JPH08310996A - Production of benzoic acid group-bearing (meth)acrylic ester - Google Patents

Abstract

PURPOSE: To obtain the subject ester useful as a raw material for functional high polymers such as polymeric liquid crystals, by using, as solvent, acrylic acid or methacrylic acid alone, without the need of using any highly toxic solvent and highly lacrimatory and hard-to-handle acrylic chloride. CONSTITUTION: In obtaining the objective ester from (B) acrylic acid or methacrylic acid and (C) a hydroxyalkyl-bearing benzoic acid derivative [e.g. a compound of the formula (R is an alkylene; X is O or S), e.g. 3- methoxybutylene] in the presence of (A) an acid catalyst (e.g. sulfuric acid), the component B alone is used as solvent. It is preferable that the molar ratio B/C be (1.0-100), the amount of the component A account for 0.5-50mol% of the component C, and the reaction be carried out at 50-80 deg.C.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a process for producing a (meth) acrylic acid ester containing an aromatic ring, which is a raw material for functional polymers such as polymer liquid crystals.

[0002]

2. Description of the Related Art No benzoic acid moiety is contained in a molecule (meta)
A method for producing an acrylic ester (acrylic ester or methacrylic ester) has been known for a long time. For example, Japanese Patent Publication No. 60-42777 uses (meth) acrylic acid and alcohol in the presence of an acid catalyst. There is a description regarding a method for producing a (meth) acrylic acid ester. This method has also been applied to a method for producing a (meth) acrylic acid ester from a benzoic acid derivative having a hydroxylalkyl group. For example, a research report by M. Portugall et al. [Makromol. Chem. 183, 2311 ( 1982)]]. It can be produced by a method using excess (meth) acrylic acid in the presence of chloroform, which is an azeotropic solvent with water. However, chloroform used in this method is known to be highly toxic. Further, benzene, which is generally used as an azeotropic solvent with water at 100 ° C. or lower, is also highly toxic. Therefore, a manufacturing technique that does not use these highly toxic solvents has been desired.

As another method, for example, DJ Broer
Et al. [Makromol. Chem. 190, 2255 (1989)]
] The method of using the (meth) acrylic acid chloride described in] is known. However, this method also has a problem that (meth) acrylic acid chloride has a strong tearing property and is difficult to handle, and further, a by-product is generated in the reaction.

[0004]

Therefore, an object of the present invention is to produce chloroform, which is an azeotropic solvent with highly toxic water when producing a (meth) acrylic acid ester of a benzoic acid derivative having a hydroxyalkyl group. It is an object of the present invention to provide a production method that does not use benzene or benzene, has strong tearing property, is difficult to handle, and produces a by-product in the reaction, and does not use an allyl chloride.

[0005]

As a result of intensive studies, the present inventors have found that the object of the present invention can be achieved by the following production method. (1) In the method for producing an acrylic acid ester of a hydroxy group or a methacrylic acid ester from acrylic acid or methacrylic acid and a benzoic acid derivative having a hydroxyalkyl group in the presence of an acid catalyst, acrylic is used as a solvent for the benzoic acid derivative. A method for producing an ester, which comprises using only an acid or methacrylic acid. (2) The method for producing an ester according to item (1), wherein the benzoic acid derivative having a hydroxyalkyl group is a compound represented by the following general formula (1). General formula (1)

[0006]

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R represents an alkylene group. X represents an oxygen atom or a sulfur atom. (3) The amount of acrylic acid or methacrylic acid used is 1.0 times or more the molar ratio of 100 or more with respect to the benzoic acid derivative.
Method within the range of (1)

