkali metal hydroxides and carbonates such as a mixture of potassium hydroxide and potassium carbonate, and the like. Inorganic bases, metal alkoxides such as sodium methoxide, sodium ethoxide, potassium t-butoxide, and organic bases such as DBU (diazabicycloundecene) and triethylamine. Or two or more types can be used in combination. Among these, an alkali metal hydroxide is preferable in terms of high reactivity, and sodium hydroxide and potassium hydroxide are particularly preferable.

  The amount of the base (C) to be used is generally 1 to 5 equivalents, preferably 1.1 to 4 equivalents, particularly preferably 1.2 to 3.5 equivalents, relative to the azole compound (A). When an acid salt of an ethylamine derivative is used, the base (C) may be used by adding one more equivalent to the acid salt of the ethylamine derivative. When the amount of the base (C) used is too large, the slurry concentration tends to be high and it becomes difficult to stir. When the amount is too small, the unreacted azole compound (A) remains and the yield and quality tend to decrease. There is.

  The solvent (D) in the present invention may be appropriately selected in consideration of the boiling point of the solvent, the polarity, the solubility of the raw material compound, and the like. For example, nitrile solvents such as acetonitrile, N, N-dimethylacetamide, N, N -Amide solvents such as dimethylformamide and N-methylpyrrolidone, aprotic polar solvents such as dimethyl sulfoxide, ether solvents such as tetrahydrofuran, cyclopentyl methyl ether and t-butyl methyl ether, hydrocarbon solvents such as toluene, etc. Examples of the organic solvent include nitrile solvents, amide solvents, aprotic polar solvents, and hydrocarbon solvents, and acetonitrile, N, N-dimethylacetamide, N, N-dimethyl are preferable. Formamide and toluene are particularly preferred. These specific solvents can be used alone or in combination of two or more.

  The amount of the solvent (D) to be used is generally 1 to 20 times (weight basis), preferably 3 to 15 times (weight basis) with respect to the azole compound (A). If the amount used is too large, the reaction time tends to be prolonged, and if it is too small, the slurry concentration tends to be high and stirring becomes difficult.

  Thus, an N- (2-aminoethyl) azole compound is produced using the components (A) to (D). In the present invention, the azole compound (A), the base (C), The ethylamino derivative (B) is dividedly supplied into the mixed solution containing the solvent (D) while maintaining the temperature in the reaction system in the range of 50 to 200 ° C.

  The temperature in the reaction system represents the temperature of the reaction solution, and needs to be 50 to 200 ° C, preferably 55 to 190 ° C, particularly preferably 60 to 180 ° C. If the temperature is too low, the reaction rate is slowed and the yield is reduced. If the temperature is too high, by-products are increased, and the yield and quality are reduced.

Examples of the split supply method of the ethylamine derivative (B) include a method in which the ethylamine derivative (B) is dropped as it is or a solution in which the ethylamine derivative (B) is dissolved in the solvent (D). When (B) is a solid, the solid is dissolved or dispersed in an appropriate solvent and then dropped into a mixed solution containing the azole compound (A), the base (B), and the solvent (D). It is preferable.
In addition, since the reaction of the present invention is an exothermic reaction and heat is generated by the dropping of the ethylamine derivative (B), the dropping rate of the ethylamine derivative (B) is such that the temperature in the reaction system is within the above range. It is preferable to dripping.

The supply time is usually 0.1 hours or longer, preferably 0.2 hours or longer. If the dropping time is too short, aziridine, a reaction intermediate generated in the reaction system, volatilizes and foams. There is a tendency that the liquid level rises due to or the yield decreases.
The upper limit of the dropping time is usually within 5 hours, preferably within 4 hours. If the dropping time is too long, the manufacturing time is prolonged and the manufacturing cost tends to increase, which tends to be uneconomical.

After completion of divided supply, the reaction is preferably allowed to proceed with stirring while maintaining the above temperature range until the end of the reaction. The reaction time after completion of divided supply is usually 0.1 to 10 hours, preferably 0. The reaction may be performed for 5 to 8 hours.
In addition, the time of completion | finish of reaction in this invention is the stage where the number-of-moles of the produced | generated N- (2-aminoethyl) azole type compound in the reaction liquid with respect to the number-of-feed mol number of azole type compound (A) became constant. That means.

As a reaction apparatus used for manufacture of this invention, it can carry out using the reaction apparatus provided with the thermometer, the reflux condenser, the stirring apparatus, the inert gas inflow installation, and the preparation apparatus, for example.
Examples of the material of the reactor include stainless steel (SUS) and glass.
The stirring method is not particularly limited as long as the contents can be sufficiently mixed. Regarding the pressure at the time of production, it may be usually performed at normal pressure.

  After completion of the reaction, the desired N- (2-aminoethyl) azole compound can be obtained by isolating, purifying, and drying the reaction product.

