JP2001097896A - Method for producing alkylcyclopentadiene compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an alkylcyclopentadiene compound useful as a synthetic precursor for a fine chemical intermediate, a medicine intermediate, an agrochemical intermediate and a synthetic precursor for a catalyst for olefin polymerization such as a metallocene catalyst by a simple operation not requiring an extremely anhydrous condition and yet by using inexpensive reagents. SOLUTION: This method for producing an alkylcyclopentadiene compound comprises two processes of (I) a process for preparing a cyclopentadienyl metal from cyclopentadiene and a metal hydroxide (preparation process of cyclopentadienyl metal) and (II) a process for reacting the cyclopentadienyl metal with an alkylating agent in the presence of at least one kind of solvent selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide and 1,3-dimethyl-2-imidazolidinone to collect the objective alkylcyclopentadiene compound (alkylation process).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an alkylcyclopentadiene compound. Alkylcyclopentadiene compounds are useful as synthetic precursors for fine chemical intermediates, pharmaceutical and agricultural chemical intermediates, and as olefin polymerization catalysts such as metallocene catalysts.

[0002]

2. Description of the Related Art Various methods have been known for producing alkylcyclopentadiene compounds. (1) A method of reacting cyclopentadiene and an aliphatic lower alcohol in the gas phase in the presence of a catalyst (Japanese Patent Publication No. 4-272)
No. 15) and a method of reacting cyclopentadiene and ethylene in a gas phase on a hydrocarbon (Journal of the Chemical Society of Japan, 1977).
(3), p. 375 (1977)). (2) A method of reacting metal sodium and cyclopentadiene in liquid ammonia and then reacting an equivalent amount of an alkyl halide (Izv. Vyssh. Vchebn.
Zaved. , Khim. Khim. Techno
l. , 19 (10), pp. 1511 (1970)).

(3) A cyclopentadienyl metal solution is obtained from sodium metal and cyclopentadiene in an organic solvent such as dimethoxyethane or diglyme, and the solution is added dropwise to an alkylating agent to obtain a 1- or 5-form. Method (Te
trahedron, vol. 21 and 21313 (19
65)). (4) As a first step of a method for producing a norbornene derivative, a method in which sodium hydride and cyclopentadiene are reacted in tetrahydrofuran solvent to produce cyclopentadienyl sodium, and an alkylating agent is added dropwise thereto at a low temperature. Are described in Examples (Japanese Patent Laid-Open No.
4-63063). (5) A method of selectively obtaining 1-alkylcyclopentadiene by reacting a Grignard reagent of cyclopentadiene with an alkyl halide or alkyl sulfate (Montas
ch. Chemie. , 91, 805, 812 (1
960)).

(6) As the first step of the process for producing prostaglandins, cyclopentadienyllithium is obtained from cyclopentadiene and alkyllithium,
A method of reacting ethyl bromoheptanoate to obtain a 1-isomer (JP-B-53-33583) is disclosed. (7) As a similar method, there is a method for alkylating a cyclopentadiene-based compound, which comprises reacting a cyclopentadiene-based compound with an alkyl lithium, adding an aprotic polar solvent, and allowing an alkylating agent to act. It is disclosed (JP-A-10-25258).

(8) As the first step of the process for producing optically active cyclopentenediol, there is disclosed a method of reacting cyclopentadiene with an alkylating agent in the presence of a base to obtain alkylcyclopentadiene (JP-A-6-23).
No. 9779). The types of alkylating agents are comprehensively exemplified, and as a base, alkali metals, alkaline earth metals, metal hydrides, alkali metal alkoxides and the like are widely described.Also, as for the reaction solvent, diethyl ether, n-hexane, Examples include tetrahydrofuran, N, N-dimethylformamide, dimethylsulfoxide, and the like, which states that almost any solvent may be used as long as it does not adversely affect the reaction. However, in the examples, only the example of reacting sodium hydride and cyclopentadiene in tetrahydrofuran solvent to produce cyclopentadienyl sodium, and then dropping the alkylating agent at low temperature, there is only an example, This is exactly the same method as in the prior art (4).

In the method (1), a special apparatus is required for a gas phase reaction, and a mixture of alkylcyclopentadiene having different degrees of substitution is required, so that a complicated operation is required for purification. The method (2) uses a reagent that needs to be handled at a very low temperature or under pressure, such as liquid ammonia, and uses a reagent that is extremely difficult to handle, such as sodium metal, that reacts with moisture in the air. It is a difficult point. (3), (4), (5), (6), (7)
Methods (8) and (8) also require extreme water-prohibiting conditions, such as sodium metal, sodium hydride, Grignard reagents and alkyllithiums, and are generally expensive,
There are difficulties in industrial implementation.

