JPH08291085A - Production of tolan compound - Google Patents

Abstract

PURPOSE: To industrially and advantageously obtain a tolan compound excellent in refractive index anisotropy and useful for liquid crystal elements by reacting a specific acetylene compound with an alkenyl compound in the presence of a metal catalyst and a basic substance. CONSTITUTION: (C) A compound of formula I X<1> to<4> are each CH, CF or N; A is H, F, CF3 , OCF3 , CN, a group of the formula R<1> -(cycloalkyl) (R<1> is a 1-12C alkyl, a 3-12C alkenyl or a 3-12C alkynyl), a group of the formula R<1> -(cycloalkenyl) or a group of the formula R<1> -(O)m [(m) is 0 or 1]} is reacted with (D) a compound of formula II Y<1> to Y<4> are each X<1> ; R is R<1> or a 2-12C alkoxyalkyl; D is a halogen or a group of the formula SO2 R' [R' is an (F- substituted)lower alkyl or a (substituted)phenyl]} in the presence of a metal catalyst such as a palladium-based, nickel-based or rhodium-based metal catalyst to provide the objective compound of formula III.

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 tolan compound which is useful as a compounding ingredient of liquid crystal compositions.

[0002]

2. Description of the Related Art In recent years, high performance of liquid crystal display devices has become indispensable with the advent of the information society. Among various physical properties of the liquid crystal composition, a material having excellent refractive index anisotropy is required for higher speed and higher performance. However, at present, a liquid crystal material having a sufficient refractive index anisotropy has not been found.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an industrially advantageous method for producing a liquid crystal compound having excellent refractive index anisotropy.

[0004]

In view of the above, the present inventors have conducted diligent studies on a method for producing a liquid crystal compound having excellent refractive index anisotropy, and as a result, have found an advantageous method for producing such a compound. Heading out, the present invention was reached.

That is, the present invention has the general formula [2]

[Chemical 6] (In the formula, X ¹ , X ² , X ³ and X ⁴ are the same or different and represent CH, CF or N, and A is a hydrogen atom, a fluorine atom, a trifluoromethyl group, a trifluoromethoxy group,
Cyano group, R ^1- (cycloalkyl) group, R ^1- (cycloalkenyl) group or R ^1- (O) m group, wherein R ¹ is a C ₁ -C ₁₂ alkyl group, C _3- A C ₁₂ alkenyl group or a C ₃ -C ₁₂ alkynyl group is shown, and m is 0 or 1. ) And an acetylene compound represented by the general formula [3]

[Chemical 7](In the formula, Y¹, Y², Y³And Y^FourAre the same or different
Represents CH, CF or N, and R is C₁ ~ C₁₂A
Rukiru group, C₃~ C₁₂Alkenyl group of C₃~ C ₁₂A
Lucinyl group or C₂~ C₁₂The alkoxyalkyl group of
, D is a halogen atom or -SO₂R'is shown. Was
However, R'is a lower atom which may be substituted with a fluorine atom.
Is a phenyl group or an optionally substituted phenyl group.
You ) An alkenyl compound represented by
Reacting in the presence of a basic substance, the compound of the general formula [1]

Embedded image (In the formula, A, R, X ¹ , X ² , X ³ , X ⁴ , Y ¹ ,
Y ² , Y ³ and Y ⁴ each have the same meaning as described above. ) And a general formula [4]

[Chemical 9] (In the formula, A, D, X ¹ , X ² , X ³ and X ⁴ have the same meanings as described above.) And the general formula [5].

[Chemical 10] (Wherein R, Y ¹ , Y ² , Y ³ and Y ⁴ each have the same meaning as described above), and the reaction is carried out in the presence of a metal catalyst and a basic substance. The present invention provides a method for producing the tolan compound represented by the above general formula [1].

The present invention will be described in detail below. The tolan compound [1] obtained in the present invention is obtained by reacting an acetylene compound represented by the general formula [2] with an alkenyl compound represented by the general formula [3] in the presence of a metal catalyst and a basic substance. Alternatively, it can be obtained by reacting an aromatic compound represented by the general formula [4] with an acetylene derivative represented by the general formula [5] in the presence of a metal catalyst and a basic substance.

The raw material acetylene compound [2] is
It can be synthesized by the following method.

[Chemical 11]

The other alkenyl compound [3] and acetylene derivative [5] can be synthesized, for example, by the method shown below.

[Chemical 12]

In the reaction for obtaining the tolan compound [1] from the acetylene compound [2] and the alkenyl compound [3], the amount of the acetylene compound [2] used is usually 0.9 to the alkenyl compound [3]. It is 3 times equivalent, but preferably 1 to 2 times equivalent. Of course, the compound [3] can be used in excess, but since the compound [3] is generally more expensive, it is preferable to use the compound [2] in an excess amount.

