JPH044344B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the formula {wherein R ₁ is straight-chain or branched alkyl having 1 to 14 carbon atoms, optionally interrupted by 1 to 5 oxygen atoms, cycloalkyl;
Represents aryl optionally substituted with alkyl having 1 to 8 carbon atoms or alkoxy having 1 to 8 carbon atoms, and R ₂ is hydrogen, fluorine, chlorine, methyl, ethyl,
Represents methoxy, ethoxy, cyano, R ₃ , R ₄ ,
R ₅ is the same or different group, hydrogen, fluorine, chlorine,
Represents methyl, ethyl, methoxy, and ethoxy.
Q ₁ , Q ₂ , Q ₃ and Q ₄ are the same or different groups and represent hydrogen, fluorine, methyl or methoxy. Also with Q ₂
R ₃ , Q ₃ and R ₄ , Q ₄ and R ₅ together with the benzene ring
and -CH=CH-CH= forming a ring at the 3-position
It may also represent CH- or -CH=CH-CH=N-. n is 0 or 1. X represents straight-chain or branched alkoxy having 1-14 carbon atoms, which may be interrupted by 1-5 oxygen atoms, cycloalkyloxy or the following formula (2). (In the formula, R ₆ and R ₇ are the same or different groups, each having a straight chain or branched chain of 1 to 8 carbon atoms, which may be interrupted by hydrogen, 1 to 2 oxygen atoms) This invention relates to a cinnamate ester derivative azo dye for liquid crystals, which is represented by alkyl, cyanoethyl, or hydroxyethyl.Alternatively, R ₆ and R ₇ may form a ring together with a nitrogen atom. The azo dye of the present invention can be produced as follows. formula (In the formula, R ₁ , R ₂ , and Q ₁ have the same meanings as in formula (1).) The aminocinnamic acid derivative represented by the formula is diazotized by a conventional method to form the formula (In the formula, R ₃ and Q ₂ have the same meanings as in formula (1).) (In the formula, R ₃ and Q ₂ have the same meanings as in formula (1). (In the formula, R ₁ , R ₂ , R ₃ , Q ₁ , and Q ₂ have the same meanings as in formula (1).) A monoazo dye represented by the formula is obtained. Next, the compound of formula (6) is diazotized, and the compound of formula (6) is (In the formula, Y represents hydroxy or formula (2).) When Y is hydroxy, it is then alkylated by reacting with an alkylating agent to form a compound of formula (1). Formula corresponding to n=0 _A diazo dye _{represented by the following} formula _is obtained _: Alternatively, the compound of formula (6) can be diazotized to form the formula (In the formula, R ₄ and Q ₃ have the same meanings as in formula (1).) (In the formula, R ₄ and Q ₃ have the same meanings as in formula (1).) (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , Q ₁ , Q ₂ , Q ₃ are the formula (1)
It has the same meaning as in. ) to obtain a disazo dye represented by Next, the compound of formula (11) is diazotized and coupled to the compound of formula (7), and when Y is hydroxy, it is subsequently alkylated by reacting with an alkylating agent to form a compound of formula (7).
Formula corresponding to n=1 in (1) (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , Q ₁ , Q ₂ , Q ₃ ,
Q ₄ and X have the same meaning as in formula (1). ) is obtained. Although there are various known methods for producing the aminocinnamic acid derivative represented by formula (3), the following method is particularly advantageous. formula (In the formula, R ₂ and Q ₁ have the same meanings as in formula (1).) A compound represented by _the formula CH ₂ =CH−COOR ₁ (14) ) is condensed in the presence of a palladium catalyst and a base to give the formula (In the formula, R ₁ , R ₂ , and Q ₁ have the same meanings as in formula (1).) A compound represented by the following is obtained, and then the acetylamino group is hydrolyzed to obtain a compound of formula (3). In the above reaction, methyl acrylate, which is the most common acrylic ester of formula (14), is reacted to obtain a compound of formula (15) where R ₁ = CH ₃ , and then a higher alkyl ester compound is obtained by transesterification. This method is also effective. The crude pigment thus obtained is of sufficient quality for ordinary dyeing, coloring, etc., but if higher quality is required, recrystallization, column chromatography, etc.
A dye of desired quality can be obtained by purification by preparative high performance liquid chromatography or the like. The cinnamate ester derivative azo dye represented by formula (1) obtained by the present invention is useful as a liquid crystal coloring agent for guest-host color display, and is biphenyl-based, phenylcyclohexane-based, ester-based, and pyrimidine-based It has excellent solubility in any type of liquid crystal such as , Schiff type, azo type, and azoxy type, and also has excellent dichroism and durability required as a color liquid crystal dye. In addition, it is useful as a synthetic resin colorant, a petroleum or refrigerant colorant, and a synthetic fiber colorant. Example 1 11 parts of 4-aminocinnamic acid butyl ester and 12 parts of concentrated hydrochloric acid are charged and dissolved in 100 parts of water, and 3.4 parts of sodium nitrite dissolved in 10 parts of water is added dropwise at 5 DEG C. or lower to diazotize. Next, 12.5 parts of sodium N-methylaniline-ω-sulfonate is dissolved in 110 parts of water and added to the diazo solution at 5°C or lower. Stir at below 5℃,
Add 8.2 parts of sodium acetate to complete the reaction. After the reaction, filter and wash with water. The obtained crystals are suspended in 300 parts of water, heated to 80°C, and 40 parts of 10% caustic soda solution are added dropwise. The reaction was further carried out at 80℃ for 1 hour, then filtered, washed with water, and dried. 14.5 parts of a monoazo dye represented by was obtained. Next, 8 parts of this monoazo dye was dissolved in 100 parts of dimethylformamide, 5.5 parts of concentrated hydrochloric acid was added, and the mixture was heated at 5°C.
