JPH1112219A - Partial alkylation of polyhydroxybenzophenone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound that is useful as an ultraviolet absorber for polymers and cosmetics by allowing a polyhydroxybenzophenone with an alkyl halide in the presence of an alkali to effect partial alkylation and facilitate the recovery of the solvents and the separation of inorganic salts. SOLUTION: A polyhydroxybenzophenone of formula I (R, R1 and R2 are each H, alkyl, hydroxy) is allowed to react with an alkyl halide in the presence of a quaternary ammonium salt of formula II (R6 -R9 are each an alkyl; X is Cl, Br), a tertiary amine as tributylamine, triethylamine, and a halogenated alkali metal as potassium iodide or potassium bromide in a hydrocarbon solvent as toluene, xylene or heptane in 0.7-3-fold volume of the reactants to effect partial alkylation thereby forming the objective benzophenone of formula III (R3 is an alkyl; R4 and R5 are each H, an alkyl, a halogen and the like).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for partially alkylating polyhydroxybenzophenones.

[0002]

2. Description of the Related Art 2-Hydroxy-4-alkoxybenzophenones are extremely excellent ultraviolet absorbers used for polymers and cosmetics, and a number of production methods have been disclosed before the present application. Many of the production methods involve a method of reacting a polyhydroxybenzophenone of the above formula (1) with an alkyl halide in the presence of an alkali metal to perform partial alkylation. This reaction is usually carried out in a solvent. As the solvent, higher alcohols, acetone, dimethylformamide and the like are known, but various reactions such as a low reaction rate, a low yield, and a reaction of the solvent itself are performed. Is not satisfactory. Further, a method using such an ethylene glycol or diethylene glycol alkyl ether as a solvent (Japanese Patent Laid-Open No. 54-44641) and a method using tetrafurfuryl alcohol as a solvent (Japanese Patent Publication No. 54-11302) which do not have such a drawback have been proposed. However, all are polar solvents that have a high boiling point and are easily soluble in water.
However, since these solvents have a high boiling point, after completion of the reaction,
Even if it is recovered by vacuum distillation, complete recovery is impossible, and it remains in the filtrate after crystallization and dissolves in the wastewater. Further, each of the polar solvents as described above has a large COD load, particularly a BOD load, and requires a great deal of labor and cost for drainage treatment.

[0003]

SUMMARY OF THE INVENTION According to the present invention, it is easy to recover a solvent used in the production and to separate inorganic salts and the like produced as a by-product in the production, and to use ultraviolet rays for polymers and cosmetics. It is an object of the present invention to provide a method for the partial alkylation of the polyhydroxybenzophenones, which can provide sufficient quality as an absorbent.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have produced polybenzobenzophenones represented by the following formula (1) with an alkyl halide in the presence of an alkali to produce benzophenones represented by the following formula (2). In the method, focusing on the fact that the solvent has a large effect on the reaction, as a result of intensive research, the reaction overwhelmed the technical common knowledge before the present application that it was difficult for the reaction to proceed in a non-polar solvent. Add a predetermined amount of a quaternary ammonium salt (A), a tertiary amine and an alkali metal halide (B) or the above (A) and (B) to a hydrocarbon solvent as a polar solvent, as shown below. As a result, not only can the disadvantages of the solvent used in the prior art be eliminated, but also the benzophenones represented by the following formula (2) can be obtained with high quality, and the present invention has been achieved. It could be.

Embedded image

That is, in the present invention, a reaction solvent in which a predetermined amount of a quaternary ammonium salt or a tertiary amine and an alkali metal halide is added to a hydrocarbon solvent which is a non-polar solvent is used as a reaction solvent for the reaction. Thereby, the reaction proceeds smoothly, and after the reaction, adding water,
A simple separation operation of separating the aqueous layer and taking out the target substance from the solvent layer yields the target substance of the above formula (2), and since there is no water-soluble solvent in the aqueous layer, COD, B
Since the OD load is extremely small, the drainage processing can be performed very easily. Further, not only is it easy to recover the solvent and separate the inorganic salt, but also when removing the aqueous layer of the inorganic salt, it is possible to remove the water-soluble impurity coloring matter, so that the benzophenones of the target product obtained by the conventional method can be removed. The quality is good.

The method for producing the polyhydroxybenzophenones represented by the formula (1) used as a starting compound in the present invention includes those represented by the following reaction formulas (P) and (Q). The polyhydroxybenzophenones produced by the reaction formula (P) are of high quality, while the polyhydroxybenzophenones produced by the reaction formula (Q) are of low quality, and the high-quality polyhydroxybenzophenones are When used as a starting compound of the reaction type employed in the present invention, the obtained product does not cause any problem.However, when the low-quality polyhydroxybenzophenones are used, the obtained product is usually used. Is severely colored and requires a great deal of labor for purification. However, according to the present invention, by using hydrocarbons as a solvent, even when the low-quality polyhydroxybenzophenones are used, the same as when the high-quality polyhydroxybenzophenones are used. Benzophenones of the formula (2) having no problem in terms of coloring and the like can be produced.

[0007]

Embedded image [In the above formula, the definitions of R, R ₁ and R ₂ are the same as the definition of the above formula (1). ]

Hereinafter, the present invention will be described in more detail. The reaction temperature of the production method of the present invention is usually 80 to 80, as described below.
It is about 130 ° C. Examples of the hydrocarbon solvent used in the present invention include toluene, xylene, heptane, octane, etc., and since compounds having a boiling point or water and an azeotropic point with water near the reaction temperature are preferable, among them, toluene, heptane, etc. Particularly preferred. The hydrocarbon solvents may be used as a mixed solvent by mixing them. The amount of the hydrocarbon solvent used varies depending on the type of the hydrocarbon solvent used, but is usually 0.7 to 3 with respect to the polyhydroxybenzophenone of the formula (1).
It is about twice as much.

The quaternary ammonium salt (A) used in the present invention is not particularly limited as long as the intended object of the present invention can be achieved, and for example, those represented by the following formula (3) Specific examples thereof include monoalkyltrimethylammonium chloride (Arcard T-50, a product name of Lion Corporation), tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium iodide, tetrabutylammonium bromide, and tetrabutylammonium hydrochloride. Oxide, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride and the like can be mentioned, but ARKARD T-50, tetrabutylammonium bromide, benzyltributy Ammonium chloride are preferred. Further, the quaternary ammonium salt (A) may be used in combination with an alkali metal halide as in the case of the tertiary amine and the alkali metal halide (B).

Embedded image In the above formula, R ₆ , R ₇ , R ₈ and R ₉ are the same or different alkyl, or R ₆ is phenyl or benzyl, and R ₇ , R ₈ and R ₉ are the same or different. Is also a good alkyl. X is chlorine, bromine, iodine or hydroxy.

The amount of the quaternary ammonium salt to be used varies depending on the kind of the quaternary ammonium salt, but is usually represented by the above formula (1).
1 to 6% by weight based on polyhydroxybenzophenones
It is about.

The tertiary amine used in the present invention includes:
There is no particular limitation as long as the intended object of the present invention can be achieved, and examples thereof include triethylamine and tributylamine.

As the alkali metal halide as another catalyst component, potassium iodide, potassium bromide, sodium iodide, sodium bromide and the like are used. The amount of the tertiary amine used depends on the type of the tertiary amine used, but is usually about 1 to 6% by weight based on the polyhydroxybenzophenone of the formula (1). The amount of the alkali metal halide used also varies depending on the type used, but is usually about 0.5 to 3% by weight based on the polyhydroxybenzophenones of the formula (1).

Examples of the polyhydroxybenzophenones represented by the formula (1) used as a starting compound in the method for producing benzophenones of the present invention include the following. 2,4-dihydroxybenzophenone 2,2 ', 4-trihydroxybenzophenone 2,2', 4-trihydroxy-4'-chlorobenzophenone 2,4-dihydroxy-4'-tert-butylbenzophenone 2,4-dihydroxy- 4'-methylbenzophenone 2,4-dihydroxy-4'-chlorobenzophenone 2,4-dihydroxy-3 ', 5'-dimethylbenzophenone 2,2', 4,4'-tetrahydroxybenzophenone 2,4-dihydroxy-2 '-Carboxybenzophenone 2,4-dihydroxy-2'-methoxybenzophenone

The alkyl halide has 1 to 20 carbon atoms, preferably 1 to 18 carbon atoms, and the halides are bromide and chloride.

The reaction of the present invention is preferably carried out in the presence of an alkali component. Examples of the alkali component include sodium carbonate, sodium bicarbonate, potassium carbonate, sodium hydroxide, potassium hydroxide and the like.

The reaction of the present invention is carried out usually at 80 to 160 ° C.
Done in the degree. Water is by-produced with the progress of the reaction, and this water is preferably removed together with the solvent outside the system during the reaction. When the reaction temperature is higher than 110 ° C., it is preferable to use an antioxidant such as dilaurylthiopropionate in combination, since the possibility of discoloration is reduced.

The target compounds of the present invention include, for example, compounds of the following formulas (C) and (D).

