JPS643174B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for selectively ortho-substituting a phenol that is unsubstituted at least one ortho position with an aldehyde or a ketone. It has not been known to directly perform selective orthoalkylation of phenols using aldehydes or ketones. BACKGROUND ART Condensation reactions of aldehydes and ketones with phenols in the presence of catalysts have been carried out for a long time to produce polymers and diphenylmethane-type compounds. Furthermore, it is known that alkylphenols can be obtained by thermally decomposing these compounds, but only para-alkyl substituted products can be obtained in low yields. The present invention provides a method for selectively substituting phenols at the ortho position using aldehydes such as benzaldehyde, acetophenone, and acetone, and ketones. In the presence of a catalyst, a phenol having at least one unsubstituted ortho position is converted into a phenol having the following general formula: (However, R ¹ is hydrogen, an alkyl group or an aryl group, and R ² is an alkyl group or an aryl group.) general formula for (wherein R ¹ and R ² are the same as above, and R ³ to R ⁶ are hydrogen, halogen, or hydrocarbon groups). The phenols used as raw materials in the method of the present invention are those having at least one ortho-position hydrogen, and have the following general formula: (However, R ³ to R ⁶ are hydrogen, halogen, or a hydrocarbon group.) Here, halogens include fluorine, chlorine, bromine, and iodine, and examples of hydrocarbon groups include alkyl groups, aryl groups, and aralkyl groups. Specifically, these compounds include phenols; cresols such as o-cresol, m-cresol, and p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, and 3,5-xylenol; xylenol, 2,3,4-trimethylphenol, 2,3,5-trimethylphenol, trimethylphenol such as 3,4,5-trimethylphenol, and orthohydrogen such as 2,3,4,5-tetramethylphenol. methyl group-substituted phenols; halogen-substituted phenols in which at least one methyl group of these methyl group-substituted phenols is substituted with a halogen such as chlorine or bromine; group, propyl group,
Examples include hydrocarbon group-substituted phenols substituted with a hydrocarbon group such as a butyl group, a cyclohexyl group, and a phenyl group. Among these phenols having hydrogen at the ortho position, it is preferable to apply the method of the present invention to phenol, o-cresol, or a mixture thereof. Further, the aldehyde or ketone used in the present invention is a compound represented by the above-mentioned general formula (), and the alkyl group in the general formula may be a substituted or unsubstituted alkyl group, for example, a carbon number of 1 to 1.
6 alkyl groups, such as methyl, ethyl, n
-propyl group, iso-propyl group, n-butyl group,
Examples include iso-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, etc. Aryl groups include substituted or unsubstituted aryl groups, such as phenyl group, tolyl group, xylyl group, chlorophenyl group, Examples include bromophenyl group. More specific examples of these compounds include aldehydes such as acetaldehyde, propylaldehyde, butyraldehyde, isobutyraldehyde, and benzaldehyde, and ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, and phenyl methyl ketone. can. The proportion of these aldehydes and ketones to be used is generally about 0.1 to about 10 moles, particularly preferably about 1 to about 5 moles, per mole of the other raw material phenol. Further, hydrogen may generally be present in an equimolar amount corresponding to the reaction amount of aldehyde or ketone. In practice, from about 0.1 to about 10 mol, particularly preferably about 0.5 mol, per mol of aldehyde or ketone fed.
It is desirable to supply hydrogen in the range of 2 to 2 moles as hydrogen gas. The pressure of hydrogen gas is usually about 0 kg/cm ² -G to about 10 kg/cm ² -G. The presence of water in the reaction system does not adversely affect the reaction.
In order to prevent a local temperature rise in the catalyst layer, water may be supplied as needed for about 0.1 mol to about 10 mol, particularly preferably about 0.5 to about 2 mol, of water per 1 mol of aldehyde or ketone supplied. It will be done. The catalyst used in the present invention is a catalyst containing iron oxide as a main component; more specifically, a binary catalyst containing iron oxide and a second catalyst component and containing iron oxide as a main component; Examples include multi-component catalysts such as ternary catalysts containing iron, a second catalyst component, and a third catalyst component and containing iron oxide as a main component. Examples of the second catalyst component include germanium oxide, zirconium oxide, and bismuth oxide, and among these, it is particularly preferable to use germanium oxide. The third catalyst component may include chromium oxide,
A ternary catalyst containing iron oxide as a main component, which is blended with these third catalyst constituents, can suppress a decrease in catalyst activity, resulting in a long-life catalyst. The mixing ratio of the second catalyst component is usually about 0.003 to about 0.3 gram atom, preferably about 0.005 to about 0.3 gram atom, as metal atom of the metal oxide of the second catalyst component per gram atom of iron atom of iron oxide. It is in the range of 0.15 gram atom. Further, when blending the third catalyst component, the blending ratio is usually about 0.0001 to about 0.1 mole, preferably about 0.001 to about 0.05 mole, as the third catalyst component per gram atom of iron of iron oxide. range. Among the above-mentioned catalysts containing iron oxide as a main component, the multicomponent catalyst containing iron oxide as a main component has high reactivity, high ortho-position selectivity, and is effective in decomposing aldehydes and ketones. This is preferable because it can be suppressed. The method for preparing the catalyst used in the method of the present invention includes the iron oxide (a) prepared by the above method, the second component (b) made of the metal oxide, the third component (c) and, if necessary, Method of blending other catalyst components: an iron compound that can become iron oxide (a) by calcination, a metal compound that can become the second component (b) made of the metal oxide by calcination, and calcination. A method of firing a mixture consisting of the metal compound or carbon that can become the third component (c) and other catalyst components as necessary, or a method of firing after drying an aqueous solution of the mixture. I can give an example. In the method of the present invention, as a method for preparing a catalyst when using a catalyst in which the iron oxide (a), the second component (b) made of the metal oxide, and the third component (c) are supported on a carrier. is an iron compound that can become iron oxide by firing, the metal compound that can become the second component (b) made of the metal oxide by firing, and the third component (c) that can also be fired by firing. Examples include a method in which the carrier is impregnated with an aqueous solution of a mixture of the metal compound or carbon that can be used as the catalyst, and other catalyst components if necessary, and then fired. The reaction of the present invention is usually carried out in the gas phase, but can also be carried out in the liquid phase. When the reaction is carried out in the gas phase,
The reaction temperature is usually 250 to 450°C, preferably 300°C.
to 400℃. During the reaction, the catalyst can be used as a fixed bed catalyst or as a fluidized bed catalyst. Liquid hourly space velocity (LHSV) of the feedstock when the reaction is carried out in fixed bed mode.
is usually 0.1 to 10hr ^-1 , preferably 0.2 to 10hr -1
It is in the range of 5hr ^-1 . In addition, the reaction can usually be carried out under reduced pressure or increased pressure, but preferably 1 to 30 kg/cm ²
-G. After separating unreacted aldehyde or ketone from the reaction mixture, ortho-substituted phenols can be obtained by treatment according to conventional methods such as distillation, crystallization, and extraction. It is desirable that the recovered unreacted aldehyde or ketone and phenols be recycled and reused in the reaction. According to the reaction of the present invention, the ortho-position hydrogen of phenols is replaced with an alkyl group or an aralkyl group, and the following general formula (wherein R ¹ is hydrogen, an alkyl group or an aryl group, R ² is an alkyl group or an aryl group, and R ³ to R ⁶ are hydrogen, halogen or a hydrocarbon group) Phenols or orthoaralkyl group-substituted phenols can be obtained in good yield and with good selectivity. Next, the method of the present invention will be specifically explained using examples. The meaning of each term used below and the calculation method are as follows. Phenol conversion rate (%) = phenol amount supplied (mol)
−Amount of unreacted phenol (mol)/Amount of phenol supplied (mol)
) × 100 Selectivity of each product component (%) = Production amount of each component (mol
) / Amount of phenol supplied (mol) - Amount of unreacted phenol (m
ol) × 100 Example 1 After dissolving 202.0 g of ferric nitrate nonahydrate and 4.87 g of zirconium tetrachloride in the distilled water of 2, 25%
Aqueous ammonia was gradually added to adjust the pH of the solution to 7.
The generated precipitate was washed with water, dried at 90°C for a day and night, and then calcined at 450°C for 3 hours to prepare a catalyst consisting of iron oxide and zirconium oxide. When the catalyst thus prepared was analyzed by atomic absorption spectroscopy, it was confirmed that the atomic ratio of iron:zirconium was 97:3. 20ml of catalyst crushed into 6-10 meshes with inner diameter of 20mm
After filling a Pyrex reaction tube, the mixture was heated to 355°C. After reaching the specified temperature, add a mixture of acetone/phenol with a molar ratio of 5 to 14 ml/hr.
(LHSV0.7hr ^-1 ), and the reaction was carried out while hydrogen gas was flowing at a rate of 100ml/min at normal pressure. The reaction products were analyzed by gas chromatography. The results are shown in Table 1.