In the reaction for obtaining the tolan compound [1] from the aromatic compound [4] and the acetylene derivative [5],
The amount of the aromatic compound [4] used is usually 0.9 to 3 times the equivalent amount of the acetylene derivative [5], but preferably 1 to 2 times the equivalent amount. Of course, the acetylene derivative [5] can be used in excess, but since the acetylene derivative [5] is generally more expensive, it is preferable to use the aromatic compound [4] in an excess amount.

As the metal catalyst, in the palladium system, palladium chloride, palladium acetate, triphenylphosphine palladium complex, palladium / carbon, etc. are used.
The catalysts similar to those of the above palladium type are used for nickel type and rhodium type. The amount of these metal catalysts used is usually in the range of 0.001 to 0.1 times the equivalent of the raw material aromatic halide [3] or acetylene derivative [5].

In this reaction, in addition to the above metal catalyst, a trivalent phosphorus compound or a trivalent arsenic compound may be used as a cocatalyst.

[Chemical 13]

(In the formula, Y represents a phosphorus atom or an arsenic atom, and R ² , R ³ and R ⁴ are the same or different and each represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a halogen atom.) And specifically includes tri-n-butylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-n-butylphosphine,
Examples include o-tolyl phosphite, phosphorus trichloride, triphenylarsenic and the like. The amount of the phosphorus compound or arsenic compound used is 0.5 to 50 times equivalent, preferably 1 to 30 times equivalent to the above metal catalyst.

In addition to these catalysts, a copper catalyst may be used. Examples of such a copper catalyst include copper iodide, copper bromide,
Copper chloride, copper oxide, copper cyanide and the like can be mentioned, and the amount of these used is usually in the range of 0.001 to 0.1 times the equivalent of the starting alkenyl compound [3] or acetylene derivative [5]. Of course, it is possible to use more than this.

Examples of the basic substance include alkali metal carbonates, carboxylates, alkoxides, hydroxides and the like, and organic bases, more specifically, hydroxides such as sodium hydroxide and potassium hydroxide. , Carbonates such as sodium carbonate, sodium hydrogen carbonate, potassium carbonate and potassium hydrogen carbonate, alkoxides such as sodium methylate and sodium ethylate, diethylamine, triethylamine, di-isopropylethylamine, tri-n-butylamine, tetramethylethylenediamine, dimethyl. Organic bases such as aniline, N-methylmorpholine, N-methylpiperidine, piperidine and pyrrolidine are preferably used. The amount of the basic substance used is usually 1 with respect to the alkenyl compound [3] or the acetylene derivative [5].
~ 5 times equivalent.

In the above reaction, if necessary, a suitable solvent such as toluene, pyridine, picoline, acetonitrile, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, hexamethylphosphorylamide, N
-Methylpyrrolidone, methanol, ethanol, 2-propanol, methyl ethyl ketone and the like can be used as a reaction solvent. Further, the above base can be used as a solvent. The amount of these reaction solvents used is not particularly limited. Further, when the basic substance is insoluble in the organic solvent, it is possible to add water to carry out the reaction in a homogeneous system or a heterogeneous system.

In the reaction, the yield of the target compound can be improved by increasing the reaction temperature, but since the by-product increases at too high temperature, the reaction temperature is usually 15 to 160 ° C. Preferably 30-140
° C. After completion of the reaction, the tolan compound [1] can be obtained by an ordinary means such as extraction, distillation, recrystallization and the like.
If necessary, it can be purified by column chromatography or recrystallization.

Specific examples of the tolan compound [1] obtained in the present invention are, for example, in the general formula [1], A is methyl, ethyl, propyl, butyl,
Pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, propenyl, butenyl,
Pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl, decynyl, undecynyl,
Dodecynyl, methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, vinyloxy, propenyloxy, butenyloxy, pentenyloxy, hexenyloxy, heptenyloxy, octenyl. Oxy, nonenyloxy, decenyloxy, propynyloxy, butynyloxy, pentynyloxy, hexynyloxy, heptynyloxy, octynyloxy, nonylyloxy, dodecynyloxy, 4-propylcyclohexyl, 4-propylcyclohexenyl, 4-pentylcyclohexyl, 4-pentylcyclohexenyl, fluorine atom, Examples thereof include trifluoromethyl group, trifluoromethoxy group and cyano group.