The preferred embodiments of the present invention are as follows. (4) The method according to item (3), wherein the amount of acrylic acid or methacrylic acid used is 5 times or more and 100 times or less in molar ratio with respect to the benzoic acid derivative. (5) The method according to item (4), wherein the amount of acrylic acid or methacrylic acid used is 10 times or more and 100 times or less in molar ratio with respect to the benzoic acid derivative. (6) The amount of the acid catalyst used is based on the benzoic acid derivative.
The method according to item (1), which is 0.1 to 200 mol%. (7) The amount of the acid catalyst used is based on the benzoic acid derivative.
The method according to item (6), which is 0.5 to 50 mol%. (8) The method according to item (1), wherein the production is carried out at 30 to 100 ° C. (9) The method according to item (8), wherein the production is carried out at 50 to 80 ° C. (10) R is an alkylene group having 2 to 30 carbon atoms (2)
The method described in the section.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The amount of (meth) acrylic acid used is preferably more than 1.0 times and 100 times or less, more preferably 5 times or more in terms of molar ratio with respect to the charged molar amount of the benzoic acid derivative having a hydroxyalkyl group. . More preferably, the molar ratio is 10 times or more. When the amount of (meth) acrylic acid used is less than 5 times the molar ratio, the production rate of by-products slightly increases, and when it is not excessive, the production rate of by-products significantly increases.

As the acid catalyst, for example, an inorganic acid (for example,
Hydrogen chloride, sulfuric acid, organic acid (eg sulfonic acid (eg substituted or unsubstituted alkyl sulfonic acid (eg
Methanesulfonic acid, trifluoromethanesulfonic acid),
Substituted or unsubstituted benzenesulfonic acid (eg, paratoluenesulfonic acid, benzenesulfonic acid), carboxylic acid (eg, aromatic carboxylic acid (eg, perfluorobenzoic acid)), aliphatic carboxylic acid (eg, trifluoroacetic acid) , Trichloroacetic acid)) and solid acids (eg amberlyst, activated clay), of which sulfuric acid and sulfonic acid are particularly preferred. The addition amount of the acid catalyst is preferably 0.1 to 200 mol% or more, and more preferably 0.5 to 50 mol% or more with respect to the charged molar amount of the benzoic acid compound having a hydroxyalkyl group.
Only the reaction rate is affected by the addition amount of the acid catalyst. Therefore, when the addition amount is 0.1 mol% or less, it takes a long time to complete the reaction.

The present invention provides a solvent for a benzoic acid derivative,
General solvents (for example, alcohol solvents (for example, methanol, ethanol, isopropanol), aromatic solvents (for example, benzene, toluene, pyridine), ether solvents (for example, diethyl ether, tetrahydrofuran), ester solvents (for example) , Ethyl acetate), halogenated solvents (eg dichloromethane, chloroform), ketone solvents (eg acetone), chain hydrocarbon solvents (eg hexane, pentane), aprotic polar solvents (eg dimethylformamide, It is characterized by not using dimethyl sulfoxide)) or the like.

The reaction temperature is 30 to 100 ° C, preferably 50 to 80 ° C. Although it is not always necessary to remove the water generated by the reaction to the outside of the system, it is preferable to remove the water when the remaining raw materials pose a problem. In that case, a method can be used in which water is removed from the system together with (meth) acrylic acid after the reaction reaches equilibrium. When water is removed from the system, it is preferably performed under reduced pressure in order to keep the temperature at 50 to 80 ° C. The polymerization inhibitor is usually used as a (meth) acrylic acid polymerization inhibitor, for example, phenothiazine, hydroquinone, hydroquinone monomethyl ether, nitrobenzene, t-butylcatechol, and inorganic salts such as copper chloride and copper sulfide. Can be applied as is. The amount of the polymerization inhibitor added is 10 to the weight of the (meth) acrylic acid used.
10,000 ppm is preferable, and more preferably 100-
It is 1,000 ppm.

The benzoic acid derivative having a hydroxyalkyl group used in the present invention is benzoic acid substituted with a substituent containing a hydroxyalkyl group. The substituent containing a hydroxyalkyl group may be any as long as it contains a hydroxyalkyl group, for example, an aryl group, a heterocyclic group may be contained, an ether group,
It may have a functional group such as an ester group, a carbonyl group, a thioether group, a sulfoxide group, a sulfonyl group, and an amide group. The hydroxyalkyl group may be substituted with a substituent, and examples thereof include an alkoxy group, an alkyl group, an alkoxycarbonyl group and a halogen atom. The alkoxy group, alkyl group and alkoxycarbonyl group each preferably have 1 to 20 carbon atoms, and more preferably 1 to 10 carbon atoms. The benzoic acid substituted with a substituent containing a hydroxyalkyl group may be substituted with another substituent, and examples thereof include an alkoxy group, an alkyl group, an alkoxycarbonyl group, a nitro group and a halogen atom. The alkoxy group, alkyl group and alkoxycarbonyl group preferably have 1 to 20 carbon atoms, and more preferably 1 carbon atom.
It is 10 pieces.

As the compound used in the present invention, those represented by the general formula (1) are preferable. General formula (1)

[0015]

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R represents an alkylene group. X represents an oxygen atom or a sulfur atom.

The general formula (1) will be described in more detail below. The alkylene group represented by R may be unsubstituted or substituted and has 2 to 30 carbon atoms, preferably 2 to 20 carbon atoms. For example, an unsubstituted alkylene group (for example, ethylene, propylene, butylene, pentylene, Hexylene, heptylene, octylene, nonylene, decylene, 2-ethylbutylene, 3-ethylbutylene), substituted alkylene groups (substituents include, for example, acylamino groups, alkoxy groups, vinyl groups, phenyl groups, acyloxy groups, alkylthio groups, alkoxy groups). Examples thereof include a carbonyl group, an acyl group and a halogen atom. Among these, an acylamino group, an alkoxy group, an acyloxy group,
The alkylthio group, alkoxycarbonyl group, and acyl group each preferably have 1 to 20 carbon atoms, and more preferably 1 to 10 carbon atoms. More specifically, for example, 3-methoxybutylene, 2
-Acetoxypropylene, 2-methylthiobutylene, 4
-Methoxycarbonylhexylene, 3-acetylbutylene, 5-chlorohexylene). Further, the carbon atom of the alkylene group may be replaced with another atom,
For example, oxygen atom (for example, 2-ethyleneoxyethylene), sulfur atom (for example, 2-ethylenethioethylene)
Is mentioned. Further, X may be substituted at any position on the aromatic ring. Specific examples of the compound used in the present invention and the compound obtained in the present invention are shown below. However, the scope of the present invention is not limited to these. Q =
H is a compound represented by the general formula (1) of the present invention,
Others are target ester compounds.

[0018]

[Chemical 4]

[0019]

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[0020]

[Chemical 6]

[0021]

[Chemical 7]

[0022]

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[0023]

[Chemical 9]

[0024]

[Chemical 10]

[0025]

[Chemical 11]

[0026]

[Chemical 12]

[0027]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. Example 1 Synthesis of No. 21 Acrylic acid 140g (20mo
l), sulfuric acid 0.98 g (0.01 mol), hydroquinone monomethyl ether 0.50 g and No. 3 21.0 g
(1 mol) was charged and reacted at 65 ° C. for 7 hours. After cooling, the reaction solution was poured into 500 ml of water and the obtained crystals were recrystallized with an acetone / water solvent to give No. 21 21.9 g (83
%) Was obtained. Identification data of No. 21 ¹ H-NMR (CDCl ₃ ) δ: 8.1 (d, 2H), 6.9 (d, 2H), 6.4 (d, 1H),
6.1 (dd, 1H), 5.8 (d, 1H), 4.2 (t, 2H), 4.0 (t, 2H), 1.6-
1.9 (m, 4H) Melting point: 120-122 ° C

Example 2 Synthesis of No. 21 Reaction was carried out at 65 ° C. for 7 hours in the same manner as in Example 1, and then 65
The water-acrylic acid mixture was removed over 2 hours at reduced pressure at ℃. After cooling, the reaction mixture was poured into 500 ml of water and the precipitated crystals were filtered under reduced pressure and washed with water. After air drying, No. 21 2
Obtained 5.1 g (95%).

