Dihydroxy compound and method for producing same

Abstract

To provide: a novel dihydroxy compound having high purity, no coloration, and a high refractive index; and a production method thereof.SOLUTION: Provided is a dihydroxy compound represented by the following formula (1). (In the formula, Z1 is a heterocyclic group containing a sulfur atom; L1 is an alkylene group having 1-15 carbon atoms; m1 is an integer of 0-5; and n1 is an integer of 1-4.)SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a dihydroxy compound and a method for producing the same. [Background technology]

[0002] Plastic optical materials are lighter than inorganic materials such as glass, less likely to break, and easier to process, and are expected to be applied to eyeglass lenses, camera lenses, industrial lenses, retardation compensation plates for liquid crystal displays, optical fibers, and the like. However, there are many problems to be solved with current plastic optical materials. For example, in lens applications, properties such as a high refractive index are required, but the refractive index of plastic lenses currently in practical use does not reach the refractive index of high refractive index glass materials, and further performance improvement is required. Under such a background, it has been shown that dihydroxy compounds containing dinaphthothiophene have a rare high refractive index as an organic compound (Patent Document 1). However, as described in the examples, the compound is colored, and there are problems with using it as a raw material for thermoplastic resins that are the material for lenses. In addition, there are problems such as the need for many manufacturing steps to obtain the compound, the need for raw materials that are hazardous to fire or explode, and the need for high-temperature reactions of about 250°C. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-196288 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a novel dihydroxy compound which is highly pure, colorless and has a high refractive index, and a method for producing the same. [Means for solving the problem]

[0005] The present inventors have found that the above problems can be solved by the present invention having the following aspects. Aspect 1 A dihydroxy compound represented by the following formula (1):

[0006] [ka] (In the formula, Z1 is a heterocyclic group containing a sulfur atom, L1 is an alkylene group having 1 to 15 carbon atoms, m1 is an integer of 0 to 5, and n1 is an integer of 1 to 4.)

[0007] Aspect 2 The dihydroxy compound according to embodiment 1, represented by the following formula (2):

[0008] [ka] (In the formula, Z1, L1, and m1 are the same as those in formula (1).)

[0009] Aspect 3 The dihydroxy compound according to embodiment 1 or 2, represented by the following formula (3):

[0010] [ka] (In the formula, Z2 is a dibenzothiophenyl group, and L1 and m1 are the same as those in formula (1).)

[0011] Aspect 4 The dihydroxy compound according to any one of aspects 1 to 3, represented by the following formula (4):

[0012] [ka] (In the formula, L1 and m1 are the same as those in formula (1).)

[0013] Aspect 5 The dihydroxy compound according to any one of aspects 1 to 4, wherein m1 in the formula is 0. Aspect 6 The dihydroxy compound according to any one of aspects 1 to 5, which has a refractive index of 1.70 or more. Aspect 7 A method for producing a dihydroxy compound according to embodiment 1, comprising reacting a diol represented by the following formula (5) with a boronic acid represented by the following formula (6) in a reaction solvent in the presence of a base and a palladium catalyst:

[0014] [ka] (In the formula, X1 is a halogen atom, L1 is an alkylene group having 1 to 15 carbon atoms, m1 is an integer of 0 to 5, and n1 is an integer of 1 to 4.)

[0015] [ka] (In the formula, Y1 is a heterocyclic group containing a sulfur atom.)

[0016] Aspect 8 A method for producing a dihydroxy compound according to embodiment 7, wherein the diol represented by the formula (5) is represented by the following formula (7):

[0017] [ka] Effect of the Invention

[0018] According to the present invention, it is possible to provide a dihydroxy compound containing thiophene that is highly pure, colorless, and has a high refractive index, and also to provide a production method for obtaining the dihydroxy compound in a single reaction step. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing an NMR chart of the dihydroxy compound obtained in Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <Dihydroxy compounds> The novel dihydroxy compound of the present invention is represented by the following formula (1).

[0021] [ka] (In the formula, Z1 is a heterocyclic group containing a sulfur atom, L1 is an alkylene group having 1 to 15 carbon atoms, m1 is an integer of 0 to 5, and n1 is an integer of 1 to 4.)

[0022] In formula (1), n1 is an integer of 1 to 4, preferably an integer of 1 to 2, and particularly preferably 2. That is, among the dihydroxy compounds represented by formula (1), the dihydroxy compounds represented by the following formula (2) are particularly preferred.