Below, a solution of 1.7 parts of sodium nitrite dissolved in 5 parts of water is added dropwise to diazotize. Further, 4.2 parts of N,N-diethylaniline was dissolved in 25 parts of acetic acid, and the solution was added dropwise to the diazo solution at a temperature below 10°C. Stir at below 10°C and add 4.5 parts of sodium acetate to complete the reaction. After the reaction was completed, 50 parts of water was added, filtered, washed with methanol, washed with water, and dried to obtain 9.6 parts of a crude dye. The crude dye was dissolved in xylene, and after separating the insoluble matter, it was subjected to silica gel column chromatography, developed with xylene and then a mixed solvent of xylene and ethyl acetate, and purified and fractionated. After concentrating the solvent, the precipitated crystals were overdried. A dark red dye 1 was obtained. Melting point: 168-169℃ The color of this dye dissolved in acetone is red. λmax 498nm This dye is combined with the following four types of liquid crystal compounds. BDH Chemicals Ltd.'s Liquid Crystal E, which is a mixture of
When two transparent glass electrode substrates containing 2% of -7 and subjected to homogeneous alignment treatment are placed in a cell facing each other with an interval of about 10 μm, and the voltage is turned on and off, the dichroism ratio is 12.5. It was hot. Example 2 In Example 1, N,N-diethyl-m-toluidine was used instead of N,N-diethylaniline 4.6
1 part was reacted in the same manner to obtain 10.1 parts of a crude dye. The red pigment 2 was purified in the same manner using column chromatography. Melting point: 136.5-138.5℃ The color of this dye dissolved in acetone is red. λmax 517nm 2% of this dye was added to molten crystal E-7, and Example 1
When it was sealed in a similar cell and the voltage was turned on and off, its dichroic ratio was 12. Example 3 11 parts of 4-aminocinnamic acid butyl ester was diazotized in the same manner as in Example 1, and 50 parts of water and m-toluidine were added.
Add to 6.4 parts of coupling liquid. Stir at 5℃ or below, filter after completion of reaction, wash with water, wash with methanol, and dry. 12.5 parts of a monoazo dye represented by was obtained. Next, 10.1 parts of this monoazo dye is dissolved in 100 parts of acetic acid, 6.6 parts of concentrated hydrochloric acid is added, and a solution prepared by dissolving 2.1 parts of sodium nitrite in 6.5 parts of water is added dropwise at 5° C. or lower to diazotize the mixture. Further, 3.7 parts of m-toluidine is dissolved in 20 parts of acetic acid, and the solution is added dropwise to the diazo solution at a temperature below 10°C.
Stir at 10℃ or less, and after the reaction is complete, add 50 parts of water, filter, wash with water, wash with methanol, and dry. 11.6 parts of crude product were obtained. Furthermore, 11.6 parts of this disazo dye was dissolved in 100 parts of dimethylformamide, and 5.6 parts of concentrated hydrochloric acid was added.
Diazotize by adding dropwise a solution of 1.8 parts of sodium nitrite dissolved in 5.5 parts of water below ℃. Furthermore, 4.4 parts of N,N-diethylaniline was added to 25 parts of acetic acid.
and dropwise dropwise into the diazo solution at a temperature below 10°C. Stir at below 10°C and add 4.6 parts of sodium acetate to complete the reaction. After the reaction is complete, add 50 parts of water, filter, wash with water, wash with methanol, and dry to obtain a crude dye of 13.6
I got the department. The product was similarly purified by column chromatography to obtain dark red pigment 3. Melting point: 171-173℃ The color of this dye dissolved in acetone is red. λmax 505nm 2% of this dye was added to liquid crystal E-7 and Example 1
The dichroic ratio was 13 when the cell was sealed in a cell similar to the one shown in Figure 1 and the voltage was turned on and off. Example 4 13.8 parts of 4-aminocinnamic acid-2'-ethylhexyl ester and 12 parts of concentrated hydrochloric acid were added to 100 parts of water.
At 5°C or lower, 3.4 parts of sodium nitrite is dissolved in 10 parts of water and added dropwise to diazotize. Next, 12.5 parts of sodium N-methylaniline-ω-sulfonate is dissolved in 110 parts of water and added to the diazo solution at 5°C or lower. Stir at below 5°C and add 8.2 parts of sodium acetate to complete the reaction. After the reaction, filter and wash with water. The obtained crystals are suspended in 300 parts of water, heated to 80°C, and 40 parts of 10% caustic soda solution are added dropwise. 1 more
React at 80℃ for an hour, cool, filter, wash with water, dry and form 16.5 parts of a monoazo dye represented by was obtained. next,
Dissolve 11.4 parts of this monoazo dye in 150 parts of acetic acid, add 6.6 parts of concentrated hydrochloric acid, and add 2.1 parts of sodium nitrite at below 5°C.
1 part dissolved in 6.5 parts of water is added dropwise to diazotize.
Furthermore, N,N-dimethyl-α-naphthylamine 5.9
1 part is dissolved in 30 parts of acetic acid and added dropwise to the diazo solution at 10°C or below. Stir at below 10°C and add 5.4 parts of sodium acetate to complete the reaction. After the reaction was completed, the mixture was filtered, washed with water, washed with methanol, and dried to obtain 13.2 parts of a crude dye. The product was similarly purified by column chromatography to obtain dark red dye 5. Melting point: 98-99℃ The color of this dye dissolved in acetone is reddish-purple. λmax 545nm 2% of this dye was added to liquid crystal E-7 and Example 1
The dichroic ratio was 11 when the cell was sealed in a cell similar to the one shown in Figure 1 and the voltage was turned on and off. Example 5 Eight parts of the monoazo dye represented by formula (16) are diazotized according to Example 1. Next, 3.2 parts of caustic soda and 2.7 parts of phenol are dissolved in 30 parts of water, and the solution is added dropwise to the diazo solution at 10°C or lower. Stir at below 10°C to complete the reaction. After the reaction is complete, add 80 parts of water, neutralize with hydrochloric acid, filter, wash with water, and dry. 9.4 parts of a disazo dye represented by was obtained. next,
Dissolve this dye in 100 parts of methyl cellosolve,
4.5 parts of anhydrous potassium carbonate and 8.9 parts of toluenesulfonic acid heptyl ester were added, and the mixture was heated at 90-100°C.
Allow time to react. After cooling, add 200 parts of water, filter, wash with water, wash with methanol, and dry to obtain a crude pigment of 9.5
I got the department. The product was similarly purified by column chromatography to obtain orange dye 6. Melting point: 137-138℃ The color of this dye dissolved in acetone is yellow. λmax 391nm 1% of this dye was added to liquid crystal E-7, and Example 1
The dichroic ratio was 13.5 when the cell was sealed in a cell similar to the one shown in Figure 1 and the voltage was turned on and off. Example 6 In Example 5, 4.2 parts of α-naphthol was used instead of phenol and the reaction was carried out in the same manner to obtain the formula 10.3 parts of a disazo dye represented by was obtained. Furthermore, it was heptylated in the same manner as in Example 5 to obtain 10.9 parts of a crude dye. The product was purified in the same manner using column chromatography to obtain orange-red dye 7. Melting point: 137.5-139℃ The color of this dye dissolved in acetone is orange. λmax 435nm 1% of this dye was added to liquid crystal E-7, and Example 1
When it was sealed in a similar cell and the voltage was turned on and off, its dichroic ratio was 12. Other dyes represented by formula (1) of the present invention can be synthesized according to Examples 1 to 6. Table 1
The structures and acetone-soluble colors of typical pigments are described. These dyes were sealed in the same cell as in Example 1, and exhibited excellent dichroism when the voltage was turned on and off.

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Claims (1)

[Claims] 1 formula {wherein R ₁ is straight-chain or branched alkyl having 1 to 14 carbon atoms, optionally interrupted by 1 to 5 oxygen atoms, cycloalkyl;
Represents aryl optionally substituted with alkyl having 1 to 8 carbon atoms or alkoxy having 1 to 8 carbon atoms, and R ₂ is hydrogen, fluorine, chlorine, methyl, ethyl,
Represents methoxy, ethoxy or cyano, R ₃ ,
R ₄ and R ₅ are the same or different groups, hydrogen, fluorine,
Represents chlorine, methyl, ethyl, methoxy or ethoxy. Q ₁ , Q ₂ , Q ₃ and Q ₄ are the same or different groups and represent hydrogen, fluorine, methyl or methoxy. Also, Q ₂ and R ₃ , Q ₃ and R ₄ , Q ₄ and R ₅ form a ring together with the benzene ring at the 2 and 3 positions -CH=
It may also represent CH-CH=CH- or -CH=CH-CH=N-. n is 0 or 1. X represents straight-chain or branched alkoxy having 1-14 carbon atoms, which may be interrupted by 1-5 oxygen atoms, cycloalkyloxy or the following formula (2). (In the formula, R ₆ and R ₇ are the same or different groups, each containing hydrogen, a straight chain or branched chain of 1 to 6 carbon atoms optionally interrupted by 1 to 2 oxygen atoms) or R ₆ and R ₇ may form a ring together with a nitrogen atom.