JPH0362704B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing polyhydroxybenzophenone. More particularly, the present invention relates to a method for producing polyhydroxybenzophenones with high yield and low coloration by subjecting hydroxybenzoates to Fries rearrangement. 2, 2′, 4,
4'-tetrahydroxybenzophenone, 2,2'-
Polyhydroxybenzophenones such as dihydroxy-4,4'-dimethoxybenzophenone are useful as ultraviolet absorbers. [Prior Art] Conventionally, as a method for producing polyhydroxybenzophenone, for example, as shown in U.S. Pat. No. 2,854,485 and U.S. Pat. Also known is a method of reacting in the presence of phosphorus oxychloride or phosphorus trioxide. Although the specification of this US patent states that polyhydroxybenzophenone can be produced in good yield, according to the experience of the present inventors, this method can produce polyhydroxybenzophenone in high yield and color. It is difficult to obtain polyhydroxybenzophenone with a small amount of phosphorus, and in addition, there are difficulties in treating wastewater containing phosphorus, and this has not been a satisfactory industrial method for producing polyhydroxybenzophenone. Furthermore, JP-A-57-154140 discloses a method of reacting aromatic carboxylic acid and phenol in the presence of alkanesulfonic acid, but in addition to the fact that the alkanesulfonic acid used is expensive, ,
In order to obtain polyhydroxybenzophenone in a relatively high yield, it is necessary to use 5 or more moles of alkanesulfonic acid per mole of aromatic carboxylic acid. The use of alkanesulfonic acid in equimolar amounts to aromatic carboxylic acid has the disadvantage that polyhydroxybenzophenone can only be obtained in a yield of about 20%. In addition, as another method for obtaining polyhydroxybenzophenone, US Pat. No. 2,694,729 describes
A method in which resorcinol dimethyl ether and phosgene are reacted in the presence of aluminum chloride using a chlorinated hydrocarbon as a solvent, followed by demethylation to obtain 2,2',4,4'-tetrahydroxybenzophenone. is disclosed. However, this method has a low yield of about 35 to 40%, making it unsuitable for industrial implementation. [Means for Solving the Problems] In view of the above circumstances, the present inventors have conducted intensive studies on the industrial production method of polyhydroxybenzophenone, and have found that I learned that polyhydroxybenzophenone can be obtained in high yield and with little coloring by Fries rearrangement.
We have now completed the present invention. That is, the present invention has the general formula (R represents an alkyl group, an alkoxy group, or a halogen atom, and R is 2 or more (n≧2 and/or q≧
In the case of 2), the substituents may be the same or different. m and p are integers of 1 to 5, n and q are integers of 0 or 1 to 4, m+n≦5 and p+
q≦5. ) is subjected to Fries rearrangement using at least one selected from zirconium halide, iron halide, zinc halide, tin halide, and bismuth halide as a catalyst. (R, m, n, p, q and m+n, p+q are the same as defined above.) This is a method for producing polyhydroxybenzophenone represented by: The present invention will be explained in detail below. The hydroxybenzoate used in the invention is
It can be obtained by reacting hydroxybenzene with phosgene without a catalyst or in the presence of a halogenated zirconium catalyst. The hydroxybenzene used in this reaction has the general formula (In the formula, R represents an alkyl group, an alkoxy group, or a halogen atom, and when R is 2 or more (j≧2), they may be the same substituent or different substituents. i
is an integer of 1 to 5, j is 0 or an integer of 1 to 4, i+
j≦5. ) is a compound represented by R is an alkyl group having 1 to 12 carbon atoms such as a methyl group, ethyl group, propyl group, butyl group, or octyl group, or an alkyl group having 1 to 12 carbon atoms such as a methoxy group, ethoxy group, propoxy group, butoxy group, or octoxy group. Examples include groups, halogen atoms such as fluorine, chlorine, bromine, and iodine. Further, when j represents an integer of 2 or more, R may be the same type of substituent or different types of substituents. Examples of the compound represented by the above general formula include catechol, resorcin, hydroquinone, 1,2,3-trihydroxybenzene, resorcin monomethyl ether, resorcin monooctyl ether, and 3,5-dihydroxytoluene. Both hydroxybenzene and phosgene can be purified to a high degree of purity, or they can be used as they are industrially produced. The method of the present invention can be carried out without a catalyst or with a zirconium halide as a catalyst. As the zirconium halide, chloride and/or bromide or a mixture thereof is preferably used. Hydroxybenzene and phosgene are generally reacted in the presence of a solvent. That is, in the case of no catalyst, hydroxybenzene is dissolved or suspended in a solvent, and in the case of using zirconium halide as a catalyst, hydroxybenzene and zirconium halide are dissolved or suspended in a solvent. A method is generally adopted in which the reaction is carried out by blowing phosgene under such conditions. As a solvent, carbon disulfide, nitrobenzene, 1,2-dichloroethane,
Chlorobenzene, bromobenzene, o-dichlorobenzene, m-dichlorobenzene, etc. can be used. When carrying out the reaction without a catalyst, the amounts of hydroxybenzene, solvent, and phosgene used are generally 3 to 40% by weight of hydroxybenzene in the solvent, and the amount of phosgene used is the theoretical amount relative to hydroxybenzene. The reaction temperature is generally about 50° to 150°C, preferably about 70° to 130°C. The concentration of hydroxybenzene in the solvent is approximately 40
When the concentration exceeds % by weight, the proportion of by-products produced increases, while when the concentration decreases, productivity deteriorates. or,
Even if a large amount of phosgene is used, commensurate effects cannot be obtained, so it is generally used in an amount of about 0.5 to 8 times the amount, preferably about 1 to 4 times the amount. Regarding the reaction temperature, if the temperature is above a suitable temperature range, the amount of by-products will increase significantly, while if it is below a suitable temperature range, it will take a long time to complete the reaction. When using zirconium halide as a catalyst, the amounts of hydroxybenzene, solvent, and phosgene to be used should be equivalent to those without a catalyst, and the amount of zirconium halide used as a catalyst should be about 0.05 to 1 mole of hydroxybenzene. It is added preferably in 2 moles, preferably about 0.1 to 1 mole, and the reaction temperature is generally about 0 to 90°C, preferably about 20° to 50°C. The amount of zirconium halide used is approximately 2
If the amount is more than twice the mole or above the suitable temperature range, the by-products will increase significantly and the production rate of hydroxybenzoate will be reduced. On the other hand, if the amount of zirconium halide is less than about 0.1 times the mole, or If the temperature falls below the preferred range,
It will take a long time for the reaction to complete. The time for blowing phosgene may be within a range that does not cause abnormal heat generation. After the introduction of phosgene, it is effective to provide a thermal formation period of about 1 to 20 hours to complete the reaction. Hydroxybenzoate produced by the reaction can be isolated by washing the reaction product with water to remove unreacted hydroxybenzene, then evaporating and recovering the solvent, and conducting concentration crystallization. Hydroxybenzoate with less coloring can be obtained by concentration crystallization, but if desired, further purification such as recrystallization can be carried out. Hydroxybenzoates obtained in this way include 3-hydroxyphenyl-2,4-dihydroxybenzoate, 2-hydroxyphenyl-3,4-dihydroxybenzoate, 4-hydroxyphenyl-2,4-dihydroxybenzoate, and 4-hydroxyphenyl-2,4-dihydroxybenzoate, depending on the hydroxybenzene used in the reaction. enyl-2,5-dihydroxybenzoate 2-hydroxyphenyl-2,4-dihydroxybenzoate 3-hydroxyphenyl-3,4-dihydroxybenzoate 4-hydroxyphenyl-2,4-dihydroxybenzoate 3-hydroxyphenyl- 2,5-dihydroxybenzoate 2-hydroxyphenyl-2,5-dihydroxybenzoate 4-hydroxyphenyl-3,4-dihydroxybenzoate 2,3-dihydroxyphenyl-2,3,4-
Trihydroxybenzoate (3-hydroxy-5-methyl)phenyl-
(2,4-dihydroxy-6-methyl)benzoate 3-methoxyphenyl-(2-hydroxy-4
-methoxy)benzoate and the like. Fries the hydroxybenzoate obtained as above in the presence of a specific catalyst.
A rearrangement reaction is carried out to produce polyhydroxybenzophenone. Examples of the catalyst include at least one selected from zirconium halides, iron halides, zinc halides, tin halides, and bismuth halides. Preferably, at least one selected from zirconium, zinc, tin chloride and/or bromide is used. It is also possible to add a protic acid such as hydrogen chloride together with the catalyst. By using these catalysts, the Fries rearrangement proceeds smoothly and the desired polyhydroxybenzophenone with little coloration can be obtained in high yield. As the hydroxybenzoate used in the Fries rearrangement reaction, the aforementioned reaction product solution of hydroxybenzene and phosgene can be used as is. Alternatively, hydroxybenzoate can be isolated from the reaction product solution and provided. In order to avoid the complexity of reaction operations, it is common industrially to use the reaction product liquid as it is. The amount of the Fries rearrangement catalyst used is about 0.1 to 4 times the mole of hydroxybenzoate present, preferably about 0.2 to 2 times the mole. If the amount of catalyst used exceeds about 4 times the mole, there will be a problem in terms of economic efficiency, and if it is less than about 0.1 times the mole, the rearrangement will not proceed sufficiently, which is not preferable. The reaction temperature is generally about 0 to 120°C, preferably about 30°C.