[0023] [ka] (In the formula, Z1, L1, and m1 are the same as those in formula (1).)

[0024] Z1 in formula (1) and formula (2) is a heterocyclic group containing a sulfur atom, such as a thienyl group, a benzothiophenyl group, a dibenzothiophenyl group, etc., and the dibenzothiophenyl group is particularly preferred. That is, among the dihydroxy compounds represented by formula (2), the dihydroxy compounds represented by the following formula (3) are particularly preferred.

[0025] [ka] (In the formula, Z2 is a dibenzothiophenyl group, and L1 and m1 are the same as those in formula (1).)

[0026] Z2 in formula (3) is a dibenzothiophenyl group, and examples thereof include a dibenzothiophene-1-yl group, a dibenzothiophene-2-yl group, a dibenzothiophene-3-yl group, and a dibenzothiophene-4-yl group, and the dibenzothiophene-2-yl group is particularly preferred. That is, among the dihydroxy compounds represented by formula (3), the dihydroxy compounds represented by the following formula (4) are particularly preferred.

[0027] [ka] (In the formula, L1 and m1 are the same as those in formula (1).)

[0028] L1 in the formulas (1) to (4) is an alkylene group having 1 to 15 carbon atoms, preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms, and particularly preferably an ethylene group. In the formulas (1) to (4), m1 is an integer of 0 to 5, preferably 0 or 1, and more preferably 0.

[0029] The dihydroxy compound of the present invention has an HPLC purity, as measured by HPLC, of ​​preferably 90 area % or more, more preferably 95 area % or more, and even more preferably 98 area % or more.

[0030] The refractive index of the dihydroxy compound of the present invention is preferably 1.70 or more, more preferably 1.71 or more, and even more preferably 1.72 or more. The refractive index was determined by dissolving the dihydroxy compound in dimethyl sulfoxide to prepare a solution of a predetermined concentration, measuring the D-line refractive index at 25°C of the solution of each concentration using an ATAGO DR-M2 Abbe refractometer, and extrapolating the measurement results of each concentration to a concentration of 100% to obtain the refractive index (nD) of the compound.

[0031] <Method of producing dihydroxy compound> The dihydroxy compound of the present invention can be produced by reacting a diol represented by the following formula (5) with a boronic acid represented by the following formula (6) in a reaction solvent in the presence of a base and a palladium catalyst, to produce the dihydroxy compound represented by the above formula (1).

[0032] [ka]

[0033] (In the formula, X1 is a halogen atom, L1 is an alkylene group having 1 to 15 carbon atoms, m1 is an integer of 0 to 5, and n1 is an integer of 1 to 4.)

[0034] [ka] (In the formula, Y1 is a heterocyclic group containing a sulfur atom.)

[0035] X1 in formula (5) is a halogen atom, preferably a chlorine atom or a bromine atom, more preferably a bromine atom.

[0036] Specific examples of the diols represented by formula (5) include 2,2-bis(3-chloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, 2,2-bis(3-bromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 2,2-bis(3-iodo-4-hydroxyphenyl)propane, and 2,2-bis(3,5-diiodo-4-hydroxyphenyl)propane. More preferred are 2,2-bis(3-bromo-4-hydroxyphenyl)propane and 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane. In particular, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane represented by formula (7) is preferred. These diols may be used alone or in combination of two or more, and may be selected arbitrarily according to the purpose.

[0037] [ka]

[0038] Specific examples of the boronic acids represented by the formula (6) include 2-thiopheneboronic acid, 3-thiopheneboronic acid, benzothiophene-2-boronic acid, benzothiophene-3-boronic acid, benzothiophene-4-boronic acid, benzothiophene-5-boronic acid, benzothiophene-6-boronic acid, benzothiophene-7-boronic acid, dibenzothiophene-2-boronic acid, dibenzothiophene-3-boronic acid, and dibenzothiophene-4-boronic acid. Dibenzothiophene-2-boronic acid, dibenzothiophene-3-boronic acid, and dibenzothiophene-4-boronic acid are preferred, and dibenzothiophene-2-boronic acid is particularly preferred. In addition, the boronic acids also include boronic acid esters and boronic acid anhydrides of these compounds. These boronic acids may be used alone or in a mixture of two or more, and can be selected arbitrarily according to the purpose.

[0039] The ratio of the boronic acid represented by the formula (6) used as a raw material is preferably 2.0 to 6.0 mol, more preferably 3.0 to 5.0 mol, and further preferably 4.0 to 4.5 mol, per 1 mol of the diol compound represented by the formula (5).

[0040] Examples of the base used in the production method of the present invention include hydroxides such as sodium hydroxide and potassium hydroxide, carbonates such as sodium carbonate (Na2CO3), potassium carbonate (K2CO3), and cesium carbonate (Cs2CO3), acetates such as sodium acetate and potassium acetate, phosphates such as sodium phosphate (Na3PO4) and potassium phosphate (K3PO4), and other inorganic salts, as well as organic salts such as triethylamines, pyridine, morpholine, quinoline, piperidine, anilines, and ammonium salts such as tetra-n-butylammonium acetate. Among these, carbonates are preferably used, and potassium carbonate and / or sodium carbonate are preferred. Such bases may be used alone or in combination of two or more.

[0041] The amount of the base used is not particularly limited, but is preferably 1 to 30 equivalents, more preferably 1 to 10 equivalents, per mole of the boronic acid.

[0042] The palladium catalyst used in the production method of the present invention is preferably a palladium compound used in Suzuki coupling, such as tetrakis(triphenylphosphine)palladium, bis(triphenylphosphine)palladium dichloride, palladium acetate, tris(dibenzylideneacetone)dipalladium, bis(dibenzylideneacetone)palladium, bis[4-(N,N-dimethylamino)phenyl]di-tert-butylphosphinepalladium dichloride, bis(di-tert-butylprenylphosphine)palladium dichloride, bis(di-tert-crotylphosphine)palladium dichloride, and palladium catalysts represented by Pd / SiO2. Among them, tetrakis(triphenylphosphine)palladium is preferred. These palladium catalysts may be used alone or in combination of two or more.

[0043] The amount of the catalyst used is not particularly limited, but is preferably 0.1 to 50 mmol, more preferably 0.5 to 30 mmol, calculated as palladium metal atom, per 1 mol of the diol compound represented by the formula (5).

[0044] The reaction solvent used in the production method of the present invention is not particularly limited, and for example, aromatic hydrocarbon solvents such as toluene and xylene and alcohols such as methanol, ethanol, isopropyl alcohol, and n-butanol can be used alone or in combination. Aromatic hydrocarbon solvents are high boiling point solvents, so the reaction temperature can be set high, and alcohols have good affinity with water and good reactivity, so they are preferably used. Such solvents may be used alone or in combination of two or more. Furthermore, aprotic solvents such as N,N-dimethylformamide or N,N-dimethylacetamide, and halobenzenes such as o-dichlorobenzene can also be used. Such solvents may be used alone or in combination of two or more. In the present invention, a mixed solvent of toluene and ethanol is more preferable.

[0045] The amount of the reaction solvent used is not particularly limited, but is preferably 0.1 times by weight or more, more preferably 0.5 to 100 times by weight, and even more preferably 1 to 50 times by weight, relative to 1 mole of the diol compound represented by the formula (5).

[0046] In the case of a mixed solvent of toluene and ethanol which is particularly preferably used as the reaction solvent, the amount of toluene used is preferably 0.1 times by weight or more, more preferably 0.5 to 100 times by weight, and even more preferably 1 to 50 times by weight, relative to 1 mole of the diol compound represented by the formula (5). The amount of ethanol used is preferably 0.1 to 50 times by weight, and more preferably 1 to 20 times by weight, relative to 1 mole of the compound represented by the formula (5).

[0047] In the production method of the present invention, the reaction temperature varies depending on the types of raw materials and solvent used, but is preferably 50 to 150° C., more preferably 60 to 130° C., and further preferably 70 to 120° C. The reaction can be monitored by an analytical means such as liquid chromatography.

[0048] In the production method of the present invention, the reaction mixture after the completion of the reaction usually contains unreacted boronic acids, bases, catalysts, by-products, etc., in addition to the dihydroxy compound represented by the formula (1) produced. Therefore, it can be separated and purified by a conventional method, such as filtration, concentration, extraction, crystallization, recrystallization, reprecipitation, activated carbon treatment or a similar metal removal treatment, column chromatography, or a combination of these. For example, it is preferable to remove boronic acids by a conventional method (such as a method of adding an alkaline aqueous solution to form a water-soluble complex), remove palladium compounds by activated carbon treatment or a similar metal removal treatment, add a recrystallization solvent, cool, recrystallize, and then filter and separate to purify. EXAMPLES

[0049] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples as long as it does not depart from the gist of the present invention. In the examples, various measurements were carried out as follows. (1) HPLC measurement Measurement was performed using a Hitachi high performance liquid chromatograph L-2350 under the measurement conditions shown in Table 1. In the examples, unless otherwise specified, % is an area percentage value corrected by excluding the solvent in HPLC.

[0050] [Table 1]

[0051] (2)NMR measurement The compounds obtained in the examples were dissolved in deuterated chloroform and measured using a JNM-AL400 (400 MHz) manufactured by JEOL Ltd. (3) Refractive index (nD) The dihydroxy compound obtained in the examples was dissolved in dimethyl sulfoxide to prepare solutions of a predetermined concentration, and the refractive index of the solutions of each concentration was measured at 25° C. using an ATAGO DR-M2 Abbe refractometer to measure the D-line refractive index. The value obtained by extrapolating the measurement results of each concentration to a concentration of 100% was taken as the refractive index (nD) of the compound obtained in the examples.

[0052] [Example 1] In a nitrogen atmosphere, 3.00g (6mmol) of tetrabromobisphenol A (hereinafter sometimes abbreviated as TBA), 2.77g (12mmol) of dibenzothiophene-2-boronic acid, 0.06g (0.06mmol) of tetrakis(triphenylphosphine)palladium, 12ml of 2M potassium carbonate aqueous solution, 25ml of toluene, and 8ml of ethanol were added to a flask equipped with a stirrer, a cooler, and a thermometer, and reacted at 80°C for 4 hours. Then, 0.06g (0.06mmol) of tetrakis(triphenylphosphine)palladium and 2.77g (12mmol) of dibenzothiophene-2-boronic acid were added, and reacted at 80°C for 4 hours. After the reaction was completed, the reaction solution was diluted with ethyl acetate, transferred to a separatory funnel, and washed with distilled water until it became neutral. Then, hexane was added to the organic layer to recrystallize it. The obtained crystals were collected and dried under reduced pressure to obtain 2.1 g of crude product of 2,2-bis(3,5-di(dibenzothiophen-2-yl)-4-hydroxyphenyl)propane (hereinafter sometimes abbreviated as TDBTA) represented by the following formula (8) (purity 71%). The crude product was purified by column (eluent: ethyl acetate:hexane = 1:3), and the obtained eluate was concentrated and recrystallized. The obtained crystals were collected and dried under reduced pressure to obtain 0.6 g of white crystal of TDBTA (purity 98.21%). The refractive index of TDBTA was 1.727.

[0053] [ka]

[0054] [Comparative Example 1] 2,2-bis(3,5-diphenyl-4-hydroxyphenyl)propane represented by the following formula (9) was obtained in the same manner as in Example 1, except that dibenzothiophene-2-boronic acid was changed to phenylboronic acid and the amount of phenylboronic acid added was 2.96 g (24 mmol). The refractive index of the compound was 1.65.

[0055] [ka]

[0056] The novel dihydroxy compound obtained in Example 1 has a high refractive index, high purity, and excellent hue. Moreover, such a dihydroxy compound can be produced in a single reaction step, making it industrially useful. [Industrial Applicability]

[0057] The novel dihydroxy compound obtained in the present invention is suitable as a monomer for forming a resin constituting an optical member such as an optical lens or an optical film.

Claims

1. A dihydroxy compound represented by the following formula (4): 【Chemistry 1】 (In the formula, L １ is an alkylene group having 1 to 15 carbon atoms; m １ is an integer from 0 to 5.

2. In the above formula, m １ The dihydroxy compound according to claim 1, wherein

3. 3. The dihydroxy compound according to claim 1, having a refractive index of 1.70 or more.

4. The method for producing a dihydroxy compound according to claim 1, comprising reacting a diol represented by the following formula (5) with a boronic acid represented by the following formula (6) in a reaction solvent in the presence of a base and a palladium catalyst: 【Chemistry 2】 (In the formula, X １ is a halogen atom, L １ is an alkylene group having 1 to 15 carbon atoms; m １ is an integer from 0 to 5, n １ is an integer equal to 2.) 【Chemistry 3】 (In the formula, Y １ is a dibenzothiophenyl group.)

5. The method for producing a dihydroxy compound according to claim 4, wherein the diol represented by the formula (5) is represented by the following formula (7): 【Chemistry 4】

Images