JP2015044754A - Method of producing 3-ethoxy-2-tert-butyl alkyl propionate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel production method of 3-ethoxy-2-tert-butyl alkyl propionate used for the production of an olefin polymerization solid catalyst.SOLUTION: A 2-ethoxy methyl malonic acid diester derivative represented by formula (1) (where Rand Rrepresent a 1-4C alkyl group) is reacted in the presence of a base.

Description

  The present invention relates to a novel method for producing alkyl 3-ethoxy-2-tert-butylpropionate used for the production of a solid catalyst for olefin polymerization.

  Alkyl 3-ethoxy-2-tert-butylpropionate is used for producing a solid catalyst for olefin polymerization which exhibits sufficiently high polymerization activity and gives a polymer having a low molecular weight component and a low content of indefinite components. A compound known as an internal electron donor. However, there is no known document describing an industrial production method of this alkyl 3-ethoxy-2-tert-butylpropionate. For example, referring to the description of Non-Patent Document 1, An ester enolate is generated from a strong base such as lithium diisopropylamide or lithium 1,1,1,3,3,3-hexamethyldisilazide, and then reacted with halogenated methyl ethyl ether. A method for producing alkyl ethoxy-2-tert-butylpropionate is conceivable.

However, the above method uses an expensive base that is inferior in availability, and it is necessary to carry out the reaction at a low temperature of about -78 ° C. in order to suppress the self-condensation reaction of alkyl tert-butyl acetate as a raw material. It cannot be said that it is an industrially advantageous production method, and development of an industrial production method for alkyl 3-ethoxy-2-tert-butylpropionate has been desired.

JP 2013-082812 A

Laboratory Chemistry Lecture 5th Edition, Volume 16 “Synthesis of Organic Compounds IV”, p. 49 (2005), Maruzen Publishing Co., Ltd.

The object of the present invention is to obtain an alkyl 3-ethoxy-2-tert-butylpropionate used in the production of a solid catalyst for olefin polymerization from a generally available raw material and which requires a special cooling device. An object of the present invention is to provide a production method which does not require a low temperature condition such as 78 ° C.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained the following formula (3)

（式中Ｒ_１、Ｒ_２は炭素数１〜４のアルキル基を表し、同一であっても異なっていても良い。）
で表される化合物とハロゲン化メチルエチルエーテルとを特定条件で反応させて得られる以下式（１）

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
The following formula (1) obtained by reacting a compound represented by the formula with halogenated methyl ethyl ether under specific conditions:

（式中Ｒ_１、Ｒ_２は炭素数１〜４のアルキル基を表し、同一であっても異なっていても良い。）
で表される新規化合物を、アルカリ金属アルコキシド及びアルカリ金属水酸化物からなる群から選ばれる少なくとも１種の塩基の存在下で反応させることにより、３−エトキシ−２−ｔｅｒｔ−ブチルプロピオン酸アルキルを製造できることを見出した。具体的には以下の発明を含む。

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
Is reacted in the presence of at least one base selected from the group consisting of alkali metal alkoxides and alkali metal hydroxides to produce alkyl 3-ethoxy-2-tert-butylpropionate. We found that it can be manufactured. Specifically, the following invention is included.

<1>
Following formula (1)

（式中Ｒ_１、Ｒ_２は炭素数１〜４のアルキル基を表し、同一であっても異なっていても良い。）
で表される化合物をアルカリ金属アルコキシド及びアルカリ金属水酸化物からなる群から選ばれる少なくとも１種の塩基の存在下で反応させることを特徴とする以下式（２）

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
Wherein the compound represented by formula (2) is reacted in the presence of at least one base selected from the group consisting of alkali metal alkoxides and alkali metal hydroxides:

（式中Ｒ_３は炭素数１〜４のアルキル基を表す。）
で表される３−エトキシ−２−ｔｅｒｔ−ブチルプロピオン酸アルキルの製造方法。

(In the formula, R ₃ represents an alkyl group having 1 to 4 carbon atoms.)
The manufacturing method of 3-ethoxy- 2-tert- butyl alkyl propionate represented by these.

<2>
Following formula (1)

（式中Ｒ_１、Ｒ_２は炭素数１〜４のアルキル基を表し、同一であっても異なっていても良い。）
で表される化合物。

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
A compound represented by

<3>
In the presence of dimethylacetamide and sodium hydride, the following formula (3)

（式中Ｒ_１、Ｒ_２は炭素数１〜４のアルキル基を表し、同一であっても異なっていても良い。）
で表される化合物とハロゲン化メチルエチルエーテルとを反応させることを特徴とする＜１＞記載の化合物の製造方法。

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
<1> The method for producing a compound according to <1>, wherein the compound represented by formula (1) is reacted with halogenated methyl ethyl ether.

According to the present invention, an alkyl 3-ethoxy-2-tert-butylpropionate can be produced from a generally available raw material and does not require low temperature conditions, and at the same time, a novel compound used in the present method Can be manufactured.

  Hereinafter, the present invention will be described together with embodiments thereof.

  Formula (1) below

（式中Ｒ_１、Ｒ_２は炭素数１〜４のアルキル基を表し、同一であっても異なっていても良い。）
で表される化合物（以下、２−エトキシメチルマロン酸ジエステル誘導体と称することがある）は、オレフィン重合用固体触媒の製造に用いられる３−エトキシ−２−ｔｅｒｔ−ブチルプロピオン酸アルキルを製造するための、新規な化合物である。この２−エトキシメチルマロン酸ジエステル誘導体のアルキル基であるＲ_１及びＲ_２は炭素数１〜４のアルキル基である必要がある。本化合物は後述する方法で製造されるが、その際の原料であるマロン酸ジエステルの入手性から、Ｒ_１とＲ_２は同一であることが好ましい。また、後述する本化合物から３−エトキシ−２−ｔｅｒｔ−ブチルプロピオン酸アルキルを製造する際の反応性から、Ｒ_１及びＲ_２はメチル基またはエチル基であることが好ましく、更にＲ_１及びＲ_２がメチル基であることがより好ましい。

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
In order to produce alkyl 3-ethoxy-2-tert-butylpropionate used for the production of a solid catalyst for olefin polymerization, a compound represented by the formula (hereinafter sometimes referred to as 2-ethoxymethylmalonic acid diester derivative) These are novel compounds. R ₁ and R ₂ which are alkyl groups of the 2-ethoxymethylmalonic acid diester derivative need to be alkyl groups having 1 to 4 carbon atoms. The compounds are produced by a method described later, from the availability of malonic acid diester as a raw material of the case, it is preferred that R ₁ and R ₂ are the same. Moreover, from the reactivity at the time of manufacturing alkyl 3-ethoxy-2-tert-butylpropionate from this compound described later, R ₁ and R ₂ are preferably a methyl group or an ethyl group, and further R ₁ and R More preferably, ₂ is a methyl group.

Then, the manufacturing method of 2-ethoxymethylmalonic acid diester derivative represented by the said Formula (1) is explained in full detail. 2-Ethoxymethylmalonic acid diester derivative is represented by the following formula (3) in the presence of dimethylacetamide and sodium hydride.

（式中Ｒ_１、Ｒ_２は炭素数１〜４のアルキル基を表し、同一であっても異なっていても良い。）
で表される化合物とハロゲン化メチルエチルエーテルとを反応させることによって製造される。上記式（３）で表される化合物は、ルイス酸存在下、対応するアルキル基を有するマロン酸ジエステルとｔｅｒｔ−ブチルクロライドを反応させることにより容易に製造することが可能である。

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
It is manufactured by making the halogenated methyl ethyl ether react. The compound represented by the above formula (3) can be easily produced by reacting a malonic acid diester having a corresponding alkyl group with tert-butyl chloride in the presence of a Lewis acid.

In carrying out the above reaction, it is generally known to carry out the reaction using a base as a catalyst in the presence of a solvent. At this time, it is generally known that dimethylformamide, dimethylacetamide, tetrahydrofuran or the like can be used as a solvent, and the base is generally an alkali metal hydroxide or sodium hydroxide or potassium hydroxide. It is known that alkali metal hydrides such as sodium hydride and potassium hydride, and alkali metal alcohol salts such as sodium methoxide and potassium ethoxide can be used. However, in this reaction, the reaction proceeds specifically and favorably only when dimethylacetamide is used as the solvent and sodium hydride is used as the base. The amount of these solvents and bases used is not particularly limited, but the amount of dimethylacetamide used is usually 1 to 20 times by weight, preferably 5 to 11 times by weight based on 1 part by weight of the compound represented by formula (3). use. Further, sodium hydride is used in an amount of 1 to 4 times mol, preferably 1 to 2 times mol for 1 mol of the compound represented by formula (3). If the amount of dimethylacedoamide used is more than 20 times, the reaction is not inhibited, but it is economically undesirable, and if it is small, stirring inhibition may occur. When the amount of sodium hydride used is more than 4 times, excess base may make post-treatment after the reaction complicated, and when it is less than 1 time, the reaction may not be achieved.

Examples of the halogen atom of the halogenated methyl ethyl ether used in the above reaction include chlorine, bromine and iodine atoms. From the viewpoint of availability, chlorine and bromine atoms are preferable, and chlorine atom is more preferable. Moreover, the usage-amount of halogenated methyl ethyl ether is although it does not specifically limit, Usually, 1-4 times mole is used with respect to 1 mol of compounds represented by Formula (3), Preferably it is used 1-2 times mole. If it is more than 2 times, the expensive halide remains unreacted, which is economically undesirable. If it is less than 1 time, the reaction may not be achieved.

The above reaction is usually obtained by adding halogenated methyl ethyl ether to a compound represented by the formula (3) and a base catalyst in a solvent and reacting at 10 to 40 ° C. for 1 to 24 hours. The obtained 2-ethoxymethylmalonic acid diester derivative can be taken out by a conventional method such as extraction with an organic solvent after neutralization, but without being taken out, 3-ethoxy-2-tert-butylpropionic acid described later is used. It can also be used for the production of alkyl.

Subsequently, 3-ethoxy-2-tert-butyl is reacted with the 2-ethoxymethylmalonic acid diester derivative in the presence of at least one base selected from the group consisting of alkali metal alkoxides and alkali metal hydroxides. The step of obtaining alkyl propionate will be described in detail.

In this reaction, one ester group of 2-ethoxymethylmalonic acid diester is hydrolyzed and then the hydrolyzed carboxylic acid moiety is decarboxylated to obtain the desired alkyl 3-ethoxy-2-tert-butylpropionate. Is.

Examples of the alkali metal alkoxide used in this reaction include sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, and potassium tert-butoxide. These alkali metal alkoxides may be solid or alcohol solutions. In the case of an alcohol solution, the alkali metal alkoxide concentration is preferably 5% or more. Moreover, sodium hydroxide and potassium hydroxide are illustrated as an alkali metal hydroxide used by this reaction. The alkali metal hydroxide may be solid or an aqueous solution, but the concentration of the alkali metal hydroxide in the aqueous solution is preferably 6% by weight or more. Among these listed alkali metal alkoxides and alkali metal hydroxides, although this reaction includes an ester group hydrolysis step, solid (not aqueous solution) sodium hydroxide or potassium hydroxide suppresses by-products. It is preferable from the viewpoint.

The alkali metal alkoxides and alkali metal hydroxides listed above may be used alone or in combination of two or more as required. These are used in an amount of usually 1 to 10 moles, preferably 5 to 10 moles per mole of 2-ethoxymethylmalonic acid diester derivative. If it is less than 1 time, the reaction may not be achieved.

This reaction is usually carried out in the presence of an alcohol having 1 to 4 carbon atoms, specifically methanol, ethanol, propanol, butanol or the like. Of these solvents, methanol and ethanol are preferred. The amount of these solvents to be used is usually 5 to 30 times, preferably 10 to 20 times, based on 1 weight times of 2-ethoxymethylmalonic acid diester derivative.

In this reaction, a 2-ethoxymethylmalonic acid diester derivative and a base are mixed in a solvent and then reacted at 50 to 120 ° C., preferably 70 to 90 ° C. for 1 to 96 hours, to thereby obtain the desired 3-ethoxy-2-tert. -Alkyl butylpropionate can be obtained. The alkyl 3-ethoxy-2-tert-butylpropionate thus obtained can be purified by a conventional method such as distillation and used for production of a solid catalyst for olefin polymerization.

In addition, the alkyl 3-ethoxy-2-tert-butylpropionate represented by the above formula (2) obtained by this reaction may be converted into 3-ethoxy-2-tert depending on the 2-ethoxymethylmalonic acid diester and the solvent to be used. -A mixture of alkyl 3-ethoxy-2-tert-butylpropionates in which the alkyl group (R ₃ ) of the alkyl butylpropionate is not single but has different alkyl groups (eg 3-ethoxy-2-tert-butylpropionic acid) A mixture of methyl and ethyl 3-ethoxy-2-tert-butylpropionate). Even these mixtures can be suitably used as a solid catalyst for olefin polymerization. However, when a desired alkyl 3-ethoxy-2-tert-butylpropionate having an alkyl group is desired, After obtaining an alkyl-2-tert-butylpropionate alkyl mixture, it can be converted to an alkyl 3-ethoxy-2-tert-butylpropionate having a desired alkyl group by applying a known transesterification reaction or the like. Is possible.

Examples of the present invention are shown below, but the present invention is not limited thereto.

[1] In the GC purity examples, the purity, the production rate of each compound, and the remaining amount of each raw material are area percentage values measured under the following conditions using gas chromatography.
Gas chromatography measurement conditions:
Equipment used: Gas chromatograph GC-2010 manufactured by Shimadzu Corporation
Column: Capillary column DB-5: Inner diameter 0.25 mm × length 30 m × membrane pressure 0.25 μm
max. temp. 325 ° C
Column temperature: 50 ° C → 300 ° C
Vaporization chamber temperature: 250 ° C
Detector temperature: 300 ° C
Detector: FID
Carrier: N ₂ (40 ml / min)
Combustion gas: Hydrogen (40 ml / min), Air (400 ml / min)
Injection volume: 5 μL

[2] NMR
¹ H-NMR and ¹³ C-NMR were recorded by JEOL-ESC400 using tetramethylsilane as internal standard and CDCl ₃ as solvent.

[1] Production example of compound represented by formula (3)

<Reference Example 1>
In a 300 ml glass reaction vessel equipped with a stirrer, cooler and thermometer, 20 g of malonic acid dimethyl ester is heated to 50-60 ° C., and 70 g of t-butyl chloride and 40 g of boron trifluoride diethyl ether complex catalyst are added. The mixture was kept warm for 7.5 hours until the disappearance of the raw materials was confirmed.
After stirring while warming, 200 g of 1N hydrochloric acid was added to quench the unreacted catalyst, and 100 g of toluene was added to extract the target product into the oil layer. Next, neutralize with 200 g of 1N caustic water, repeat washing with water, and then distill off the solvent under reduced pressure (4)

で表される化合物１２．２ｇ（収率４３％）を得た。

12.2 g (43% yield) of the compound represented by

<Reference Example 2>
The same procedure as in Reference Example 1 was conducted except that malonic acid diethyl ester was used instead of malonic acid dimethyl ester, and the following formula (5)

で表される化合物４．８ｇ（収率７０％）を得た。

4.8 g (yield 70%) of the compound represented by the formula:

[2] Production example of 2-ethoxymethylmalonic acid diester

<Example 1>
Into a 300 ml glass reaction vessel equipped with a stirrer, a cooler and a thermometer was charged 12.2 g of the compound represented by the formula (4) obtained in Reference Example 1, 3.12 g of sodium hydride, and 120 g of dimethylacetamide. did. After mixing at 25 ° C. for 1 hour, the mixture was cooled to 5 ° C., 7.4 g of ethoxymethyl chloride was added dropwise at 0 to 10 ° C. in 30 minutes, and after raising the temperature to 25 ° C., about 1 until the raw material disappeared at that temperature. Stir for hours.
After the reaction, the reaction mixture was neutralized with 120 g of 1N hydrochloric acid, and then 50 g of toluene was added to extract the target product into the organic layer. Next, the mixture was neutralized with 120 g of 1N caustic water, washed repeatedly with water, and then the solvent was distilled off under reduced pressure to obtain the following formula (6).

で表される２−エトキシメチルマロン酸ジエステル誘導体８．１ｇ（収率５１％）を得た。上記式（６）で表される２−エトキシメチルマロン酸ジエステル誘導体の^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲの分析値はそれぞれ次のとおりである。

In this way, 8.1 g (yield 51%) of 2-ethoxymethylmalonic acid diester derivative represented by the formula: Analytical values of ¹ H-NMR and ¹³ C-NMR of the 2-ethoxymethylmalonic acid diester derivative represented by the above formula (6) are as follows.

¹ H-NMR (400 MHz, δ value (ppm, TMS standard), CDCl ₃ )
3.87 (s, 2H), 3.71 (s, 6H), 3.48-3.43 (q, J = 6.8 Hz, 2H), 1.15-1.11 (m, 12H),
¹³ C-NMR (100 MHz, δ value (ppm, CDCl ₃ standard), CDCl ₃ )
170.3, 70.8, 66.9, 51.8, 27.7, 14.9

<Example 2>
To a glass test tube, 0.5 g of the compound represented by the formula (5) obtained in the stirrer and Reference Example 2, 0.11 g of sodium hydride, and 5 g of dimethylacetamide were added at 25 ° C., and the same temperature was maintained for 1 hour. After mixing, the mixture was cooled to 5 ° C and 0.26 g of ethoxymethyl chloride was added dropwise at 0 to 5 ° C. Thereafter, the temperature was raised to 25 ° C., and the mixture was stirred for about 1 hour until the raw material disappeared at the same temperature. After the reaction, the mixture was neutralized with 10 g of 1N hydrochloric acid, and the target product was extracted into the organic layer with 10 g of toluene. Next, after neutralizing with 10 g of 1N caustic water, washing with water was repeated, and the solvent was distilled off under reduced pressure to obtain the following formula (7).

で表される化合物０．４６ｇ（収率７３％）を得た。式（７）で表される２−エトキシメチルマロン酸ジエステル誘導体の^１Ｈ−ＮＭＲ及び^１３Ｃ−ＮＭＲの分析値はそれぞれ次のとおりである。

0.46 g (yield 73%) of the compound represented by Analytical values of ¹ H-NMR and ¹³ C-NMR of the 2-ethoxymethylmalonic acid diester derivative represented by the formula (7) are as follows.

¹ H-NMR (400 MHz, δ value (ppm, TMS standard), CDCl ₃ )
4.21-4.16 (q, J = 7.2 Hz, 4H), 3.87 (s, 2H), 3.48-3.43 (q, J = 6.4 Hz, 2H), 1.28 -1.24 (t, J = 7.6 Hz, 6H),
1.15 (s, 9H)
¹³ C-NMR (100 MHz, δ value (ppm, CDCl ₃ standard), CDCl ₃ )
169.8, 70.9, 66.9, 60.6, 35.8, 28.2, 27.8, 14.9, 14.1

<Comparative Example 1>
When the reaction was carried out in the same manner as in Example 2 except that sodium ethoxide was used as the base and ethanol was used as the solvent, the reaction did not proceed, and it was represented by the formula (5) obtained in Reference Example 2 as the raw material. The compound was recovered.

<Comparative example 2>
The reaction was carried out in the same manner as in Example 2 except that tetrahydrofuran was used as the solvent. As a result, the reaction did not proceed, and the compound represented by the formula (5) obtained in Reference Example 2 as a raw material was recovered.

<Comparative Example 3>
When the reaction was carried out in the same manner as in Example 2 except that dimethylformamide was used as the solvent, the side reaction proceeded and the target product was not obtained at all.

[3] Production example of alkyl 3-ethoxy-2-tert-butylpropionate

<Example 3>
In a 300 ml glass reaction vessel equipped with a stirrer, a condenser and a thermometer, 5 g of 2-ethoxymethylmalonic acid diester derivative (6) obtained in Example 1, 4.5 g of solid potassium hydroxide as a base, ethanol 50 g was added, the temperature was raised to 80 ° C., reacted for 6.5 hours while refluxing at 75 ° C. to 77 ° C., and the obtained reaction mass was analyzed using a gas chromatograph, 3-ethoxy-2- An alkyl tert-butylpropionate was obtained with a yield of 67%. The results are shown in Table 1.

<Examples 4 to 13><Comparative Examples 4 to 12>
As shown in Table 1, in the same manner as in Example 3, except that the 2-ethoxymethylmalonic acid diester derivative, base species or acid species, solvent species, reaction temperature, and reaction time were changed, 3-ethoxy-2-tert- Alkyl butylpropionate was prepared. The results are shown in Table 1.

In the following table, the alkyl group represents an alkyl group of the 2-ethoxymethylmalonic acid diester derivative (R ₁ and R ₂ in the above formula (1)), and the production rate is alkyl 3-ethoxy-2-tert-butylpropionate ( Each production | generation rate and total production | generation rate of R < ₃ > in the said Formula (2) are represented. In the base type column, (s) represents that the base is solid, BTEAH represents benzyltriethylammonium hydroxide, and PTS represents paratoluenesulfonic acid.

<Example 14> (Isolation of alkyl 3-ethoxy-2-tert-butylpropionate)
50 g of toluene was added to the reaction mass containing alkyl 3-ethoxy-2-tert-butylpropionate obtained in Example 3 to extract organic matter, washed with 30 g of 1N caustic, neutralized with 40 g of 1N hydrochloric acid, and washed with water. As a result of distilling off the solvent later, 2.3 g (yield 54%) of a mixture of ethyl 3-ethoxy-2-tert-butylpropionate and methyl 3-ethoxy-2-tert-butylpropionate was obtained.

Claims (3)

Following formula (1)

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different)
Wherein the compound represented by formula (2) is reacted in the presence of at least one base selected from the group consisting of alkali metal alkoxides and alkali metal hydroxides:

(In the formula, R ₃ represents an alkyl group having 1 to 4 carbon atoms.)
The manufacturing method of 3-ethoxy- 2-tert- butyl alkyl propionate represented by these. Following formula (1)

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
A compound represented by In the presence of dimethylacetamide and sodium hydride, the following formula (3)

(Wherein R ₁ and R ₂ represent an alkyl group having 1 to 4 carbon atoms, and may be the same or different.)
A method for producing a compound according to claim 2, wherein the compound represented by the formula (2) is reacted with halogenated methyl ethyl ether.