R is methyl, ethyl, propyl,
Butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, propynyl, butynyl, pentynyl, hexenyl,
Heptinyl, octynyl, nonynyl, decynyl, undecynyl, dodecynyl, methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl, pentyloxymethyl, hexyloxymethyl, heptyloxymethyl, octyloxymethyl, nonyloxymethyl, decyloxymethyl, methoxyethyl. , Ethoxyethyl, propoxyethyl, butoxyethyl, pentyloxyethyl, hexyloxyethyl, heptyloxyethyl, octyloxyethyl, nonyloxyethyl, decyloxyethylmethoxypropyl, ethoxypropyl, propoxypropyl, butoxypropyl, pentyloxypropyl, hexyl Oxypropyl, heptyloxypropyl, octyloxypropyl, nonyloxypropyl,
Decyloxypropyl methoxybutyl, ethoxybutyl, propoxybutyl, butoxybutyl, pentyloxybutyl, hexyloxybutyl, heptyloxybutyl, octyloxybutyl, nonyloxybutyl, decyloxybutyl, methoxypentyl, ethoxypentyl, propoxypentyl, butoxypentyl. , Pentyloxypentyl, hexyloxypentyl, heptyloxypentyl, octyloxypentyl and the like.

[0020]

INDUSTRIAL APPLICABILITY According to the present invention, the tolan compound represented by the general formula [1] can be industrially advantageously produced. Since this compound has very excellent properties as a liquid crystal compound, Further, it can be effectively used as a liquid crystal element using the same.

[0021]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) 4 equipped with a thermometer and a stirrer
In a two-necked flask, 2-methyl-4- [4- (1-trans
-Pentenyl) -phenyl] -3-butyn-2-ol
3.0 g (13.1 mmol), 4-bromobenzonitrile
Charged 3.1 g (17.1 mmol), toluene 25 g, water 5 g, sodium hydroxide 1.1 g (26.3 mmol), tetrakistriphenylphosphine palladium 0.1 g, 80
The mixture was stirred at 0 ° C for 6 hours. After completion of the reaction, the liquid was separated and the oil layer was washed with 10
% Hydrochloric acid, water, aqueous sodium hydrogen carbonate, and water in that order. The oil layer was concentrated and then purified by silica gel column chromatography to obtain 4- [4- (1-trans-pentenyl) -phenylethynyl] -benzonitrile 2.6 g (yield 74%).

(Example 2) 4 equipped with a thermometer and a stirrer
In a two-necked flask, 4- (4-fluoro-phenyl) -2
-Methyl-3-butyn-2-ol 3.0 g (16.9 mmol), 1-bromo-4- (1-trans-pentenyl)-
2.7 g (12.0 mmol) of benzene, 25 g of toluene, 5 g of water, 1.0 g (25.0 mmol) of sodium hydroxide and 0.1 g of tetrakistriphenylphosphine palladium were charged, and the mixture was stirred at 80 ° C. for 6 hours. After completion of the reaction, the layers were separated, and the oil layer was washed successively with 10% hydrochloric acid, water, aqueous sodium hydrogen carbonate and water. The oil layer was concentrated and then purified by silica gel column chromatography to obtain 4- [4- (1-trans-pentenyl) -phenylethynyl] -1-fluoro-benzene (2.3 g, yield 73%).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07C 17/263 C07C 17/263 22/08 22/08 25/24 25/24 43/23 7419- 4H 43/23 C 255/49 255/49 C07D 237/08 C07D 237/08 239/26 239/26 241/12 241/12 // C07B 61/00 300 C07B 61/00 300

Claims (2)

[Claims] 1. A general formula [2]:(In the formula, X¹, X², X³And X^FourAre the same or different
Represents CH, CF or N, A is a hydrogen atom,
Elementary atom, trifluoromethyl group, trifluoromethoxy group,
Cyano group, R¹ -(Cycloalkyl) group, R¹ -(Siku
Alkenyl) group or R¹ Indicates a-(O) m group, where
And R¹ Is C₁ ~ C₁₂Alkyl group of C₃~ C₁₂Al
Kenyl group or C₃~ C₁₂Is an alkynyl group of
It is 0 or 1. ) With an acetylene compound
General formula [3](In the formula, Y¹, Y², Y³And Y^FourAre the same or different
Represents CH, CF or N, and R is C₁ ~ C₁₂A
Rukiru group, C₃~ C₁₂Alkenyl group of C₃~ C ₁₂A
Lucinyl group or C₂~ C₁₂The alkoxyalkyl group of
, D is a halogen atom or -SO₂R'is shown. Was
However, R'is a lower atom which may be substituted with a fluorine atom.
Is a phenyl group or an optionally substituted phenyl group.
You ) An alkenyl compound represented by
Generally characterized by reacting in the presence of a basic substance
Formula [1](In the formula, A, R, X¹, X², X³, X^Four, Y¹,
Y², Y³And Y^FourRespectively have the same meaning as above.
I forgot. ) The manufacturing method of the tolan compound shown by these. 2. A general formula [4]: (In the formula, A, D, X ¹ , X ² , X ³ and X ⁴ each have the same meaning as described above.) And an aromatic compound represented by the general formula [5] (Wherein R, Y ¹ , Y ² , Y ³ and Y ⁴ each have the same meaning as described above), and the reaction is carried out in the presence of a metal catalyst and a basic substance. The method for producing a tolan compound represented by the above general formula [1].