JPH07112990A - Method for producing silacyclohexane compound - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for synthesizing 4-arylsilacyclohexane by a cyclization reaction by silicon-carbon bond formation in an industrially satisfactory yield. [Structure] General formula (1) (In the formula, Z ¹ and Z ² are each independently a hydrogen atom, a halogen atom, an aryl group, an alkyl group or an alkoxy group having 2 to 10 carbon atoms, M is a magnesium atom or a zinc atom,
X and X'represent a halogen atom, and n represents an integer of 0-4. ) A 3-arylpentane-1,5-bis metal compound represented by the general formula (2) (In the formula, R represents an alkyl group having 2 to 10 carbon atoms, W represents a hydrogen atom, a halogen atom, a methyl group or a methoxy group, and Y represents a halogen atom or a methoxy group). By the carbon bond forming reaction, the general formula (3) ^{(Wherein, Z 1,} Z ^2, R and W are the general formula (1) or ^(Z 1 in ^{2), Z} 2, shows the same atom or group as R and W.) Represented by 4-aryl A method for producing a 4-arylsilacyclohexane compound, which comprises synthesizing a silacyclohexane compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a 4-arylsilacyclohexane compound used as a liquid crystal compound used as a display material for electro-optical switching or a display device or a synthetic intermediate thereof.

[0002]

2. Description of the Related Art A method for synthesizing a silacyclohexane ring by reacting a bis-Grignard reagent derived from 1,5-dihalopentane with a silane having a leaving group on silicon is described in West (J. Amer. Chem. Soc. 76
6012 (1954)). But,
In the case of silacyclohexane having a substituent at the 4-position, that is, there are few synthetic examples of 4-organosilacyclohexane from a 3-organopentane-1,5-bis-metal compound. Sakurai et al. Synthesized 4-tert-butylsilacyclohexane compounds and led them to various derivatives for stereochemical studies in silacyclohexane system (Bull. Ch.
em. Soc. Jpn. 49 3185 (197)
6)). In these synthetic examples, it was reported that the yield of the cyclized target compound was remarkably reduced when the number of the chloro group as the leaving group was decreased due to the presence of the alkyl group on the silicon subjected to the nucleophilic substitution. There is.

[0003]

From the above synthesis example, 3-
The synthesis of 4-arylsilacyclohexane compounds by the coupling reaction of arylpentane-1,5-bis-metal reagents with alkyl-substituted silanes, especially long-chain alkyl-substituted silanes, has been considered difficult.

An object of the present invention is to solve this problem and to provide a method for synthesizing 4-arylsilacyclohexane by a cyclization reaction by forming a silicon-carbon bond at an industrially satisfactory yield.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned object, the present inventors have found the following method.

That is, the present invention is based on the general formula (1)

[Chemical 4] (In the formula, Z ¹ and Z ² are each independently a hydrogen atom, a halogen atom, an aryl group, an alkyl group or an alkoxy group having 2 to 10 carbon atoms, M is a magnesium atom or a zinc atom, X
And X'represent a halogen atom, and n represents an integer of 0-4. )
And a 3-arylpentane-1,5-bis metal compound represented by the general formula (2)

[Chemical 5] (In the formula, R represents an alkyl group having 2 to 10 carbon atoms, W represents a hydrogen atom, a halogen atom, a methyl group or a methoxy group, and Y represents a halogen atom or a methoxy group.) Silicon with a silane compound By the carbon bond forming reaction, the general formula (3)

[Chemical 6] (Wherein Z ¹ , Z ² , R and W represent the same atom or group as Z ¹ , Z ² , R and W in the general formula (1) or (2)). A method for producing a 4-arylsilacyclohexane compound, which comprises synthesizing a silacyclohexane compound.

Y in the silane compound represented by the general formula (2) is, for example, a fluorine atom or a methoxy group.

The present invention will be described in more detail below.

The 3-arylpentane-1,5-bis-metal compound has the formula

[Chemical 7](In the formula, Z¹, Z², M, X and X ′ Is the general formula (1)
At Z¹, Z², M, X and X The same atom or group as
Shows, X¹And X²Represents a halogen atom. )
Synthesized from 3-aryl-1,5-dihalopentane
To be done.

When M is a magnesium atom, it can be converted to a bis-Grignard reagent by reacting with metallic magnesium in a conventional manner. In this case, by selecting an appropriate halogen (for example, a bromine atom or an iodine atom) for X ¹ and X ² and selecting reaction conditions, the substituents Z ¹ and Z ² on the aromatic ring can be selected.
Is a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom), magnesium is introduced into the primary alkyl halide moiety, that is, the X ¹ moiety without causing a reaction in the Z ¹ and Z ² moieties. It can be a Grignard reagent.

When M is a zinc atom, a bis-zinc reagent can be prepared by reacting a bis-Grignard reagent with a halogen zinc, such as zinc chloride or zinc bromide, and performing a metal exchange reaction. Further, a metal exchange reaction between zinc halide and a bis-lithium reagent is also possible.

As a solvent for these metal reagent preparation reactions,
Examples thereof include ethers such as diethyl ether, di-n-butyl ether, tetrahydrofuran and dimethoxytane, and hydrocarbons such as n-hexane, n-heptane, benzene, toluene, xylene and cumene are mixed and used. Good. In order to start or accelerate the reaction, it is also effective to react under heating or to apply ultrasonic waves.

Next, the following equation

[Chemical 8] (In the formula, Z ¹ , Z ² , M, X, X ′, W, Y and R are Z ¹ , Z ² , M, X in the general formula (1) or (2).
The same atom or group as X ', W, Y and R is shown. ), The synthesized bis-metal reagent and the silane compound are reacted to synthesize a silacyclohexane compound.

The leaving group Y on silicon of the silane compound is a halogen atom or an alkoxy group, and a fluorine atom, a chlorine atom and a methoxy group can be preferably exemplified. In particular, when the alkyl substituent has a relatively long chain, that is, when it has 5 to 10 carbon atoms, a fluorine atom or a methoxy group gives a cyclized product in a high yield.

When W, which is a substituent of silicon of the desired silacyclohexane compound, is a halogen atom or an alkoxy group, the use of a silane compound in which Y is the same as W increases the probability of the cyclization reaction and increases the yield. Bring about an improvement.

As the reaction solvent, diethyl ether, di-n-butyl ether, tetrahydrofuran, 1,4-
Ethers such as dioxane and dimethoxyethane are preferable, and n-hexane, n-heptane, benzene,
Hydrocarbons such as toluene, xylene, cumene, or N, N-dimethylformamide, 1,3-dimethyl-2
-Aprotic polar solvents such as imidazolidinone, hexamethylphosphoric triamide, N, N-tetramethylethylenediamine and the like can also be mixed and used.

The reaction temperature may be in the range of 0 to 120 ° C., but the range of 30 to 100 ° C. is preferable from the viewpoint of reaction rate and yield.

The produced 4-arylsilacyclohexane compound can be isolated from the reaction mixture by a conventional process of extraction, washing and concentration. However, when the product has a halogen atom or an alkoxy group as a substituent on silicon, the reaction solvent may be removed under reduced pressure, and the resulting metal salt may be removed by filtration. When a substance of higher purity is desired, it can be purified by a method such as ordinary chromatography, vacuum distillation or recrystallization.

[0019]

EXAMPLES Examples of the present invention will be shown below. The present invention is not limited to the description of this embodiment.

[Example 1] (Synthesis of 4-p-chlorophenyl-1-fluoro-1-n-octyl-1-silacyclohexane) 1-bromo-
5-chloro-3- (p-chlorophenyl) pentane (1
The bis Grignard reagent was prepared from 400 millimoles (80 millimoles) and magnesium metal (200 milligram atoms) in 400 ml ether. This is trifluoro-n-octylsilane (150 mmol) and 400 ml of tetrahydrofuran.
The mixture was added dropwise to the mixture of and stirred at 50 ° C. for 4 hours. After the reaction solvent was removed under reduced pressure, n-pentane was added and the resulting precipitate was filtered off. The residue obtained by concentrating the filtrate was distilled under reduced pressure to obtain 35.3 g of the desired product (yield 69%).

The results of identification by GC-MS and IR are shown below. GC-MS (EI) m / e ⁺ : 284, 312, 340
(M ⁺ ) IR (liquid film) νmax: 2920, 2855, 149
0,1095,820 cm ^-1

Example 2 (Synthesis of 1-n-heptyl-1 methyl-4-phenyl-1-silacyclohexane) Bis-Grignard reagent prepared from 1,5-dibromo-3-phenylpentane and n-
Reaction was carried out in the same manner as in Example 1 from heptylmethyldifluorosilane. The reaction mixture was poured into diluted hydrochloric acid and extracted with methylene chloride. The extract was treated with NaHCO ₃ aq and NaCl aq.
The extract was washed with water, dried over MgSO ₄ , and then concentrated under reduced pressure. The residue was purified by column chromatography to obtain the desired product with a yield of 33%.

The results of identification by GC-MS and IR are shown below. GC-MS (EI) m / e +: 189 ((M-C 7 H 15)
^{+), 260 ((M-} C 2 H 4) +) IR ( liquid film) νmax: 2910,2845,149
5,1455,1250,875cm ^-1

[Examples 3 to 14] Z ¹ , Z ² , M, X,
Atoms or groups as shown in Table 1 were selected as R, W and Y to synthesize the silacyclohexane compounds of Examples 3 to 14, and the yields shown in Table 1 were obtained.

[0025]

[Table 1]

[0026]

As described above, according to the present invention, it is possible to provide a method for synthesizing 4-arylsilacyclohexane by a cyclization reaction by forming a silicon-carbon bond at an industrially satisfactory yield. .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takaaki Shimizu 28, Nishi-Fukushima, Chugaku-mura, Nakakubiki-gun, Niigata Prefecture 1 Shin-Etsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. A compound represented by the general formula (1): (In the formula, Z ¹ and Z ² are each independently a hydrogen atom, a halogen atom, an aryl group, an alkyl group or an alkoxy group having 2 to 10 carbon atoms, M is a magnesium atom or a zinc atom, X
And X'represent a halogen atom, and n represents an integer of 0-4. )
And a 3-arylpentane-1,5-bis metal compound represented by the following general formula (2): (In the formula, R represents an alkyl group having 2 to 10 carbon atoms, W represents a hydrogen atom, a halogen atom, a methyl group or a methoxy group, and Y represents a halogen atom or a methoxy group.) Silicon with a silane compound By the carbon bond forming reaction, the compound represented by the general formula (3): (Wherein Z ¹ , Z ² , R and W represent the same atom or group as Z ¹ , Z ² , R and W in the general formula (1) or (2)). A method for producing a 4-arylsilacyclohexane compound, which comprises synthesizing a silacyclohexane compound. 2. The Y in the silane compound represented by the general formula (2) is a fluorine atom or a methoxy group.
A method for producing the 4-arylsilacyclohexane compound described.