JP2011042677A - Method for producing phenylcyclohexene derivative or styrene derivative - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple, easy and inexpensive production method by improving bad yield in dehydration processes of benzyl alcohol derivatives used in production processes of liquid crystal materials. <P>SOLUTION: The derivatives expressed by general formula (2) or general formula (4) are produced by reacting bis(trichloromethyl) carbonate with the benzyl alcohol derivatives. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a phenylcyclohexene derivative or a styrene derivative.

  In producing various liquid crystal compounds, a method is generally used in which a benzyl alcohol derivative is dehydrated and the resulting double bond is catalytically reduced in the presence of a catalyst. An example is shown below. (See Patent Document 1)

The yield of the dehydration step in the above method is not as high as 64%. As a dehydrating agent that gives a high yield, there is a general example of thionyl chloride-pyridine. However, since the catalyst is poisoned by sulfur derived from thionyl chloride in the catalytic reduction step using the catalyst after the dehydration step, a desulfurization step is necessary. For these reasons, there has been a demand for a simple and inexpensive method for producing a phenylcyclohexene derivative or a styrene derivative that has a high yield and does not require purification.

EP-A-0331091 (pages 23 and 24) By J.S.Lomas, Tetrahedron Lett., 1971, p.599-602.

  The problem to be solved by the present invention is to provide a simple and inexpensive method for producing phenylcyclohexene derivatives or styrene derivatives.

As a result of intensive studies to solve the above problems, the present inventor has found that phenylcyclohexene derivatives or styrene derivatives can be obtained in high yield by allowing bis (trichloromethyl) carbonate to act on benzyl alcohol derivatives. It came to complete.
That is, the present invention relates to the general formula (1)

（式中、R²およびR³はそれぞれ独立的に主鎖炭素原子数1〜6のアルキル基またはR²およびR³は互いに連結して主鎖炭素原子数1〜7のアルキレン基を表し、これらの基中に存在する1個または2個以上の水素原子は炭素原子数1〜4のアルキル基で置換されてもよく、
L¹ 、L²、L³およびL⁴はそれぞれ独立的にフッ素原子、塩素原子または水素原子を表し、L⁵はフッ素原子、塩素原子、水素原子、炭素数1〜12のアルキル基または炭素数1〜12のアルコキシ基を表す。）で表されるベンジルアルコール誘導体に炭酸ビス（トリクロロメチル）を作用させることにより一般式（２）

(Wherein R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms in the main chain, or R ² and R ³ are connected to each other to represent an alkylene group having 1 to 7 carbon atoms in the main chain; One or more hydrogen atoms present in these groups may be substituted with an alkyl group having 1 to 4 carbon atoms,
L ¹ , L ² , L ³ and L ⁴ each independently represent a fluorine atom, a chlorine atom or a hydrogen atom, and L ⁵ is a fluorine atom, a chlorine atom, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a carbon number 1 to 12 alkoxy groups are represented. By reacting bis (trichloromethyl) carbonate with a benzyl alcohol derivative represented by the general formula (2)

（式中、R²、R³、L¹、L²、L³、L⁴およびL⁵は一般式(１)と同じ意味を表す。）で表されるフェニルシクロヘキセン誘導体の製造方法および、
一般式（３）

(Wherein R ² , R ³ , L ¹ , L ² , L ³ , L ⁴ and L ⁵ represent the same meaning as in general formula (1)), and a method for producing a phenylcyclohexene derivative represented by
General formula (3)

（式中、R²およびR³はそれぞれ独立的に主鎖炭素原子数1〜6のアルキル基またはR²およびR³は互いに連結して主鎖炭素原子数1〜7のアルキレン基を表し、これらの基中に存在する1個または2個以上の水素原子は炭素原子数1〜4のアルキル基で置換されてもよく、nは0、1または2を表し、L¹ 、L²、L³およびL⁴はそれぞれ独立的にフッ素原子、塩素原子または水素原子を表し、L⁵はフッ素原子、塩素原子、水素原子、炭素数1〜12のアルキル基または炭素数1〜12のアルコキシ基を表す。）で表されるベンジルアルコール誘導体に炭酸ビス（トリクロロメチル）を作用させることにより一般式（４）

(Wherein R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms in the main chain, or R ² and R ³ are connected to each other to represent an alkylene group having 1 to 7 carbon atoms in the main chain; One or more hydrogen atoms present in these groups may be substituted with an alkyl group having 1 to 4 carbon atoms, n represents 0, 1 or 2, and L ¹ , L ² , L ³ and L ⁴ each independently represent a fluorine atom, a chlorine atom or a hydrogen atom, and L ⁵ represents a fluorine atom, a chlorine atom, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. By reacting bis (trichloromethyl) carbonate with the benzyl alcohol derivative represented by the general formula (4)

（式中、R²、R³、L¹、L²、L³、L⁴、L⁵およびnは一般式(３)と同じ意味を表す。）で表されるスチレン誘導体の製造方法を提供することである。

(Wherein R ² , R ³ , L ¹ , L ² , L ³ , L ⁴ , L ⁵ and n represent the same meaning as in general formula (3)). It is to be.

  According to the present invention, a phenylcyclohexene derivative or a styrene derivative can be obtained in a high yield and does not require purification, so that it can be produced easily and inexpensively.

  In this production method, bis (trichloromethyl) carbonate can be used alone, but it is preferably used in the presence of a base such as pyridine, triethylamine or diethylamine, and particularly preferably used in the presence of pyridine.

  In this production method, it is preferable to use a solvent. As the solvent, the above-mentioned base can be used as a solvent, and aromatic compounds such as benzene, toluene, xylene, chlorobenzene, pentane, hexane, cyclohexane, heptane, octane. , Chlorinated carbonization of saturated hydrocarbons such as decahydronaphthalene, dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, etc. Hydrogen, diethyl ether, methyl-t-butyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, 1,4-dioxane and other ether solvents can be used alone or in combination, among which aromatic hydrocarbons or Chlorinated hydrocarbons are preferred, toluene, dichloromethane or 1,2-dichloroethane is particularly preferred.

The compounds represented by the general formula (1) and the general formula (2) include many compounds, but the following compounds are preferable.
In general formula (1), R ² and R ³ are alkyl groups having 1 to 6 main chain carbon atoms or R ² and R ³ are connected to each other to represent an alkylene group having 1 to 7 main chain carbon atoms. One or two or more hydrogen atoms present in the above group may be substituted with an alkyl group having 1 to 4 carbon atoms, preferably an alkylene group having 1 to 7 carbon atoms in the main chain, and an ethylene group or 1 1,3-propylene group is preferred, and ethylene group is more preferred.

L ¹ , L ² , L ³ and L ⁴ each independently represent a fluorine atom, a chlorine atom or a hydrogen atom, preferably a fluorine atom or a hydrogen atom. L ⁵ represents a fluorine atom, a chlorine atom, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, but a fluorine atom, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a carbon number 1-12 alkoxy groups are preferred.

In the general formula (2), R ² and R ³ are alkyl groups having 1 to 6 carbon atoms in the main chain or R ² and R ³ are connected to each other to represent an alkylene group having 1 to 7 carbon atoms in the main chain. One or two or more hydrogen atoms present in the above group may be substituted with an alkyl group having 1 to 4 carbon atoms, preferably an alkylene group having 1 to 7 carbon atoms in the main chain, and an ethylene group or 1 1,3-propylene group is preferred, and ethylene group is more preferred.

L ¹ , L ² , L ³ and L ⁴ each independently represent a fluorine atom, a chlorine atom or a hydrogen atom, preferably a fluorine atom or a hydrogen atom. L ⁵ represents a fluorine atom, a chlorine atom, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, but a fluorine atom, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a carbon number 1-12 alkoxy groups are preferred. n represents 0, 1 or 2, preferably 0 or 2, and more preferably 0.

EXAMPLES Hereinafter, although an Example is given and this invention is further explained in full detail, this invention is not limited to these Examples. The purity of the compound was confirmed by gas chromatography or the like.
Example 1 Synthesis of 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] -7-decene

1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] decan-8-ol (50.0 g) was dissolved in toluene (150 ml) and pyridine (44.0 g), and the internal temperature was cooled to 5 to 10 ° C. A solution prepared by dissolving 27.5 g of bis (trichloromethyl) carbonate in 110 ml of toluene was added dropwise to this solution over 30 minutes. The mixture was further stirred at 25 ° C for 1 hour, poured into 250 ml of water, and the organic layer was separated. The organic layer was washed twice with 250 ml of water and once with 250 ml of saturated saline, and dried by adding anhydrous sodium sulfate. Anhydrous sodium sulfate was filtered off, and the solvent was distilled off to obtain 46.2 g of 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] -7-decene almost quantitatively. When the purity of the obtained compound was measured by gas chromatography, it was as high as 98.0%.
¹ H-NMR (400 MHz, CDCl ₃ ) δ / ppm 1.92 (t, 2 H), 2.46-2.48 (m, 2 H), 2.61-2.66 (m, 2 H), 4.02 (s, 4 H), 6.01-6.04 (m, 1 H), 6.89-6.93 (m, 1 H), 7.06-7.09 (m, 1 H), 7.15-7.17 (m, 1 H), 7.22-7.28 (m, 1 H)