Performed at ~90°. If the reaction temperature is about 120° C. or higher, the produced polyhydroxybenzophenone will become highly colored, which is undesirable in terms of hue. Although there is no limit to the reaction time, generally reaction times of about 0.5 to 20 hours are employed. The polyhydroxybenzophenone produced by the reaction can be obtained by dropping cold water into the reaction product or by pouring the product into cold water, filtering the precipitated polyhydroxybenzophenone, washing with water,
The target polyhydroxybenzophenone with less coloring can be obtained by separating and purifying it by a usual separation and purification method such as recrystallization. The polyhydroxybenzophenones thus obtained include 3,3',4,4'-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, and Hydroxybenzophenone, 2,2',5,
5′-tetrahydroxybenzophenone, 2,2′,
3,3',4,4'-hexahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4,
4'-Dioctoxybenzophenone, 2,2',4,
4'-Tetrahydroxy 6,6'-dimethylbenzophenone, 2,3',4,4'-tetrahydroxybenzophenone, 2,2',4,5'-tetrahydroxybenzophenone, 2,3 ',4',5-tetrahydroxybenzophenone and the like. [Effects of the Invention] According to the method of the present invention detailed above, polyhydroxybenzophenone with little coloring can be produced from hydroxybenzoate at an extremely high yield of 90% or more. Hydroxybenzoate is obtained at a yield of about 70 to 80% from hydroxylbenzene, and the yield of polyhydroxybenzophenone based on hydroxylbenzene is about 60 to 80%. It is possible to produce polyhydroxybenzophenone with a higher yield and less coloring than the corresponding yield of about 35 to 40% in conventionally known methods, and its industrial value is extremely large. [Examples] The method of the present invention will be explained below using Examples, but the method of the present invention is not limited to these Examples. Example 1 24.6 g of 3-hydroxyphenyl-2,4-dihydroxybenzoate, 300 g of nitrobenzene,
12.0 g of zirconium chloride was placed in a 500 c.c. three-necked flask, replaced with _N2 , and then heated to 70°C. 70
The mixture was heat-treated at ℃ for 4 hours, and then aged for 4 hours.
After cooling, the reaction solution was analyzed by high-performance liquid chromatography, and it was found that 99% of the hydroxybenzoate had been converted, and the yield of 2,2',4,4'-tetrahydroxybenzophenone was 94% (based on hydroxybenzoate). It was generated with . Example 2 1 kg of nitrobenzene and 110 g of resorcinol
After purging the inside of the flask with N ₂ , the temperature was raised to 100°C, and 99 g of phosgene was blown in with stirring over 10 hours. As phosgene was blown in, the color of the reaction solution changed from light brown to blackish brown, and HCl gas was observed to be generated during the phosgene blowing. The reaction solution was once cooled to room temperature (as a result of analyzing the reaction solution with high performance liquid chromatography, it was found that
% yield of hydroxybenzoate) Next, zinc chloride was added to the reaction solution.
After charging 54.5g and raising the temperature to 70°C, heat treatment was performed at 70°C for 2 hours. After the heat treatment, the reaction product was cooled with water, 700 g of water was added dropwise, and the mixture was left stirring for 1 hour. The reaction product was filtered and washed with water to obtain 150 g of wet cake. The wet cake was dissolved in 2 kg of hot water, cooled and crystallized, and dried to obtain the desired 2,2',
4,4'-tetrahydroxybenzophenone 90.0g
was obtained (yield 73%, m.p 196-199°C) At this time, the conversion rate of resorcin was 86%, and the amount of unconverted hydroxybenzoate was 6% (based on resorcin). Example 3 1 kg of nitrobenzene and 110 g of resorcin were charged into a four-necked flask (No. 2). After purging the inside of the flask with N ₂ , the temperature was raised to 100°C. 99 g of phosgene was blown in with stirring over 10 hours, and then heated at 100°C for 4 hours. It was matured in After the reaction was completed, the reaction solution was cooled to room temperature, 68 g of zinc chloride was added, the temperature was raised to 70°C, and HCl
Heat treatment was performed at 70° C. for 4 hours while blowing gas at 8 g/H. After the heat treatment, the reaction product was cooled with water, 700 g of water was added dropwise, and after being left under stirring for 1 hour,
The reaction product was washed with water to obtain 162 g of wet cake. When the wet cake was dissolved in 2 kg of hot water, crystallized by cooling from the hot water and dried, 2,2',
4,4'-tetrahydroxybenzophenone 98.4g
was obtained (yield 80%). At this time, the conversion rate of resorcinol was 89%, and the amount of unconverted hydroxybenzoate was less than 1%. Examples 4 to 7, Comparative Examples 1 to 5 In Example 1, another metal chloride was used in place of the zinc chloride used in the second reaction (the metal chloride was used in a molar amount 0.5 times that of resorcinol), The reaction was carried out in the same manner as in Example 1.

【table】

[Table] Example 8 A reaction was carried out in the same manner as in Example 2 except that 3,5-dihydroxytoluene and iron chloride were used instead of resorcinol and zinc chloride. The amount of isolated 2,2',4,4'-tetrahydroxy-6,6'-dimethylbenzophenone (m.p 198°C) was 26 g, and the yield was 51%.

Claims (1)

[Claims] 1. General formula [R represents a lower alkyl group, m and p are 2-
3 is an integer, n and q are integers of 0 or 1. ] Hydroxybenzoate represented by zirconium halide, iron halide, zinc halide,
Fries using at least one selected from tin halide and bismuth halide as a catalyst
Dislocation, general formula (R, m, n, p, q are the same as defined above.) A method for producing polyhydroxybenzophenone represented by: 2 Polyhydroxybenzophenone is 2. The method for producing polyhydroxybenzophenone according to claim 1, wherein the polyhydroxybenzophenone is 2,2',4,4'-tetrahydroxybenzophenone represented by: