JPH0342256B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing polyhydroxybenzophenone. More specifically, the present invention relates to a method for producing polyhydroxybenzophenone with high yield and little coloring by reacting hydroxybenzene and phosgene in the presence of a halogenated zirconium catalyst.
Polyhydroxybenzophenones such as 2,2',4,4'-tetrahydroxybenzophenone and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone are useful as ultraviolet absorbers. It is. [Prior Art] Conventionally, methods for producing polyhydroxybenzophenone include, for example, US Pat. No. 2,854,485;
As shown in the specification of the same No. 2921962, a method is known in which an aromatic carboxylic acid and a phenol are reacted in the presence of zinc chloride, phosphoric acid, and phosphorus oxychloride or phosphorus trichloride. 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 without coloring. It is difficult to obtain a small amount of polyhydroxybenzophenone, and in addition, there are difficulties in treating wastewater containing phosphorus, and this method has not been satisfactory as an 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. When using an equimolar amount of alkanesulfonic acid with respect to aromatic carboxylic acid, polyhydroxybenzophenone has the disadvantage that a yield of only about 20% can be obtained. In addition, as another method for obtaining polyhydroxybenzophenone, US Pat. No. 2,694,729 describes
A method of reacting resorcinol dimethyl ether and phosgene 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. The present inventors have discovered that polyhydroxybenzophenone can be obtained in high yield and with little coloration by reacting in the presence of polyhydroxybenzophenone, leading to the completion of the present invention. That is, the present invention is based on the general 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 or different substituents. i is an integer of 1 to 5, j is 0 or an integer of 1 to 4, and i+j≦5. ] One or more hydroxybenzenes represented by the following are reacted with phosgene in the presence of a halogenated zirconium catalyst. [R represents an alkyl group, an alkoxy group, or a halogen atom, and R is 2 or more (n≧2 and or q≧2)
In the case of , the substituents may be the same or different. m and p are integers of 1 to 5, n and q are 0 or 1
It is an integer of ~4, m+n≦5 and p+q≦5. ] This is a method for producing polyhydroxybenzophenone represented by: The present invention will be explained in detail below. Hydroxybenzene used in the present invention 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]. R is an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group,
Examples thereof include alkoxy groups having 1 to 12 carbon atoms such as methoxy group, ethoxy group, propoxy group, butoxy group, and octoxy group, and 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, resorcinol, hydroquinone, 1,2,3-
Trihydroxybenzene, resorcin monomethyl ether, resorcin monooctele ether,
Examples include 3,5-dihydroxytoluene. The reaction product of the present invention has the general formula (R, m, p, q and m+n, p+q are the same as the above-mentioned formula.) It is a polyhydroxybenzophenone represented by the following and is a compound corresponding to the above-mentioned hydroxybenzene used as a raw material. Such polyhydroxybenzophenones include 3,3',4,4'-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2',5, 5'-tetrahydroxybenzophenone, 2,2',3,3',4,4'-hexahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone,
2,2'-dihydroxy-4,4'-dioctoxybenzophenone, 2,3',4,4'-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone , 2,3',4,5'-tetrahydroxybenzophenone and the like. Hydroxybenzene and phosgene are generally reacted in the presence of a solvent. A method is adopted in which hydroxybenzene and zirconium halide are dissolved or suspended in a solvent, and phosgene is blown into the solution to react. Alternatively, hydroxybenzene, zirconium halide, and phosgene can be dissolved or suspended in a solvent at a low temperature of about 0 to 10°C in advance, and the reaction can be carried out while raising the temperature. As a solvent, carbon disulfide, nitrobenzene,
1,2-dichloroethane, chlorobenzene, bromobenzene, O-dichlorobenzene, m-dichlorobenzene, etc. can be used. Among them,
Nitrobenzene is highly polar and is preferred as a solvent because it easily dissolves hydroxybenzene and zirconium halide. The amounts of hydroxybenzene, solvent, zirconium halide, and phosgene to be used vary depending on the type of target product, reaction method, etc., and cannot be unconditionally defined, but in general, hydroxybenzene is added to the solvent at a ratio of about 3 to 40% by weight. , the amount of phosgene used is approximately the theoretical amount for hydroxybenzene.
0.5 to 8 times the mole, preferably about 1 to 4 times the mole,
Zirconium halide with hydroxybenzene 1
About 0.1 to 4 times the mole, preferably about 0.2
~2 times the mole amount is added. When the concentration of hydroxybenzene in the solvent exceeds about 40% by weight, the proportion of by-products produced increases, while when the concentration decreases,
Since productivity deteriorates, the reaction is generally carried out at about 3 to 40% by weight, preferably about 7 to 20% by weight. Further, even if a large amount of phosgene is used, a commensurate effect cannot be obtained, so it is generally used in about 0.5 to 8 times the molar amount, preferably about 1 to 4 times the molar amount. When the amount of zirconium halide used exceeds about 4 times the mole, the amount of by-products increases significantly, while when it is less than about 0.1 times the mole, the reaction does not proceed sufficiently, which is not preferable. The reaction temperature is about 0 to 120°C, preferably about 30 to 90°C.
Conducted at °C. If the temperature exceeds the suitable range,
The increase in by-products becomes significant, and on the other hand, below the preferred temperature range, it takes a long time to complete the reaction. The time for blowing or dropping phosgene may be within a range that does not cause abnormal heat generation due to blowing or dropping. After the introduction of phosgene, it is effective to provide an aging time of about 1 to 20 hours to complete the reaction. Hydroxybenzoate, which is considered to be an intermediate, can also be obtained depending on reaction conditions such as reaction temperature, reaction time, and catalyst amount. The polyhydroxybenzophenone produced by the reaction can be prepared by dropping cold water into the reaction product or by pouring the product into cold water and filtering, washing with water, recrystallizing the precipitated polyhydroxybenzophenone, etc. The target polyhydroxybenzophenone with less coloring can be obtained by separating and producing it by a conventional separation and purification method. [Effect of the invention] According to the method of the present invention detailed above, 2, 2', 4,
In the case of 4'-tetrahydroxybenzophenone, the yield was about 60% compared to the 35-40% yield of the conventionally known method.
It is possible to produce polyhydroxybenzophenone with extremely high yield of ~80% and less coloring.
Its industrial value is extremely large. [Example] The method of the present invention will be explained below using Examples.
The method of the invention is not limited to these examples. Example 1 1 kg of nitrobenzene, 110 g of resorcinol, and 58 g of zirconium chloride were placed in a 24-necked flask, and the inside of the flask was purged with N ₂ gas, and then the temperature was raised to 70°C.
Next, 99g of phosgene was added to the temperature at 70°C over 5 hours.
The mixture was aged for 4 hours after bubbling while stirring. After aging, the reaction product is cooled with water and 500 ml of water is added.
g dropwise, and after standing for 1 hour under stirring, filter the product.
After washing with water, 152 g of a yellow wet cake was obtained. When the wet cake was dissolved in hot water, cooled, recrystallized, and dried, 2,2',4,4'-
91 g of tetrahydroxybenzophenone were obtained. The conversion rate of resorcinol was 85%, and 2,2′,
The yield of 4,4'-tetrahydroxybenzophenone was 74%. Zirconium bromide instead of zirconium chloride
The reaction was carried out in the same manner as above except that 100 g was used.
As a result, the yield of 2,2',4,4'-tetrahydroxybenzophenone with little coloring was 71%. Comparative Examples 1 to 8 The reaction was carried out in the same manner as in Example 1, except that the zirconium halide was changed to the metal chloride shown in Table 1. The amount of metal chloride is per mole of resorcinol.
It was prepared at a ratio of 0.5 mol. The results are shown in Table 1.