In order to confirm whether the obtained compound does not cause a problem in the subsequent catalytic reduction step, the obtained 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] -7- When 46.2 g of decene was dissolved in 230 ml of toluene, 4.6 g of 5% palladium carbon was added and stirred at a hydrogen pressure of 0.4 MPa, the reaction was completed in 3 hours, and 1,4-dioxa-8- (3-fluoro Phenyl) -spiro [4,5] -7-decane was obtained.
Comparative Example 1 Synthesis of 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] -7-decene (method using an acid catalyst)

Dissolve 50.0 g of 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] decan-8-ol in 200 ml of toluene, add 2.0 g of potassium hydrogen sulfate, and remove azeotropic water. Heated to reflux for 6 hours. The mixture was allowed to cool to room temperature, washed successively with 200 ml of saturated aqueous sodium hydrogen carbonate, 200 ml of water and 200 ml of saturated brine, and dried over anhydrous sodium sulfate. Anhydrous sodium sulfate was filtered off and the solvent was distilled off to obtain 46.4 g of 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] -7-decene. When the purity of the obtained compound was measured by gas chromatography, it was as low as 85.1%.
Comparative Example 2 Synthesis of 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] -7-decene (method using a dehydrating agent)

  5,0.0 g of 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] decan-8-ol was dissolved in 150 ml of pyridine, and the internal temperature was cooled to 5 to 10 ° C. To this solution, 26.6 g of thionyl chloride was added dropwise over 30 minutes with stirring. The mixture was further stirred at 25 ° C. for 1 hour, poured into 150 ml of water, extracted with 250 ml of toluene, and the organic layer was separated. The organic layer was washed twice with 250 ml of water and once with 250 ml of saturated saline, and dried by adding anhydrous sodium sulfate. Anhydrous sodium sulfate was removed by filtration, and the solvent was distilled off to obtain 41.3 g of 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] -7-decene. It did not reach Example 1. When the purity of the obtained compound was measured by gas chromatography, it was 92.2% and a relatively high purity.

  In order to confirm whether the obtained compound does not cause a problem in the subsequent catalytic reduction step, the obtained 1,4-dioxa-8- (3-fluorophenyl) -spiro [4,5] -7- When 41.3 g of decene was dissolved in 220 ml of toluene, 4.1 g of 5% palladium carbon was added and stirred at a hydrogen pressure of 0.4 MPa, the catalytic reduction reaction did not proceed even after 6 hours.

  The present invention is very useful as a method for producing an intermediate of a liquid crystal compound.

Claims (6)

General formula (1)

(Wherein R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms in the main chain, or R ² and R ³ are connected to each other to represent an alkylene group having 1 to 7 carbon atoms in the main chain; One or more hydrogen atoms present in these groups may be substituted with an alkyl group having 1 to 4 carbon atoms,
L ¹ , L ² , L ³ and L ⁴ each independently represent a fluorine atom, a chlorine atom or a hydrogen atom, and L ⁵ is a fluorine atom, a chlorine atom, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a carbon number 1 to 12 alkoxy groups are represented. By reacting bis (trichloromethyl) carbonate with a benzyl alcohol derivative represented by the general formula (2)

(Wherein R ² , R ³ , L ¹ , L ² , L ³ , L ⁴ and L ⁵ represent the same meaning as in general formula (1)). General formula (3)

(Wherein R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms in the main chain, or R ² and R ³ are connected to each other to represent an alkylene group having 1 to 7 carbon atoms in the main chain; One or more hydrogen atoms present in these groups may be substituted with an alkyl group having 1 to 4 carbon atoms, n represents 0, 1 or 2, and L ¹ , L ² , L ³ and L ⁴ each independently represent a fluorine atom, a chlorine atom or a hydrogen atom, and L ⁵ represents a fluorine atom, a chlorine atom, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. By reacting bis (trichloromethyl) carbonate with the benzyl alcohol derivative represented by the general formula (4)

(Wherein R ² , R ³ , L ¹ , L ² , L ³ , L ⁴ , L ⁵ and n represent the same meaning as in general formula (3)). The production method according to claim 1, wherein, in the general formula (1) and the general formula (2), R ² and R ³ are alkylene groups having 1 to 7 main chain carbon atoms linked to each other. The production method according to claim 2, wherein in the general formula (3) and the general formula (4), R ² and R ³ are alkylene groups having 1 to 7 main chain carbon atoms linked to each other. The production method according to claim 1, wherein bis (trichloromethyl) carbonate is allowed to act in the presence of a base such as pyridine, triethylamine or diethylamine. 6. The production method according to claim 1, wherein toluene, hexane, tetrahydrofuran, dichloromethane or 1,2-dichloroethane is used as the reaction solvent.