Further, as a method using a metal hydroxide,
The following methods are known. (9) In the presence of a phase transfer catalyst such as a quaternary ammonium salt,
A method of reacting cyclopentadiene with an alkyl halide in an aqueous solution of a metal hydroxide (US Pat. No. 35605)
No. 83). However, in this method, the reaction does not occur unless the alkyl chain of the quaternary ammonium salt used is long, and such a catalyst is contained in the same organic phase as the product alkylcyclopentadiene after the reaction, In order to separate the product alkylcyclopentadiene and the quaternary ammonium salt, a complicated operation such as repeating washing with a large amount of water many times or distilling off the product alkylcyclopentadiene is required. In addition, quaternary ammonium salts used as catalysts are generally expensive, and must be recovered and reused, and the recovery operation is complicated.

(10) A method of reacting cyclopentadiene with an alkali metal hydroxide in an organic solvent in the presence of a dehydrating agent such as calcium oxide to generate a cyclopentadienyl metal, and allowing an alkyl halide to act on the metal (Russian Patent No. 520341). In this method, to coexist a solid dehydrating agent such as calcium oxide,
After the completion of the reaction, the hydrated solid calcium oxide must be separated and removed from the reaction solution, but it is difficult to carry out the reaction industrially. For example, when the alkylation is carried out in a tank reactor and the slurry-like reaction liquid is withdrawn from the bottom end of the reactor after the reaction, this solid calcium oxide causes clogging at the bottom end valve. It is.

[0009] As described above, generally, expensive and extreme water-prohibiting conditions such as simple metals such as sodium metal, metal hydrides such as sodium hydride, Grignard reagents and alkyllithiums have been required. When using a metal hydroxide or using a metal hydroxide, only a method using a phase transfer catalyst such as a quaternary ammonium salt or a solid dehydrating agent such as calcium oxide, which requires complicated post-treatment operations, can be used. Was not known. Therefore, as a method for producing an alkylcyclopentadiene compound, a method that is inexpensive, does not require extreme non-aqueous conditions, and is easy to operate has been desired.

[0010]

SUMMARY OF THE INVENTION The present invention provides a method for producing an alkylpentadiene compound from a cyclopentadiene compound, which is inexpensive and requires no extreme non-aqueous conditions and is easy to operate.

[0011]

Means for Solving the Problems The present inventors have made intensive studies on the above problems, and as a result, completed the present invention. That is, (1) a cyclopentadiene compound and an alkylating agent represented by the general formula RX (R is an unsubstituted or substituted aliphatic hydrocarbon group, X is a halogen or a tosyl group or an alkylsulfonate group), A method for producing an alkylcyclopentadiene compound, comprising the following two steps in a method for obtaining a pentadiene compound. (I) A step of preparing a cyclopentadienyl metal from cyclopentadiene and a metal hydroxide (cyclopentadienyl metal preparation step). (II) The cyclopentadienyl metal and the alkylating agent are present in the presence of at least one solvent selected from the group consisting of dimethyl sulfoxide, N, N-dimethylformamide and 1,3-dimethyl-2-imidazolidinone A step of reacting below to obtain an alkylcyclopentadiene compound (alkylation step). (2) In the cyclopentadienyl metal preparation step, the metal hydroxide is potassium hydroxide,
The method for producing an alkylcyclopentadiene compound according to the above (1). (3) The method for producing an alkylcyclopentadiene compound according to the above (1) or (2), wherein the step of preparing a cyclopentadienyl metal and the step of alkylating are performed in an inert gas atmosphere.

Hereinafter, the present invention will be described in detail. The cyclopentadiene compound referred to in the present invention is represented by the following general formula (1)

Embedded image Represented by the general formula R _5-
It is represented by X. However, R ₁ to R ₅ represent hydrogen or a linear or branched alkyl group, alkenyl group, alkynyl group, or cycloalkyl group, and may be linear or branched. Further, an unsaturated bond may be contained. Further, a hetero atom such as oxygen, silicon, or halogen may be contained. Examples of the alkyl group include:
Methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, 2-propenyl, 2-butenyl, 3-butenyl, 2-hexenyl, 5-hexenyl and the like can be mentioned. An alkenyl group has the general formula -CH =
An alkynyl group represented by the formula: C ₉ R ₁₀
H = C−R ₉ . R ₉ and R ₁₀ are hydrogen or a hydrocarbon group, for example, methyl, ethyl, n-propyl,
Isopropyl, n-butyl, sec-butyl, tert
-Butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1- Dimethylbutyl, n-hexyl, n-octyl, n-nonyl, n
-Decyl, n-undecyl, n-dodecyl, 2-propenyl, 2-butenyl, 3-butenyl, 2-hexenyl,
5-hexenyl and the like. Examples of the cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, 1-cyclopenten-1-yl, 2-cyclopenten-1-yl, cyclopentadienyl, cyclohexyl, 1-cyclohexen-1-yl, and 2-cyclohexen-1 -Yl, 3-cyclohexen-1-yl,
1,3-cyclohexadien-1-yl, 2,4-cyclohexadien-1-yl, cycloheptyl, 1-cyclohepten-1-yl, 2-cyclohepten-1-yl, 3-cyclohepten-1-yl, -Cyclohepten-1-yl, cyclooctyl, 1-cyclooctene-
Examples include 1-yl, 2-cycloocten-1-yl, cyclononyl, cyclodecyl and the like. As shall include oxygen, include those with a substituent represented by the general formula -OR ₁₁ or formula -COOR ₁₂ in groups mentioned before. R ₁₁ and R ₁₂ are hydrogen or a hydrocarbon group, for example, methyl, ethyl, n-propyl, isopropyl, n
-Butyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl,
-Methylpentyl, 1,1-dimethylbutyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, 2-propenyl, 2-butenyl, 3-butenyl, 2-hexenyl , 5-hexenyl and the like. Further, the groups described so far may contain halogens such as silicon, fluorine, chlorine, bromine and iodine. X represents a halogen atom, a paratoluenesulfonate group or an alkylsulfonate group.

In the step of preparing cyclopentadienyl metal, cyclopentadiene is reacted with a metal hydroxide in a solvent,
This is a step of generating a cyclopentadienyl metal. In a solvent, the cyclopentadienyl metal is actually ionized and dissolved in a cyclopentadienyl anion and a metal ion. The metal hydroxide acts as a base that abstracts hydrogen from cyclopentadiene. As a base, in the prior art, a simple metal, a metal hydride, an alkyllithium, a Grignard reagent, etc. are used, but as described in the description of the prior art, there is a danger of ignition due to reaction with moisture in the air. Be careful on above and are generally expensive. In the present invention, the base used in the cyclopentadienyl metal preparation step is a metal hydroxide, which is inexpensive without such ignition risk. Metal hydroxides are hydroxides of alkali metals, for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide,
Calcium hydroxide, barium hydroxide and the like,
Preferably, it is sodium hydroxide or potassium hydroxide. However, in the case of sodium hydroxide, when a cyclopentadienyl metal is prepared by reacting with cyclopentadiene, a precipitate is often generated, and in this case, potassium hydroxide is preferably used. When potassium hydroxide is used, a commercially available grade may be used irrespective of a flake shape, a granular shape, or an aqueous solution.

As the solvent used for preparing the cyclopentadienyl metal, any solvent can be used as long as it can dissolve the cyclopentadienyl metal, and no special treatment such as dehydration is required. Absent. However, in the case of a solvent that adversely affects the reaction with the alkylating agent in the next alkylation step, a step of once distilling off the solvent after preparing the cyclopentadienyl metal and before reacting with the alkylating agent is required. It becomes complicated. Therefore, it is preferable to use the solvent used in the subsequent alkylation step also in the preparation of the cyclopentadienyl metal from the viewpoint of eliminating the solvent distillation step. The quantitative ratio between cyclopentadiene and metal hydroxide is not particularly limited. Generally, the molar ratio of metal hydroxide to cyclopentadiene is in the range of 0.1 to 10, preferably in the range of 0.5 to 2, more preferably in the range of 0.8 to 1.5. is there.

The reaction temperature at the time of preparing cyclopentadienyl metal can be employed from -10 ° C. to the boiling point of the solvent.
If the amount is too low, the reaction does not easily proceed. If the amount is too high, the dimerization of the cyclopentadiene compound tends to proceed.
C. to 80C, more preferably 10C to 50C. The pressure can be carried out at normal pressure or under pressure. When a cyclopentadiene compound having a low boiling point is used as a raw material, when the reaction is carried out in a normal pressure-open system, it is better to carry out the reaction in a reactor equipped with a reflux condenser in order to prevent loss of the cyclopentadiene compound. Further, since the reaction between the cyclopentadiene compound and the metal hydroxide is an exothermic reaction, it is better to add a device for maintaining a predetermined reaction temperature to the reactor. Further, since cyclopentadienyl metal is easily oxidized by oxygen in the air, it is preferable to seal the reaction system with an inert gas such as nitrogen to prevent oxidation. Otherwise,
This is because during the next alkylation step, by-products derived from the oxidation of the cyclopentadienyl metal are generated in the reaction system, which may cause clogging of the valve at the bottom end of the reactor in a post-treatment operation. . The reaction time is usually from 10 minutes to 6 hours. When the same solvent used in the next step of the alkylation step is used as the solvent during the preparation of the cyclopentadienyl metal, the cyclopentadienyl metal solution obtained in this step can be used as an alkyl without any post-treatment. Can be subjected to a chemical conversion step. The alkylation step is a step of obtaining an alkylcyclopentadiene compound by reacting the cyclopentadienyl metal obtained in the previous step with an alkylating agent.

The solvent in the alkylation step is a reaction between a cyclopentadienyl metal and an alkylating agent, since the first step is that the cyclopentadienyl anion in the cyclopentadienyl metal nucleophilically attacks the alkylating agent. Solvents having low solvation with respect to cyclopentadienyl anion are preferred. Therefore, it does not have acidic hydrogen such as hydrogen bond, has small solvation to anions, and strongly dissolves cyclopentadienyl metal by strongly solvating metal ions of cyclopentadienyl metal with strong polarity. Solvent, that is, an aprotic polar solvent. Among them, the solvent from which the alkylcyclopentadiene compound is obtained in high yield is a solvent composed of at least one selected from dimethylsulfoxide, N, N-dimethylformamide and 1,3-dimethyl-2-imidaziridinone. Even with the same aprotic polar solvent, tetrahydrofuran generates a large amount of insolubles during the preparation of cyclopentadienyl metal, does not produce alkylcyclopentadiene at all even when alkylation is performed, and in the case of acetonitrile, The reactivity with the alkylating agent is low, and the yield does not reach 50%. When these solvents are used, there is no need for a special dehydration operation as in the case of using simple metals or metal hydrides. These three solvents have been found to achieve high yields even when metal hydroxide is used as a raw material. When these solvents are used, phase transfer catalysts and dehydrating agents such as calcium oxide, which are difficult to perform after-treatment, are used. The fact that they are not required is based on detailed studies by the present inventors and cannot be easily inferred from the prior art.

The quantitative ratio between the cyclopentadienyl metal and the alkylating agent is not particularly limited. The molar ratio of the isopropylating agent to the cyclopentadienyl metal is
Usually, it is in the range of 0.1 to 10. Preferably 0.5
To 3, more preferably 0.8 to 1.2. The reaction temperature of the isopropylation step is in the range of -20C to 80C, preferably in the range of -10C to 50C. More preferably, it is in the range of -5 to 30C. −
At a temperature lower than 20 ° C., the reaction is slow, and at a temperature higher than 80 ° C., the dimerization of the formed alkylcyclopentadiene compound tends to proceed. The pressure may be normal pressure or pressurized. As the reaction operation, the isopropylating agent may be added dropwise or little by little to the cyclopentadienyl metal solution, or the cyclopentadienyl metal solution may be added dropwise or little by little to the isopropylating agent. The reaction in this step is an exothermic reaction, and if the reaction device can effectively remove the heat generated by the reaction and maintain the reaction temperature within the above temperature range, the cyclopentadienyl metal and the isopropylating agent are mixed at once. Alternatively, a reaction may be caused at the same time. A type in which both are fed and reacted in a tubular reactor having a stirring and mixing action such as a static mixer may be used.

In the present invention, there is no need to perform a special dehydration operation on the solvent and raw materials used as described above. This is a great advantage when recovering and reusing the solvent and the like. When the reaction between the cyclopentadienyl metal and the alkylating agent is carried out in a tank reactor, the reaction is preferably carried out with stirring. Preferably 0.1 per cubic meter of the reaction solution
It is preferred to carry out with a stirring intensity of kW or more. More preferably, the power is 0.2 kW or more per cubic meter of the reaction solution. This is because if it is less than 0.1 kW / m ³ , the reaction proceeds slowly. During the cyclopentadienyl metal preparation step and the alkylation step, it is preferable to seal the reaction system with an inert gas such as nitrogen. This is because the cyclopentadienyl metal is easily oxidized by oxygen in the air. When the oxidation of cyclopentadienyl metal occurs, in the post-treatment operation after the alkylation step described below, insolubles float near the liquid-liquid interface of the reaction solution in a two-liquid phase, making separation operation difficult. Because it may cause In severe cases, this insoluble matter causes clogging of the valve at the bottom end of the reactor.

The post-treatment operation after the completion of the alkylation is generally as follows. After adding a mineral acid such as hydrochloric acid or sulfuric acid to neutralize a small amount of alkali contained in the reaction end solution,
Add a hydrocarbon such as hexane. The reaction system is a two-liquid phase, and the lower phase containing water and the solvent used in the alkylation step may be extracted and separated from the upper phase comprising the product alkylcyclopentadiene compound and hydrocarbon. As another method, hexane may be added to the reaction-terminated liquid to make the reaction system a two-liquid phase, the lower phase may be extracted, and the upper phase may be repeatedly washed with water until the alkali content is eliminated. As a further alternative, a hydrocarbon such as hexane may be added at the beginning or during the alkylation step. Further, when dimethyl sulfoxide is used as a solvent in the alkylation step, the reaction termination solution is already a lower phase mainly composed of dimethyl sulfoxide,
Since the product alkylcyclopentadiene compound is a two-liquid phase of the upper phase of the main component, the phase separation operation may be performed as it is, and the upper phase may be washed with water or neutralized with an acid.
The method of the present invention will be described by the following examples, but the present invention is not limited by the following examples.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.
The analysis conditions of the product of the present invention by gas chromatography are shown below. 1. Alkylcyclopentadiene analyzer: Shimadzu GC-14A, Shimadzu Chromatopack CR-4A Column: J & W Scientific Capillary Column DB-1 (length 30 m × inner diameter 0.25 mm, liquid phase film thickness 0.25 μm) Temperature Conditions: Column 40 ° C. × 5 minutes → 250 ° C. (10 ° C. /
Minutes). Inlet 60 ° C, detector 250 ° C (FID)

The reagents used in the examples of the present invention are as follows.・ 16 cyclopentadiene dicyclopentadiene (manufactured by Wako Pure Chemical Industries, Ltd.)
Produced by pyrolysis at 0 ° C. -Potassium hydroxide 85% potassium hydroxide: manufactured by Katayama Chemical Industry Co., Ltd. 49% potassium hydroxide: manufactured by Daiso Co., Ltd.-Isopropyl bromide: manufactured by Tokyo Chemical Industry Co., Ltd.-Dimethyl sulfoxide: Wako Pure Chemical Industries, Ltd. Special grade n-Propyl bromide: manufactured by Tokyo Chemical Industry Co., Ltd.Ethyl bromide: manufactured by Tokyo Chemical Industry Co., Ltd.Acetonitrile: special grade manufactured by Wako Pure Chemical Industries, Ltd.Dimethyl formamide: manufactured by Wako Pure Chemical Industries, Ltd. Special grade ・ 1,3-Dimethyl-2-imidazolidinone: Special grade manufactured by Wako Pure Chemical Industries, Ltd. ・ Tetrahydrofuran: Special grade manufactured by Wako Pure Chemical Industries, Ltd. ・ n-Hexane: Special grade manufactured by Wako Pure Chemical Industries, Ltd. ・Ethanol: 99.8% manufactured by Wako Pure Chemical Industries, Ltd.

[0022]

EXAMPLES (Example 1) Dimethyl sulfoxide 273.
49.4 g of cyclopentadiene in 5 g (3.5 mol)
(Purity 94.7%, 0.71 mol) and potassium hydroxide 38.5 g (purity 85%, 0.58 mol) were added, and the mixture was stirred at room temperature for 1.5 hours under a nitrogen stream to give a cyclopentadienyl potassium solution. I got The amount of dimethyl sulfoxide to cyclopentadienyl potassium was 6.0 in a molar ratio. While maintaining the temperature of the cyclopentadienyl potassium solution at 5 ° C., 143.3 g (1.2 mol) of isopropyl bromide was added dropwise over 50 minutes. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an isopropylcyclopentadiene-containing n-hexane solution. When the n-hexane solution was analyzed by gas chromatography, the yield of isopropylcyclopentadiene was 94.7% (0.55 mol).
l). Since the present embodiment satisfies the essential requirements of the present invention, it is a simple operation that does not require extreme non-aqueous conditions,
In addition, alkylcyclopentadiene is obtained in extremely high yield using an inexpensive reagent called potassium hydroxide.

Example 2 Dimethyl sulfoxide 21
To 3.7 g (2.7 mol) of cyclopentadiene 75.
1 g (purity 94.5%, 1.07 mol) and potassium hydroxide 59.2 g (purity 85%, 0.90 mol) were added, and the mixture was stirred at room temperature for 1.5 hours under a nitrogen stream to obtain cyclopentadienyl potassium. A solution was obtained. The amount of dimethyl sulfoxide to cyclopentadienyl potassium was 3.0 in a molar ratio. While maintaining the temperature of the cyclopentadienyl potassium solution at 5 ° C., 220.7 g (1.8 mol) of isopropyl bromide was added dropwise over 80 minutes. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an isopropylcyclopentadiene-containing n-hexane solution. When the n-hexane solution was analyzed by gas chromatography, the yield of isopropylcyclopentadiene was 99.0% (0.8%).
9 mol). Since this example satisfies the essential requirements of the present invention, it is a simple operation that does not require extreme non-aqueous conditions, and uses an inexpensive reagent called potassium hydroxide,
Alkylcyclopentadiene is obtained in very high yield.

Example 3 Dimethylformamide 26
To 4.4 g (3.6 mol) of cyclopentadiene 50.
2 g (purity 96.0%, 0.73 mol) and potassium hydroxide 39.6 g (purity 85%, 0.60 mol) were added, and the mixture was stirred at room temperature under a nitrogen stream for 3 hours to obtain a cyclopentadienyl potassium solution. Obtained. The amount of dimethylformamide to potassium cyclopentadienyl was 6.0 in molar ratio. While maintaining the temperature of the cyclopentadienyl potassium solution at 5 ° C., 147.6 g (1.2 mol) of isopropyl bromide was added dropwise over 60 minutes. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an isopropylcyclopentadiene-containing n-hexane solution. When the n-hexane solution was analyzed by gas chromatography, the yield of isopropylcyclopentadiene was 88.6% (0.532%).
mol). Since the present example satisfies the essential requirements of the present invention, alkylcyclopentadiene can be obtained in a high yield by a simple operation that does not require extreme non-aqueous conditions, and using an inexpensive reagent called potassium hydroxide. Have been obtained.

Example 4 50.9 g (purity: 96.0%, 0.74 mol) of cyclopentadiene was added to 410.9 g (3.6 mol) of 1,3-dimethyl-2-imidazolidinone.
l), potassium hydroxide 39.7 g (purity 85%, 0.6
0 mol), and the mixture was stirred at room temperature for 3 hours under a nitrogen stream to obtain a cyclopentadienyl potassium solution. The amount of 1,3-dimethyl-2-imidazolidinone relative to cyclopentadienyl potassium was 6.0 in a molar ratio. While keeping the temperature of the cyclopentadienyl potassium solution at 5 ° C, isopropyl bromide 147.5
g (1.2 mol) was added dropwise over 60 minutes. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an isopropylcyclopentadiene-containing n-hexane solution. When the n-hexane solution was analyzed by gas chromatography, the yield of isopropylcyclopentadiene was 85.4% (0.512 mol). Since the present example satisfies the essential requirements of the present invention, alkylcyclopentadiene can be obtained in a high yield by a simple operation that does not require extreme non-aqueous conditions, and using an inexpensive reagent called potassium hydroxide. Have been obtained.

Example 5 Dimethyl sulfoxide 28
To 1.2 g (3.6 mol) of cyclopentadiene
4 g (purity 95.12%, 0.71 mol) and potassium hydroxide 39.6 g (purity 85%, 0.60 mol) were added, and the mixture was stirred at room temperature under a nitrogen stream for 1.5 hours to give potassium cyclopentadienyl potassium. A solution was obtained. The amount of dimethyl sulfoxide to cyclopentadienyl potassium was 6.0 in a molar ratio. While maintaining the temperature of the cyclopentadienyl potassium solution at 30 ° C., 147.4 g (1.2 mol) of isopropyl bromide was added dropwise over 50 minutes. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an n-hexane solution containing isopropylcyclopentadiene. When the n-hexane solution was analyzed by gas chromatography, the yield of isopropylcyclopentadiene was 92.2%.
(0.553 mol). Since this example satisfies the essential requirements of the present invention, it is a simple operation that does not require extreme non-aqueous conditions, and uses an inexpensive reagent such as potassium hydroxide to produce alkylcyclopentadiene in extremely high yield. Has been obtained.

Example 6 Dimethyl sulfoxide 56
2.9 g (7.205 mol) of cyclopentadiene 9
8.6 g (purity 96.82%, 1.444 mol), potassium hydroxide 68.7 g (purity 49%, 0.600 mo)
l) was added, and the mixture was stirred at room temperature for 1.5 hours under a nitrogen stream to obtain a cyclopentadienyl potassium solution.
The amount of dimethyl sulfoxide to cyclopentadienyl potassium was 12.0 in molar ratio. While maintaining the temperature of the cyclopentadienyl potassium solution at 5 ° C., 147.8 g of isopropyl bromide (1.202 mol
l) was added dropwise over 50 minutes. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an n-hexane solution containing isopropylcyclopentadiene. When the n-hexane solution was analyzed by gas chromatography, the yield of isopropylcyclopentadiene was 93.9% (0.563 mol). Since this example satisfies the essential requirements of the present invention, it is a simple operation that does not require extreme non-aqueous conditions, and uses an inexpensive reagent such as potassium hydroxide to produce alkylcyclopentadiene in extremely high yield. Has been obtained.

Example 7 Dimethyl sulfoxide 28
To 1.4 g (3.602 mol) of cyclopentadiene 4
9.8 g (purity 95.74%, 0.721 mol), potassium hydroxide 39.66 g (purity 85%, 0.601 m)
ol) and stirred at room temperature for 1.5 hours under a nitrogen stream to obtain a cyclopentadienyl potassium solution. The amount of dimethyl sulfoxide to cyclopentadienyl potassium was 6.0 in a molar ratio. While maintaining the temperature of the cyclopentadienyl potassium solution at 5 ° C,
88.78 g of n-propyl bromide (0.722 mo
l) was added dropwise over 50 minutes. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an n-hexane solution containing ethylcyclopentadiene. The n
When the -hexane solution was analyzed by gas chromatography, the yield of n-propylcyclopentadiene was 92.
It was 1% (0.554 mol). Since this example satisfies the essential requirements of the present invention, it is a simple operation that does not require extreme non-aqueous conditions, and uses an inexpensive reagent such as potassium hydroxide to produce alkylcyclopentadiene in extremely high yield. Has been obtained.

Example 8 Dimethyl sulfoxide 23
4.9 g (3.01 mol) of cyclopentadiene 4
1.3 g (purity 95.74%, 0.598 mol), potassium hydroxide 33.07 g (purity 85%, 0.501 m)
ol) and stirred at room temperature for 1.5 hours under a nitrogen stream to obtain a cyclopentadienyl potassium solution. The amount of dimethyl sulfoxide to cyclopentadienyl potassium was 6.0 in a molar ratio. While maintaining the temperature of the cyclopentadienyl potassium solution at 5 ° C,
65.59 g (0.602 mol) of ethyl bromide was added dropwise over 50 minutes. After dropping, 1N hydrochloric acid and n
After the addition of -hexane, the organic layer was separated to obtain an n-hexane solution containing ethylcyclopentadiene. When the n-hexane solution was analyzed by gas chromatography,
The yield of ethylcyclopentadiene was 92.9% (0.4%).
65 mol). Since this example satisfies the essential requirements of the present invention, it is a simple operation that does not require extreme non-aqueous conditions, and uses an inexpensive reagent such as potassium hydroxide to produce alkylcyclopentadiene in extremely high yield. Has been obtained.

Example 9 Dimethyl sulfoxide 28
77.89 g (0.720 mol) of isopropylcyclopentadiene and 39.61 (purity 85%, 0.60 mol) of potassium hydroxide are added to 1.27 g (3.6 mol), and the mixture is stirred at room temperature for 2 hours under a nitrogen stream. Thus, a solution of potassium isopropylcyclopentadienyl was obtained.
The amount of dimethyl sulfoxide to isopropylcyclopentadienyl potassium was 6.0 in a molar ratio. While maintaining the temperature of the isopropylcyclopentadienyl potassium solution at 30 ° C, isopropyl bromide 14
7.59 g (1.2 mol) was added dropwise over 50 minutes.
After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain a diisopropylcyclopentadiene-containing n-hexane solution. When the n-hexane solution was analyzed by gas chromatography, the yield of diisopropylcyclopentadiene was 82.4% (0.494 mol).
l). Since the present embodiment satisfies the essential requirements of the present invention, it is a simple operation that does not require extreme non-aqueous conditions,
In addition, using an inexpensive reagent called potassium hydroxide, alkylcyclopentadiene is obtained in high yield.

Comparative Example 1 151.4 g of acetonitrile
(3.99 mol) 15.9 g of cyclopentadiene
(Purity 96.1%, 0.23 mol) and potassium hydroxide 12.5 g (purity 85%, 0.19 mol) were added, and the mixture was stirred at room temperature for 3.5 hours under a nitrogen stream, and further stirred at 55 ° C for 2 hours.
By heating for an hour, a cyclopentadienyl potassium solution was obtained. The amount of acetonitrile to potassium cyclopentadienyl was 19.4 in molar ratio. To 47.5 g (0.39 mol) of isopropyl bromide,
While maintaining the liquid temperature at 5 ° C., the above cyclopentadienyl potassium solution was added dropwise over 120 minutes. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an isopropylcyclopentadiene-containing n-hexane solution. When the n-hexane solution was analyzed by gas chromatography, the yield of isopropylcyclopentadiene was 47.0% (0.089 mol). In this comparative example, since the solvent of the present invention was not used, the yield of alkylcyclopentadiene was extremely low.

Comparative Example 2 Tetrahydrofuran 180.
To 3 g (2.50 mol) of cyclopentadiene 19.0
8 g (purity 96.1%, 0.28 mol) and potassium hydroxide 14.92 g (purity 85%, 0.23 mol) were added, and the mixture was stirred under a nitrogen stream at room temperature for 2 hours, but completely formed cyclopentadienyl potassium. Did not. Then 45 ° C
After heating for 1 hour at 65 ° C. for 1 hour, insolubles were generated. After filtration, the filtrate was analyzed. As a result, only 0.4% of potassium cyclopentadienyl was formed based on KOH used. KO used above
The amount of tetrahydrofuran to H was 10.9 in molar ratio.
Met. 56.6 g of isopropyl bromide (0.4 g)
6 mol), and the above filtrate was added dropwise over 60 minutes while maintaining the liquid temperature at 5 ° C. After completion of the dropwise addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated to obtain an n-hexane solution. When the n-hexane solution was analyzed by gas chromatography, no isopropylcyclopentadiene was generated. In this comparative example, since the solvent of the present invention was not used, no alkylcyclopentadiene was obtained at all.

(Comparative Example 3) 96.0 g of n-hexane
(1.1 mol) to cyclopentadiene 15.1 g (purity 96.1%, 0.22 mol), potassium hydroxide 1
2.5 g (purity: 85%, 0.19 mol) was added, and the mixture was stirred at room temperature under a nitrogen stream for 3 hours, but no cyclopentadienyl potassium was generated. In this comparative example, since the solvent of the present invention was not used, no alkylcyclopentadiene was obtained at all.

Comparative Example 4 52.0 g of ethanol (1.
15.6 g of cyclopentadiene (purity 9)
6.1%, 0.23 mol), potassium hydroxide 12.5
g (purity: 85%, 0.19 mol) was added, and the mixture was stirred at room temperature for 3 hours under a nitrogen stream to obtain a potassium cyclopentadienyl solution. The amount of ethanol relative to cyclopentadienyl potassium was 6.0 in a molar ratio. Isopropyl bromide was added to the above cyclopentadienyl potassium solution while maintaining the solution temperature at 5 ° C.
0 g (0.38 mol) was added dropwise over 120 minutes. After the addition, 1N hydrochloric acid and n-hexane were added, and the organic layer was separated. When the organic layer was analyzed by gas chromatography, no isopropylcyclopentadiene was generated. In this comparative example, since the solvent of the present invention was not used, no alkylcyclopentadiene was obtained at all.

[0035]

Industrial Applicability According to the present invention, an alkylcyclopentadiene compound useful as a synthetic precursor of a fine chemical intermediate, a pharmaceutical and agricultural chemical intermediate, or a olefin polymerization catalyst such as a metallocene catalyst is extremely inhibited. The production can be performed by a simple operation that does not require water conditions and using an inexpensive reagent.

Claims (3)

[Claims] A cyclopentadiene compound represented by the general formula R-
X (R is an unsubstituted or substituted aliphatic hydrocarbon group,
X is a halogen, a tosyl group, or an alkylsulfonate group). A method for producing an alkylcyclopentadiene compound from an alkylating agent, comprising the following two steps: (I) A step of preparing a cyclopentadienyl metal from cyclopentadiene and a metal hydroxide (cyclopentadienyl metal preparation step). (II) The cyclopentadienyl metal and the alkylating agent are present in the presence of at least one solvent selected from the group consisting of dimethyl sulfoxide, N, N-dimethylformamide and 1,3-dimethyl-2-imidazolidinone A step of reacting below to obtain an alkylcyclopentadiene compound (alkylation step). 2. The method for producing an alkylcyclopentadiene compound according to claim 1, wherein the metal hydroxide is potassium hydroxide in the cyclopentadienyl metal preparation step. 3. The process for producing an alkylcyclopentadiene compound according to claim 1, wherein the step of preparing a cyclopentadienyl metal and the step of alkylating are performed in an inert gas atmosphere.