[Table] Example 2 Metacresol and acetone were reacted in the same manner as in Example 1 except that the raw material phenol was changed to metacresol. The results are shown in Table 2.

【table】

[Table] Example 3 After dissolving 202.0 g of ferric nitrate nonahydrate in distilled water from step 2, 25% ammonia water was gradually added,
The pH of the liquid was set to 7. The generated precipitate was washed with water. 2.16 g of germanium dioxide and 2.47 g of chromium nitrate nonahydrate were added to this and kneaded for 1 hour using an automatic mortar. This was dried at 90℃ for a day and night, and then
By firing at 450°C for 3 hours, a ternary catalyst consisting of iron oxide, germanium oxide, and chromium oxide was prepared.
The catalyst prepared in this way was analyzed by atomic absorption method,
The atomic ratio of iron: germanium: chromium is 95:4.0:
Confirmed that it is 1.0. 20ml of catalyst crushed into 6-10 meshes with inner diameter of 20mm
After filling a Pyrex reaction tube, the temperature was set at 360°C, and a mixture of phenol:acetophenone:H ₂ O in a molar ratio of 1:10:2 was heated at LHSV 0.3hr ^-1 .
Hydrogen gas was supplied at 75 ml/min at the same time. The reaction results are shown in Table 3.

[Table] Example 4 Fe ₂ O ₃ -GeO ₂ - prepared by the method of Example 3
Filled with _Cr2O3 , a mixed solution of phenol:benzaldehyde with a molar ratio _of 1:3 was heated at 355℃.
The catalyst bed was passed through the catalyst bed with 75 ml/min of H ₂ gas at a feed rate of LHSV 0.5 hr ^-1 . The results are shown in Table 4.

[Table] Example 5 A catalyst was prepared in the same manner as in Example 1 except that zirconium tetrachloride was replaced with bismuth nitrate pentahydrate 7.50%. Using this catalyst, 2,4-xylenol and isobutyraldehyde (mixing ratio 1:5 molar ratio) were reacted in the same manner as in Example 4. The results are shown in Table 5.

【table】

Claims (1)

[Scope of Claims] 1. A catalyst comprising iron oxide and a second component (wherein the second component is germanium oxide, zirconium oxide or bismuth oxide), or a catalyst comprising iron oxide, the second component and chromium oxide. In the presence of a catalyst, a phenol having at least one unsubstituted ortho position and the general formula (In the formula, R ¹ is hydrogen, an alkyl group or an aryl group, and R ² is an alkyl group or an aryl group.) general formula for A method for producing ortho-alkyl-substituted phenols or ortho-aralkyl-substituted phenols represented by the formula (wherein R ¹ and R ² are the same as above, and R ³ to R ⁶ are hydrogen, halogen, or hydrocarbon groups).