Embedded image [In the above formula (2), R = hydroxy, R ₃ = methyl, R ₄ = hydrogen, and R ₅ = hydrogen. ]

[0018]

Embedded image [In the formula (2), R = hydroxy, R ₃ = methyl, R ₄ = hydrogen, and R ₅ = methoxy. ]

[0019]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples.

Example 1 64.05 g (purity 95.5%) of 2,4-dihydroxybenzophenone, n-octyl bromide 59.04
g, toluene 66 g, water 15 g, potassium carbonate 23.9
g, dilauryl thiodipropionate 0.4 g to 2.4
g, Arcard T-50 (trade name: Lion Corporation, monoalkyltrimethylammonium chloride) was added thereto, and the mixture was heated with stirring, and the existing water and water generated during the reaction were removed from the system by azeotropic distillation with toluene. While gradually increasing the temperature
The reaction was carried out at 20 to 125 ° C. until unreacted 2,4-dihydroxybenzophenone became 1% (unreacted detection was the area ratio in liquid chromatography analysis). Water generated during this time was removed outside the system. The time required to complete the reaction was about 9 hours. Next, the reaction solution was cooled to 80 ° C.
After stirring at 75 to 80 ° C. for 15 minutes, the mixture was allowed to stand, and the lower aqueous layer was separated. The amount of toluene in the separated aqueous layer was trace. This water layer should be discarded, but the treatment method is extremely simple as described in the reference example below. The upper toluene layer was added with activated clay (3 g) and filtered while hot to remove a small amount of insoluble components, and then toluene was recovered at normal pressure or reduced pressure.
To completely recover toluene. The remaining amount of toluene was 0.1% or less based on the residue (gas chromatography analysis). 200 ml of isopropyl alcohol was added to the residue, and the mixture was heated to 70 ° C. and cooled to 15 ° C. to give a pale yellow 2-hydroxy-4-
Since octyloxybenzophenone is precipitated, 2-hydroxy-4-octyloxybenzophenone is separated by suction filtration, washed with a small amount of isopropyl alcohol, and dried to yield 82.0 g and 87.98%.
(Melting point 47.4-48.5 ° C) at 2-hydroxy-4-
Octyloxybenzophenone was obtained.

Example 2 64.05 g (purity 95.5%) of 2,4-dihydroxybenzophenone, n-octyl bromide 59.04
g, toluene 66 g, water 15 g, potassium carbonate 23.9
g, dilauryl thiodipropionate 0.4 g, benzyltributylammonium chloride 1.0 g, and potassium iodide 0.6 g, and the mixture was heated with stirring to remove water present and water generated during the reaction with toluene. The temperature was gradually raised while being removed from the system by boiling.
It reacted until it reached 91%. Water generated during this time was removed outside the system. The required time was 18 hours. Thereafter, the same treatment as in Example 1 was carried out to give pale yellow 2-hydroxy-4-octyloxybenzophenone (melting point: 47.6 to 48.5 ° C.).
Was obtained in a yield of 83.6 g and a yield of 89.0%.

Example 3 64.05 g (purity 95.5%) of 2,4-dihydroxybenzophenone, n-octyl bromide 59.04
g, toluene 66 g, water 15 g, potassium carbonate 23.9
g, dilaurylthiodipropionate 0.4 g, tributylamine 1.2 g, and potassium iodide 0.6 g, and the mixture is heated with stirring, and the water present and the water generated during the reaction are azeotropically mixed with toluene. The temperature was gradually increased while removing the solution outside the system.
The reaction was carried out at 0 to 125 ° C. until the unreacted amount became 0.17%. Water generated during this time was removed outside the system. The time required to complete the reaction was 8.5 hours. Thereafter, the same treatment as in Example 1 was carried out to obtain pale yellow 2-hydroxy-4-octyloxybenzophenone (melting point: 47.6 to 48.5 ° C.) in a yield of 87.1 g and a yield of 93.3%. Even in this example, 2.0 g of triethylamine was used instead of 1.2 g of tributylamine, and the same yield and yield were obtained.

Example 4 64.05 g (purity: 95.5%) of 2,4-dihydroxybenzophenone, n-octyl bromide 59.04
g, heptane 55 g, water 15 g, potassium carbonate 23.9
g, dilaurylthiodipropionate 0.4 g, tributylamine 2.6 g, and potassium iodide 0.6 g, and the mixture was heated with stirring, and the water present and the water generated during the reaction were azeotropically mixed with heptane. The temperature was gradually increased while removing it outside the system.
The reaction was carried out at 5 to 120 ° C. until the unreacted amount became 1.2%. The time required to complete the reaction was 14 hours. Next, the mixture was cooled to 70 ° C.
After stirring for 15 minutes at, the mixture was allowed to stand, and the lower aqueous layer was separated. The amount of heptane in the separated aqueous layer was trace. The upper heptane layer was added with 3 g of activated clay and filtered while hot to remove a small amount of insoluble components, and then heptane was recovered at normal pressure or reduced pressure. . The remaining amount of heptane was 0.05% based on the residue. After adding 200 ml of isopropyl alcohol to the residue after heptane recovery, heating to 70 ° C. and cooling to 15 ° C., a light yellow 2-hydroxy-4-octyloxybenzophenone precipitates, which is separated by suction filtration. Wash with isopropyl alcohol and dry,
2-hydroxy-4-octyloxybenzophenone (melting point 47.0) with a yield of 75.5 g and a yield of 81.0%.
48.5 ° C).

Example 5 64.05 g (purity 95.5%) of 2,4-dihydroxybenzophenone, 78.2 g of n-dodecyl bromide,
80 g of mixed xylene, 15 g of water, 23.9 potassium carbonate
g, dilauryl thiodipropionate 0.4 g, benzyltributylammonium chloride 1.5 g and potassium iodide 0.6 g were added thereto, and the mixture was heated under stirring to remove water present and water generated during the reaction with xylene. The temperature was gradually raised while being removed from the system by azeotropic distillation, and the reaction was performed at 130 to 135 ° C. until unreacted 2,4-dihydroxybenzophenone became 1.2%. Water generated during this time was removed outside the system. The time required to complete the reaction was 13 hours. Next, the mixture was cooled to 80 ° C.
After stirring for 15 minutes, the mixture was allowed to stand, and the lower aqueous layer was separated. Xylene content in the separated aqueous layer was trace. The upper xylene layer was added with activated clay (3.5 g), filtered while hot to remove a small amount of insoluble components, and xylene was recovered at normal pressure or reduced pressure.
Finally, xylene was completely recovered at 125 to 130 ° C. under a reduced pressure of 30 mmHg. The amount of xylene remaining is 0.1
% Or less. Isopropyl alcohol 20 in the residue
When 0 ml was added, the mixture was heated to 70 ° C. and cooled to 15 ° C., and light yellow 2-hydroxy-4-dodecyloxy-benzophenone was precipitated. .2g
And 2-hydroxy-4-octyloxybenzophenone (melting point 40-43 ° C) was obtained at a yield of 79.0%. In this example, even when 1.5 g of tetraethylammonium chloride was used instead of 1.5 g of benzyltributylammonium chloride, the benzophenone was obtained in exactly the same yield and yield. Further, when 104.6 g of stearyl bromide is used in place of 78.2 g of n-dodecyl bromide in the present example, the yield is 74,000.
2-hydroxy-3-stearyloxybenzophenone (mp 47-50 ° C.) was obtained in 5% and yield 98.5 g.

Example 6 64.05 g (purity 95.5%) of 2,4-dihydroxybenzophenone, 46.8 g of n-octyl chloride,
66 g of toluene, 15 g of water, 23.9 g of potassium carbonate,
0.4 g of dilauryl thiodipropionate and 3.5 g of ARKARD T-50 were added, and the mixture was heated with stirring, and while water existing during the reaction and water generated during the reaction were removed azeotropically with toluene, 120 g was removed. The reaction was carried out at ℃ 125 ° C. for 15 hours. According to the liquid chromatography method, unreacted 2,4-dihydroxybenzophenone was 8%. Thereafter, the same treatment as in Example 1 was carried out to give pale yellow 2-hydroxy-4-octyloxybenzophenone (melting point: 47.0-48.3 ° C.).
9 g was obtained in a yield of 67.5%.

Example 7 64.05 g (purity: 95.5%) of 2,4-dihydroxybenzophenone, 66 g of toluene, 48% sodium hydroxide 2
6.2 g and 3.0 g of ARKARD T-50 were collected in a 500 ml autoclave purged with nitrogen, and 29.8 g of methyl bromide cooled to 0 ° C. was added at a temperature of 4 ° C. or less with stirring, and the temperature was gradually increased to 95%. １００100 ° C. and reacted for 8 hours. After the reaction, 120 ml of water was added and the mixture was added at 75 to 80 ° C for 15 minutes.
After stirring for minutes, the mixture was allowed to stand, and the lower aqueous layer was separated. Thereafter, the toluene layer was treated in the same manner as in Example 1 to give pale yellow 2-hydroxy-4-methoxybenzophenone (melting point: 63 to 64).
° C) in a yield of 80% and a yield of 52.1 g.

Example 8 Example 7 was repeated except that 65.7 g of 2,2 ', 4-trihydroxybenzophenone (purity 100%) was used instead of 64.05 g of 2,4-dihydroxybenzophenone used in Example 7. Perform the same operation as
2'-Dihydroxy-4-methoxybenzophenone (mp 68-70 ° C) was obtained in a yield of 78.0% and a yield of 50.8%.
g.

Example 9 70.3 g of 2,2 ', 4,4'-tetrahydroxybenzophenone, 120 g of toluene, 48% sodium hydroxide 5
2.4 g and 2.2 g of benzyltributylammonium chloride were collected in a 1-liter autoclave in which nitrogen was replaced, and 59.7 g of methyl bromide cooled to 0 ° C. at a temperature of 4 ° C. or less was added under stirring, and the temperature was gradually raised. The temperature was raised to 95 to 100 ° C., and the reaction was performed for 8 hours. After the reaction, 250 ml of water was added, and the mixture was stirred at 75 to 80 ° C. for 15 minutes, allowed to stand, and the lower aqueous layer was separated. Thereafter, the toluene layer was treated in the same manner as in Example 1 to give pale yellow 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (melting point: 134-136 ° C), yield: 71%.
And a yield of 55.6 g.

REFERENCE EXAMPLE The aqueous layer (COD 1500 ppm) produced in Example 1
After adjusting the pH to 3.0 to 3.5 with 2.5% sulfuric acid to remove a small amount of insoluble components, adding 1.2 g of decolorizing carbon and filtering the solution, the solution adjusted to pH 6 to 8 with caustic soda has a COD of 150 p.
pm and BOD were 120 ppm. It was less than the standard value stipulated in Article 9-5 of the Sewerage Law enacted by the Environment Agency (revised 1986 Cabinet Order 159).

[0030]

According to the present invention, it is possible to obtain a partially alkylated polyhydroxybenzophenone having a sufficient quality as a polymer or an ultraviolet absorber for cosmetics, and to use a hydrocarbon which is hardly soluble in water as a solvent. Compared to the synthetic method using a readily soluble solvent, the separation of inorganic salts and by-products as by-products and the recovery of the solvent are easier, and especially, since the solvent is not dissolved in the wastewater, the wastewater treatment is simplified and the industrial process is simplified. This is extremely advantageous for production.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07C 67/00 C07C 67/00 69/02 69/02 // C07B 61/00 300 C07B 61/00 300

Claims (6)

[Claims] 1. A method for producing a benzophenone represented by the following formula (2), which comprises reacting a polyhydroxybenzophenone represented by the following formula (1) with an alkyl halide in the presence of an alkali: (A), third
A method for producing a benzophenone represented by the following formula (2), wherein the method is carried out in a hydrocarbon solvent in the presence of a secondary amine and an alkali metal halide (B) or the above (A) and (B). Embedded image R: hydrogen, alkyl, alkoxy, halogen, carboxy, carboalkoxy or hydroxy. R ₁ and R ₂ may be the same or different and represent at least one selected from the group consisting of hydrogen, alkyl, alkoxy, halogen, carboxy, carboalkoxy and hydroxy. However, the case where both R ₁ and R ₂ are hydroxy is excluded. Embedded image R: the same as above R ₃ : alkyl R ₄ , R ₅ : at least one selected from the group consisting of hydrogen, alkyl, alkoxy, halogen, carboxy and carboalkoxy. 2. The hydrocarbon solvent is toluene, xylene,
The method for producing benzophenones according to claim 1, wherein the method is at least one selected from the group consisting of heptane and octane. 3. The process for producing benzophenones according to claim 1, wherein the hydrocarbon solvent is used in an amount of 0.7 to 3 times the amount of the polyhydroxybenzophenones of the formula (1). 4. The method for producing benzophenones according to claim 1, wherein the quaternary ammonium salt is represented by the following formula (3). Embedded image In the above formula, R ₆ , R ₇ , R ₈ and R ₉ are the same or different alkyl, or R ₆ is phenyl or benzyl, and R ₇ , R ₈ and R ₉ are the same or different. Is also a good alkyl. X is chlorine, bromine, iodine or hydroxy. 5. The method for producing benzophenones according to claim 1, wherein the tertiary amine is tributylamine or triethylamine. 6. The process for producing benzophenones according to claim 1, wherein the alkali metal halide is selected from the group consisting of potassium iodide, potassium bromide, sodium iodide and sodium bromide.