In isolation of the reaction product, the by-product inorganic salt may be filtered off by a filtration operation such as Nutsche filtration or centrifugal filtration, and the product may be collected as a solution. In addition, when performing filtration, you may cool a reaction liquid in the range without a trouble.
The filtered solution containing the product may be concentrated under normal pressure or reduced pressure, but it is preferably concentrated under reduced pressure from the viewpoint of production efficiency.
A purified N- (2-aminoethyl) azole compound is obtained by appropriately purifying the concentrated solution containing the product obtained by the concentration treatment by conventional means such as column purification, distillation, recrystallization and the like. It is.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the examples, “parts” and “%” mean weight basis unless otherwise specified.

<Production Example 1> “Method for producing acetonitrile solution of 2-chloroethylamine”
A 2 l reactor was charged with 174.0 g (1.50 mol) of 2-chloroethylamine hydrochloride and 650 ml of acetonitrile under a nitrogen atmosphere, and cooled to a liquid temperature of 5 ° C. Thereafter, 151.8 g (1.50 mol) of triethylamine was added dropwise over 0.5 hour, and the mixture was reacted at 5 ° C. for 1 hour. After completion of the reaction, the by-product organic salt was removed from the reaction solution by filtration to obtain an acetonitrile solution of 2-chloroethylamine (2-chloroethylamine content: 119.3 g (1.50 mol)). The yield was 100%.

<Example 1> “Method for producing 1- (2-aminoethyl) -2-methylimidazole”
A 2-liter reactor was charged with 82.1 g (1.00 mol) of 2-methylimidazole (A) and 410 ml of acetonitrile (D), and 120.0 g (3.00 mol) of sodium hydroxide (C) was added to the solution. Aging was performed at 25 ° C. for 0.5 hour. After completion of aging, the liquid temperature was raised to 75 ° C., and a solution of 2-chloroethylamine (B) in acetonitrile (D) prepared in “Production Example 1” (2-chloroethylamine content: 119.3 g (1.50 mol)) ) Was added dropwise over 0.5 hour, and then reacted at 75 ° C. for 2 hours. After completion of the reaction, the liquid temperature was cooled to 30 ° C., and inorganic salts by-produced from the reaction liquid were removed by filtration. The filtrate was concentrated under reduced pressure to obtain 117.8 g of crude 1- (2-aminoethyl) -2-methylimidazole. The yield was 94%.

<Example 2> “Method for producing 1- (2-aminoethyl) pyrazole”
A 200 ml reactor was charged with 5.5 g (0.08 mol) of pyrazole (A) and 27 ml of acetonitrile (D), and 9.6 g (0.24 mol) of sodium hydroxide (C) was added to the solution, and the reaction was carried out at 25 ° C. Aged for 0.5 hour. After completion of aging, the liquid temperature was raised to 75 ° C., and the acetonitrile (D) solution of 2-chloroethylamine (B) prepared in “Production Example 1” (2-chloroethylamine content: 9.5 g (0.12 mol)) ) Was added dropwise over 0.5 hour, and then reacted at 75 ° C. for 5 hours. After completion of the reaction, the liquid temperature was cooled to 30 ° C., and inorganic salts by-produced from the reaction liquid were removed by filtration. The filtrate was concentrated under reduced pressure to obtain 8.4 g of crude 1- (2-aminoethyl) pyrazole. The yield was 93%.

<Example 3> “Method for producing 1- (2-aminoethyl) benzimidazole”
A 200 ml reactor was charged with 5.0 g (0.04 mol) of benzimidazole (A) and 25 ml of toluene (D), and 5.1 g (0.13 mol) of sodium hydroxide (C) was added to this solution. For 0.5 hours. After completion of aging, the liquid temperature was raised to 75 ° C., and the acetonitrile (D) solution of 2-chloroethylamine (B) prepared in “Production Example 1” (2-chloroethylamine content: 5.0 g (0.06 mol)) ) Was added dropwise over 0.5 hours, and then reacted at 75 ° C. for 7 hours. After completion of the reaction, the liquid temperature was cooled to 30 ° C., and inorganic salts by-produced from the reaction liquid were removed by filtration. The filtrate was concentrated under reduced pressure to obtain 5.5 g of crude 1- (2-aminoethyl) benzimidazole. The yield was 80%.

<Comparative Example 1> “Method for producing 1- (2-aminoethyl) -2-methylimidazole”
A 100 ml reactor was charged with 6.6 g (0.08 mol) of 2-methylimidazole and 40 ml of acetonitrile, and 11.5 g (0.29 mol) of sodium hydroxide was added to the solution, followed by aging at 20 ° C. for 0.5 hour. It was. After completion of ripening, 1.1 g (3.2 mmol) of tetrabutylammonium sulfate and 10.0 g (0.08 mol) of 2-chloroethylamine hydrochloride were added, and the mixture was heated to 75 ° C. at the same temperature. For 24 hours. After completion of the reaction, the liquid temperature was cooled to 30 ° C., inorganic salts formed as a by-product from the reaction liquid were removed by filtration, and the filtrate was concentrated under reduced pressure to give crude 1- (2-aminoethyl) -2- 4.8 g of methylimidazole was obtained. The yield was 48%.

In the production method of Comparative Example 1, when the reaction temperature is increased after the addition of 2-chloroethylamine hydrochloride, a large amount of the reaction intermediate aziridine is generated and rises to 75 ° C. above the boiling point (about 60 ° C.) of aziridine. As a result, the reaction system is in a reflux state, and as a result, the liquid level of the reaction solution accompanying foaming may increase or the internal pressure may increase due to volatilized aziridine.
In addition, the amount of inorganic salt by-produced in the reaction solution is large, the slurry concentration is high, and stirring is difficult, which is disadvantageous for industrial production.

<Comparative Example 2> “Method for producing 1- (2-aminoethyl) -2-methylimidazole”
A 200 ml reactor was charged with 6.6 g (0.08 mol) of 2-methylimidazole and 35 ml of acetonitrile, and 9.6 g (0.24 mol) of sodium hydroxide was added to this solution, followed by aging at 25 ° C. for 0.5 hour. It was. After completion of the aging, the liquid temperature was raised to 75 ° C., and the acetonitrile solution of 2-chloroethylamine prepared in the same manner as in “Production Example 1” (2-chloroethylamine content: 9.5 g (0.12 mol)) was batched. The mixture was charged and reacted at 75 ° C. for 2 hours. After completion of the reaction, the liquid temperature was cooled to 30 ° C., and inorganic salts by-produced from the reaction liquid were removed by filtration. The filtrate was concentrated under reduced pressure to obtain 7.4 g of crude 1- (2-aminoethyl) -2-methylimidazole. The yield was 74%.

  When the acetonitrile solution of 2-chloroethylamine was charged at 75 ° C. as in Comparative Example 2, a large amount of aziridine, which is a reaction intermediate, was generated after the addition in the same manner as in Comparative Example 1. Since aziridine was brought into a reflux state from the middle and accompanied by a rise in the reaction liquid level accompanying foaming and an increase in internal pressure, it was disadvantageous for industrial production.

<Comparative Example 3> “Method for producing 1- (2-aminoethyl) -2-methylimidazole”
A 200 ml reactor was charged with 6.6 g (0.08 mol) of 2-methylimidazole and 35 ml of acetonitrile, and 9.6 g (0.24 mol) of sodium hydroxide was added to this solution, followed by aging at 25 ° C. for 0.5 hour. It was. After completion of the aging, an acetonitrile solution of 2-chloroethylamine prepared in the same manner as in “Production Example 1” (2-chloroethylamine content: 9.5 g (0.12 mol)) was added dropwise over 0.5 hour, and the liquid temperature The temperature was raised to 75 ° C. After reacting at 75 ° C. for 2 hours, the liquid temperature was cooled to 30 ° C., and the inorganic salt by-produced from the reaction liquid was removed by filtration. The filtrate was concentrated under reduced pressure to obtain 7.7 g of crude 1- (2-aminoethyl) -2-methylimidazole. The yield was 77%.

  As in Comparative Example 3, when the acetonitrile solution of 2-chloroethylamine was dividedly charged at 25 ° C. and the temperature was raised to 75 ° C. and the reaction was allowed to proceed, Since a large amount of aziridine, which is a body, is generated, the aziridine is refluxed in the middle of the reaction, accompanied by a rise in the liquid level of the reaction solution accompanied by foaming and an increase in internal pressure, it was disadvantageous for industrial production.

  As described above, when the reaction solution is brought to a high temperature of 75 ° C. and an acetonitrile solution of 2-chloroethylamine is supplied dropwise to the reaction solution as in Examples 1 to 3, the yield is high and the safety is high. It can be seen that it is possible to produce an N- (2-aminoethyl) azole compound while maintaining the above.

  By using the production method of the present invention, it is possible to produce an N- (2-aminoethyl) azole compound with high productivity, and the obtained N- (2-aminoethyl) azole compound is a pharmaceutical intermediate or It is useful as a catalyst for various resins.

Claims (3)

  An N- (2-aminoethyl) azole compound is reacted by reacting an azole compound (A) with an ethylamine derivative (B) having a leaving group at the 2-position in the presence of a base (C) in a solvent (D). In the production, N- (2-aminoethyl) is characterized in that the ethylamine derivative (B) having a leaving group at the 2-position is dividedly supplied while maintaining the temperature in the reaction system in the range of 50 to 200 ° C. ) A method for producing an azole compound.   The azole compound (A) is a 1H-pyrrole derivative, 1H-imidazole derivative, 1H-pyrazole derivative, 1H-indole derivative, 9H-carbazole derivative, 1H-benzimidazole derivative, 1H-triazole derivative, 1H-benzotriazole derivative, The method for producing an N- (2-aminoethyl) azole compound according to claim 1, wherein the method is at least one selected from 1H-tetrazole derivatives.   An ethylamine derivative (B) having a leaving group at the 2-position is a 2-chloroethylamine derivative, 2-bromoethylamine derivative, 2-iodoethylamine derivative, 2-fluoroethylamine derivative, p-toluenesulfonic acid (2-aminoethyl) It is at least one selected from an ester derivative, a methanesulfonic acid (2-aminoethyl) ester derivative, a trifluoromethanesulfonic acid (2-aminoethyl) ester derivative, and a 2-aminoethyl sulfate ester derivative. A method for producing an N- (2-aminoethyl) azole compound according to 1 or 2.