Example 3 Synthesis of No. 22 Using No. 4, the same reaction as in Example 2 was carried out.
26.4 g (95%) were obtained. Identification data of No. 22 ¹ H-NMR (CDCl ₃ ) δ: 8.1 (d, 2H), 6.9 (d, 2H), 6.4 (d, 1H),
6.1 (dd, 1H), 5.8 (d, 1H), 4.2 (t, 2H), 4.0 (t, 2H), 1.6-
1.9 (m, 4H), 1.4-1.6 (m, 2H) Phase transition temperature: Crystal phase-99 ° C-Liquid crystal phase-112 ° C-Isotropic liquid

Example 4 Synthesis of No. 23 Using No. 5, the same reaction as in Example 2 was carried out.
27.4 g (94%) were obtained. Identification data of No. 23 ¹ H-NMR (CDCl ₃ ) δ: 8.1 (d, 2H), 6.9 (d, 2H), 6.4 (d, 1H),
6.1 (dd, 1H), 5.8 (d, 1H), 4.2 (t, 2H), 4.0 (t, 2H), 1.6-
1.9 (m, 4H), 1.4-1.6 (m, 4H) Phase transition temperature: Crystal phase-89 ℃ -Liquid crystal phase-113 ℃ -Isotropic liquid

Example 5 Synthesis of No.25 Using No.7, the reaction was carried out in the same manner as in Example No.25.
30.4 g (95%) was obtained. Identification data of No. 25 ¹ H-NMR (CDCl ₃ ) δ: 8.1 (d, 2H), 6.9 (d, 2H), 6.4 (d, 1H),
6.1 (dd, 1H), 5.8 (d, 1H), 4.2 (t, 2H), 4.0 (t, 2H), 1.6-
1.9 (m, 4H), 1.4-1.6 (m, 8H) Phase transition temperature: Crystal phase-75 ℃ -Liquid crystal phase-112 ℃ -Isotropic liquid

Example 6 Synthesis of No.26 No.26 was carried out in the same manner as in Example 2 using No.8.
31.4 g (94%) were obtained. Identification data of No. 26 ¹ H-NMR (CDCl ₃ ) δ: 8.1 (d, 2H), 6.9 (d, 2H), 6.4 (d, 2H),
6.1 (dd, 1H), 5.8 (d, 1H), 4.2 (t, 2H), 4.0 (t, 2H), 1.6-
1.9 (m, 4H), 1.3-1.6 (m, 10H) Phase transition temperature: Crystal phase-99 ° C-Liquid crystal phase-115 ° C-Isotropic liquid

Example 7 Synthesis of No. 41 Using No. 5 and methacrylic acid, the reaction was carried out in the same manner as in Example 2 to obtain 26.5 g (96%) of No. 41. Identification data of No. 41 ¹ H-NMR (CDCl ₃ ) δ: 8.1 (d, 2H), 6.9 (d, 2H), 6.1 (s, 1H),
5.5 (s, 1H), 4.2 (t, 2H), 4.0 (t, 2H), 1.9 (s, 3H), 1.6-1.
9 (m, 4H), 1.4-1.6 (m, 4H) Phase transition temperature: Crystal phase-65 ° C-Liquid crystal phase-100 ° C-Isotropic liquid

Example 8 Synthesis of No. 62 No. 62 was carried out in the same manner as in Example 2 using No. 56.
25.8 g (92%) was obtained. Identification data of No. 62 ¹ H-NMR (CDCl ₃ ) δ: 7.9 (d, 2H), 7.0 (d, 2H), 6.4 (d, 1H),
6.2 (dd, 1H), 5.9 (d, 1H), 4.3 (t, 2H), 4.2 (t, 2H), 3.8
(t, 2H), 3.7 (t, 2H) Melting point: 156-158 ° C

Comparative Example 1 Synthesis of No. 21 (when toluene is used as azeotropic solvent) Acrylic acid 140 g (20 mol) was added to a 500 ml round bottom flask.
l), paratoluenesulfonic acid 1.0 g, hydroquinone monomethyl ether 0.50 g, No. 3 21.0 g
(1.0 mol) and 100 ml of toluene were charged, and the reaction was carried out at a reaction temperature of 120 ° C. for 1 hour. The water generated by the esterification was removed from the reaction system by azeotropic distillation with toluene. The toluene separated from water was returned to the reaction system. After the reaction, a large amount of white insoluble matter, which seems to be a polymer, was attached to the flask. Yield of No. 21: 76% Comparative Example 2 Synthesis of No. 21 (when hexane was used as an azeotropic solvent) Acrylic acid 140 g (20 mol) was added to a 500 ml round bottom flask.
l), paratoluenesulfonic acid 1.0 g, hydroquinone monomethyl ether 0.50 g, No. 3 21.0 g
(1.0 mol) and 100 ml of n-hexane were charged, and the reaction was carried out at a reaction temperature of 80 ° C. for 6 hours. Water generated by the esterification was removed from the reaction system by azeotropic distillation with n-hexane. The n-hexane separated from water was returned to the reaction system. No. 21 crystals that did not dissolve remained in the reaction system. Yield of No. 21: 23% Comparative Example 3 Synthesis of No. 21 (when acrylic acid chloride is used) A report of DJ Broer et al. [Makromol. Chem, vol. 2255 (1989)
] The synthesis was performed according to the synthetic method described in. N
Yield of o.21: 83% Comparative Example 4 Synthesis of No. 21 (when using equal amount of acrylic acid) Acrylic acid 7.0 g (1.0
mol), paratoluenesulfonic acid 1.0 g, hydroquinone monomethyl ether 0.50 g, No.3 21.0 g
(1.0 mol) and 100 ml of chloroform were charged, and the reaction was carried out at a reaction temperature of 65 ° C. for 12 hours. Water generated by esterification was removed from the reaction system by azeotropic distillation with chloroform. Chloroform separated from water was returned to the reaction system. Yield of No. 21: 75% The above results are shown in Table 1. The selectivity of the product was determined by HPLC (eluent: THF / H ₂ O = 50/50, detection wavelength: 254 nm) by sampling the reaction solution.

[0036]

[Table 1]

According to Table 1, in the present invention, the selectivity of the desired product is good and the isolation yield is also good. On the other hand, in Comparative Examples 1 and 2 in which toluene and n-hexane were used as the azeotropic solvent, the isolation yield was lowered due to polymerization and the solubility of the hydroxy compound as a raw material. In addition, Comparative Example 3 using acrylic acid chloride is inferior to the present invention in terms of the selectivity of the target product and the amount of by-products. Then, in Comparative Example 4 in which an equal amount of acrylic acid was used, an increase in by-products derived from dimerization was observed, and the yield of the target product also decreased accordingly.

[0038]

INDUSTRIAL APPLICABILITY The present invention does not use chloroform or benzene which is an azeotropic solvent with highly toxic water when producing a (meth) acrylic acid ester of a benzoic acid derivative having a hydroxyalkyl group, and It is possible to provide a production method which does not use acrylic acid chloride and has strong tearing property, is difficult to handle, and produces a by-product in the reaction.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07C 323/62 7419-4H C07C 323/62 // C07B 61/00 300 C07B 61/00 300

Claims (3)

[Claims] 1. A method for producing an acrylic acid ester or methacrylic acid ester of a hydroxy group from acrylic acid or methacrylic acid and a benzoic acid derivative having a hydroxyalkyl group in the presence of an acid catalyst, wherein a solvent for the benzoic acid derivative is used. A method for producing an ester, characterized in that only acrylic acid or methacrylic acid is used as the ester. 2. The method for producing an ester according to claim 1, wherein the benzoic acid derivative having a hydroxyalkyl group is a compound represented by the following general formula (1). General formula (1) R represents an alkylene group. X represents an oxygen atom or a sulfur atom. 3. The amount of acrylic acid or methacrylic acid used is 1.0 in terms of molar ratio with respect to 1 mol of the benzoic acid derivative.
The method according to claim 1, wherein the method is at least 100 times and at least 200 times.