[Table] Zophenone Example 2 600 g of nitrobenzene, 45 g of resorcinol monomethyl ether, and 42 g of zirconium chloride were placed in the four-necked flask in step 1, and after purging the inside of the flask with N ₂ gas, the temperature was raised to 70°C. Then phosgene
36g was poured into the solution over 2 hours with stirring while maintaining the temperature at 70°C, and then aged for 4 hours. After water cooling approx.
200 g of water was added dropwise, and the mixture was left stirring for 1 hour. Add 15% NaOH aqueous solution to the separated nitrobenzene layer.
200 g was added, and the reaction product was extracted and neutralized with 15% HCl to precipitate the product. When the precipitate was washed with water and dried, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (m.
137-138°) was obtained. The yield was 56%.

Claims (1)

[Claims] 1. General formula [R represents an alkoxy group, i is an integer of 1 to 2, and j is an integer of 0 or 1. ] One or more hydroxybenzenes represented by the formula are reacted with phosgene in the presence of a zirconium halide catalyst to form a compound of the general formula [R represents an alkoxy group, m and p are 1-2
, n and q are integers of 0 or 1. ] A method for producing polyhydroxybenzophenone represented by: 2 Polyhydroxybenzophenone is The method for producing polyhydroxybenzophenone according to claim 1, wherein the polyhydroxybenzophenone is 2,2',4,4'-tetrahydroxybenzophenone represented by: