JPS5872530A - Preparation of alkyl-substituted dihydric phenol - Google Patents

Abstract

PURPOSE:To prepare the titled compound useful as an intermediate of pharmaceuticals, pesticides, etc., selectively, in high yield, by reacting a specific dihydric phenol with a lower alcohol in the presence of a long-life catalyst composed mainly of iron oxide, manganese oxide and chromium oxide. CONSTITUTION:An alkyl-substituted dihydric phenol is prepared by reacting a dihydric phenol having H atom bonded to the carbon atom adjacent to the OH- substituted carbon atom with a lower alcohol (e.g. methanol) in the presence of a catalyst composed mainly of iron oxide, manganese oxide and chromium oxide, at about 300-450 deg.C. The molar ratio of the lower alcohol to the dihydric phenol is about 2-7. The liquid space velocity of the supplied raw material vapor is about 0.5-5hr<-1>. The carbon atom adjacent to the OH-bonded carbon atom is selectively alkylated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyalkyl dihydric phenols selectively and in high yield from the reaction of dihydric phenols and lower alcohols.

Alkyl group-substituted dihydric phenols 1 In particular, alkyl group-substituted dihydric phenols having at least one alkyl group bonded to a carbon atom adjacent to a hydroxyl group-bonded carbon atom are used during the production of pharmaceuticals, agricultural chemicals, and resin formulations. It is useful for the body.

Conventional methods for producing alkyl group-substituted dihydric phenols include dihydric phenols and olefins in the presence of sulfuric acid, phosphoric acid, hydrogen fluoride, phosphoric acid/hydrogen fluoride, hydrochloric acid, or other acidic catalysts. Method of contacting in liquid phase [U.S. Patent No. 2]
, 051,473, U.S. Patent No. 2.544,8
No. 18 specification, U.S. Patent No. 2,831,817], contacting dihydric phenols and alcohol in a liquid phase in the presence of sulfuric acid, hydrogen fluoride, phosphoric acid, oxalic acid, or other acidic catalyst. How to do it (H, Meyeretal, Monats
h, 55/54.743 (1929), w, s.

0alcottSJ, Am, Chem, Soc, 6
1.1010 (1939)) have been proposed. The former method cannot produce polymethyl group-substituted dihydric phenols, which are the most useful among alkyl group-substituted dihydric phenols. In addition, it cannot be said that either method has high selectivity to alkyl group-substituted dihydric phenols and high yield thereof.

In addition, U.S. Patent No. 4,060,561 includes 4
- methoxyhydroquinone and methanol in the presence of a catalyst containing magnesium monoxide or magnesium oxide as a main component and further containing aluminum oxide, uranium oxide, titanium oxide, cerium oxide, manganese oxide, zinc oxide or iron oxide as a promoter component, A method has been proposed in which the reaction is carried out in the gas phase at a temperature of 550 to 550°C. but,
This method not only has low catalyst activity and low selectivity and yield to polyalkylhydroquinone and non, but also has the drawback that methanol is significantly lost due to decomposition during the reaction, and polymethylhydroquinone cannot be produced on an industrial scale. It is difficult to say that this is an excellent method for manufacturing.

The present inventors investigated a method for selectively producing alkyl-substituted dihydric phenols in high yield by improving the above-mentioned drawbacks of conventional methods. It has been discovered that the above object can be achieved by bringing specific dihydric phenols into contact with alcohol in the gas phase in the presence of a catalyst whose main component is at least one metal oxide selected from the group consisting of at least one metal oxide selected from the group consisting of: Reached.

Furthermore, according to the present invention, alkylation occurs selectively to the carbon atom adjacent to the hydroxyl group-bonded carbon atom, the catalyst has high activity, and alkyl group-substituted dihydric phenols can be selectively obtained in high yield. In addition, the loss of alcohol due to decomposition during the reaction is significantly lower than with conventional catalysts.
It is characterized by a small decrease in catalyst activity and a long catalyst life.

That is, the present invention uses a dihydric phenol (&) having at least one hydrogen atom bonded to a carbon atom adjacent to a hydroxyl group-bonded carbon atom and a lower alcohol (b),
Alkyl group substitution characterized by contacting in a gas phase in the presence of a catalyst (0) containing as a main component at least one metal oxide selected from the group consisting of iron oxide, manganese oxide, and chromium oxide. This is a method for producing dihydric phenols.

The dihydric phenols (a) used as raw materials in the method of the present invention are dihydric phenols having at least one hydrogen atom attached to a carbon atom adjacent to a hydroxyl group-bonded carbon atom, and are specifically is a dihydric phenol having at least one hydrogen atom bonded to a carbon atom adjacent to a hydroxyl group-bonded carbon atom, or a lower alkyl group-substituted product thereof.

Among these divalent phenyls (a), dihydric phenols having at least two or more hydrogen atoms bonded to the carbon atom adjacent to the hydroxyl group-bonded carbon atom or an alkyl group-substituted product thereof are preferable. Here, the lower alkyl group is usually an alkyl group having 1 to 3 carbon atoms, and specific examples thereof include methyl group, ethyl group, n-propyl group, and isopropyl group. Among these dihydric phenols having a lower alkyl group, dihydric phenols having a methyl group are preferably used. Specifically, the raw material dihydric phenols (a) include hydroquinones such as hydroquinone, methylhydroquinone, 2,5-dimethylhydroquinone, and 2,6-dimethylhydroquinone, or their lower alkyl groups; zorcin, 2- Methylresorcin-4-methylresorcin, 5-
Methylresorcin, 2,5-dimethylresorcin, 4,
Examples include resorcinols such as 5-dimethylresorcinol or their lower alkyl group-substituted products; catechol, 4-methylcatechol, 5-methylcatechol, 4,5-dimethylcatechol, and other catechols or their lower alkyl group-substituted products. can. The divalent phenols (a
), it is preferable to use hydroquinone, resorcinol catechol, or a methyl group-substituted product thereof, and it is particularly preferable to use hydroquinone or a methyl group-substituted product thereof.

Lower alcohol (1) used in the method of the present invention
) is usually an alcohol having 1 to 3 carbon atoms, specifically methyl alcohol, ethyl alcohol, n
-Propyl alcohol, isopropyl alcohol, etc. can be exemplified. Among these lower alcohols, methyl alcohol is preferably used. The proportion of the lower alcohol used is the same as that of the dihydric phenols (
Usually about 5 to about 10 moles, preferably about 1 to about 5 moles, particularly preferably about 2 moles per hydrogen atom bonded to the carbon atom adjacent to the phenolic hydroxyl group-bonded carbon atom in the molecule of &J. and about 5 moles.

The catalyst CO used in the method of the present invention is a catalyst containing as a main component at least one metal oxide selected from the group consisting of iron oxide, manganese oxide, and chromium oxide, and is made of only the metal oxide. It may be a catalyst consisting of the above metal oxide as a main component and containing a small amount of a co-catalyst component consisting of another metal or metal compound. Here, the material containing the metal oxide as a main component is usually 50% by weight or more of the metal oxide,
It is preferably a single-component catalyst or a multi-component catalyst containing 70% by weight or more, particularly preferably 90% by weight or more. Among catalysts containing these metal oxides as a main component, catalysts containing iron oxide, manganese oxide, or chromium oxide as a main component are preferred, and catalysts containing iron oxide as a main component are particularly preferred. .

The composition of these catalysts is usually 50% by weight or more, preferably 70% by weight of iron monooxide, manganese oxide or chromium oxide.
Above all, single-component catalysts or multi-component catalysts containing 90% by weight or more are particularly preferred. Co-catalyst components blended into the catalyst containing the metal oxide of the present invention as a main component include germalum, vanadium, silicon, gallium, niobium, molybdenum, indium, antimony,
Tellurium, hafnium, tantalum, tungsten, bismuth, aluminum, chromium, yttrium, cerium,
Metal compounds such as zinc, cobalt, magnesium, copper, boron, and tin, and oxides thereof are particularly preferred.

Next, the metal oxide catalyst will be specifically explained.

Catalysts containing iron oxide as a main component include: catalysts consisting of a single iron oxide component; binary catalysts containing iron oxide and a second catalyst component and containing iron oxide as a main component; A multi-component catalyst such as a ternary catalyst containing a second catalyst component and a third catalyst component and containing iron oxide as a main component can be mentioned. The second catalyst component includes gallium oxide, germanium oxide, yttrium oxide, niobium oxide, and hafnium oxide.
Examples include at least one metal oxide selected from the group consisting of tantalum oxide and bismuth oxide,
Among these, it is preferable to use at least one metal oxide selected from the group consisting of germanium oxide, gallium oxide, and hafnium oxide, as this provides a catalyst with excellent effects of the present invention, and germanium oxide is particularly preferred. It is preferable to use Examples of the third catalyst component include at least one selected from the group consisting of magnesium oxide, zinc oxide, aluminum oxide, silicon oxide, zirconium oxide, basic alkali metal compounds, and carbon; A ternary catalyst containing iron oxide as a main component and blended with the third catalyst component can suppress a decrease in catalyst activity, resulting in a long-life catalyst. Among these third catalyst components, at least one selected from the group consisting of magnesium oxide, aluminum oxide, silicon oxide, and basic alkali metal compounds is preferable. The mixing ratio of the second catalyst component is usually 0.003 metal atoms of the metal oxide of the second catalyst component per 1 gram atom of iron atom of iron oxide.
or about 0. - gram atom, preferably in the range of about 0.005 to about 0.15 gram atom. Further, when blending the third catalyst component, the blending ratio is usually 0.0001 to about 0.1 mol, preferably about 0.1 mole, as the third catalyst component per 1 gram atom of iron of iron oxide.
．． 001 to about 0.05 moles. Among the aforementioned catalysts containing iron oxide as a main component, when a multicomponent catalyst containing iron oxide as a main component is used, the reactivity is high and the ortho position selectivity of the alkylation reaction is high.
It is also preferable because decomposition of alcohol can be suppressed.

Catalysts containing manganese oxide as a main component include catalysts containing a single component of manganese oxide as described above; catalysts containing manganese oxide and a second catalyst component and containing manganese oxide as a main component; Examples include multi-component catalysts such as ternary catalysts containing manganese oxide, a second catalyst component, and a third catalyst component as a main component and containing manganese oxide as a main component. Examples of the second catalyst component include at least one metal compound selected from the group consisting of magnesium oxide, cerium oxide, zinc oxide, chromium oxide, iron oxide, and cobalt oxide. Further, as the third catalyst component, a basic alkali metal compound can be exemplified. The mixing ratio of the second catalyst component is usually 0,' as the metal atom of the metal oxide of the second catalyst component per gram atom of manganese oxide.
It ranges from O05 to about 0.5 gram atom. Also,
When blending the third catalyst component, the blending ratio is generally in the range of 0.0001 to about 0.05 mol of the metal compound as the third catalyst component per gram atom of manganese oxide.

Among the aforementioned catalysts containing manganese oxide as a main component, it is preferable to use a multicomponent catalyst containing manganese oxide as a main component.

Catalysts containing chromium oxide as a main component include catalysts consisting of a single component of chromium oxide as described above; binary catalysts containing chromium oxide as a main component and containing chromium oxide and a second catalyst component; A multi-component catalyst such as a ternary catalyst containing chromium oxide, a second catalyst component, and a third catalyst component and containing chromium oxide as a main component can be mentioned. The second catalyst component includes magnesium oxide, steel oxide, aluminum oxide,
Examples include at least one metal oxide selected from the group consisting of silicon oxide, boron oxide, tin oxide, germanium oxide, and iron oxide.

Further, as the third catalyst component, at least one compound selected from the group consisting of various sulfates and basic alkali metal compounds can be exemplified. The mixing ratio of the second catalyst component is generally in the range of 0.005 to about 0.5 gram atom of the metal oxide of the second catalyst component per gram atom of chromium atom of the chromium oxide. It is. Further, when the third catalyst component is blended, the blending ratio is usually in the range of 0.0001 to about 0.05 mol as the compound of the third catalyst component per 1 gram atom of chromium atom of chromium oxide. It is. Among the catalysts containing chromium oxide as a main component, it is preferable to use a multicomponent catalyst containing chromium oxide as a main component.

In the method of the present invention, the metal oxide catalyst containing the transition metal oxide as a main component is usually used as a fixed bed catalyst by filling it in a reaction tube or a packed tower. At this time, these catalysts are packed in an appropriate shape, such as powder, granules, spheres, tablets, or lumps. The length of the reaction tube or packed column filled with the fixed bed catalyst and the cross-sectional area perpendicular to the flowing gas are appropriately determined by the liquid hourly space velocity of the feed gas mixture and the linear velocity of the feed gas mixture.

In the method of the present invention, the reaction between the dihydric phenol (L) and the lower alcohol (b) is carried out using the catalyst.
It is carried out in the presence of C) in the gas phase by contacting with heating. At that time, a method may be adopted in which only a gas mixture consisting of the dihydric phenols and the lower alcohol is brought into contact with the catalyst; It is also possible to employ a method in which a gas mixture is brought into contact with a catalyst. As a diluent gas inert to the reaction, nitrogen,
Helium, argon, carbon dioxide, certain steam, benzene, toluene, xylene, n-hexane, n-hebutane, n-
Examples include decane.

In carrying out the method of the present invention, the gaseous mixture containing the raw materials and the catalyst may be brought into contact with each other in the gas phase by a fixed bed method, a moving bed method, or a fluidized bed method. However, it is preferable to employ a contact method using one fixed bed method as a production method on an industrial scale.

In the method of the present invention, the reaction is carried out under heating.
The temperature during the reaction is generally in the range of about 250 to about 500,000°C, preferably about 600 to about 450°C, and particularly preferably about 300 to about 400°C. In addition, the liquid hourly space velocity (LH3V) during the reaction is usually about 0.01 to about 50 hr1, preferably about 0.05 to about 10 hr1.
r, particularly preferably from about 0.1 to about 1. Ohr
is within the range of

The pressure during the reaction is usually reduced pressure or about 20 kg/cm.
2-G, preferably about 0 to about 10 kg/am2-
G, particularly preferably about 0 to about 5 kg/cm G
is within the range of

In the method of the present invention, a reaction mixture can be obtained by condensing the vapor of the gas/thermal mixture flowing out of the reactor, and a reaction product mixture can be obtained by removing the diluent from the reaction mixture.

Unreacted lower alcohols and unreacted dihydric phenols can be recovered from this reaction product mixture by means such as distillation, and these can be recycled and reused in the reaction system. ``The crude lower alkylated product obtained as a high boiler is separated into products such as mono-lower alkylated products and tri-lower alkylated products by conventional means such as rectification, extraction, and adsorption. Intermediates such as mono-lower alkylated products and/or di-lower alkylated products are supplied to the reaction system together with dihydric phenols (&) as raw materials as necessary to produce the desired polyalkylated product. It can also be reused for circular purposes.

According to method 1 of the present invention, it is possible to selectively lower alkylate the wood carbon atom adjacent to the hydrocarbon-bonded carbon of the dihydric phenol as a raw material. Decomposition reactions can be suppressed. Moreover, there is an advantage that the activity of the catalyst does not decrease during the reaction and the life of the catalyst is long.Next, the method of the present invention will be specifically explained with reference to Examples.

Example 1 525g of ferric nitrate nonahydrate for 101! was dissolved in distilled water, and an approximately 5% aqueous alemonia solution was added to adjust the pH of the island stream to 8. The formed precipitate was washed with water and filtered.

The cake thus obtained was dried at 90°C for a day and night, and then baked at 450°C for 3 hours to prepare iron oxide.

After filling a Pyrex reaction tube with an inner diameter of 20 mmφ with 20 ml of catalyst crushed into 20 to 42 meshes,
It was heated to 370°C. After reaching a predetermined temperature, a mixture of resorcinol/methanol with a molar ratio of 175 was added at 15 ml/h.
◇The results are shown in Table 1.

Example 2 After dissolving 202.0 g of ferric nitrate nonahydrate in 21 distilled water, 25% ammonia water was gradually added to reduce the pH of the liquid.
H was set to 7. The formed precipitate was washed with water and filtered.

1.65 g of germanium dioxide was added to this and kneaded for 1 hour using an automatic mortar. This was dried at 90'C for a day and night, and then calcined at 450°C for 6 hours to prepare a catalyst consisting of iron oxide and germanium oxide.

When the catalyst prepared in this way was analyzed by atomic absorption method,
It was confirmed that the iron/germanium atomic ratio was 9nia/3.

Using this catalyst, a methylation reaction of resorcinol was carried out in the same manner as in the example. The results are shown in Table 1.

Example 6 450 g of manganese nitrate hexahydrate was dissolved in 51.7 distilled water. Approximately 5% ammonia aqueous solution was added. The pH of the solution was adjusted to 7.
0 and continued stirring for about 3 hours. The obtained precipitate was washed, filtered, and then dried at 90°C for one day and night. This was further fired at 600°C in air. The manganese oxide obtained in this way is used as a catalyst.

The reaction was carried out in the same manner as in Example 1, except that the reaction temperature was changed to 400°C. The results are shown in Table 1.

Comparative Example 1 The methylation reaction of resorcin was carried out in the same manner as in Example 1, except that alumina N611 manufactured by 8Ki Kagaku Co., Ltd. was used as a catalyst, and the results were shown in Table 1. After adding 5 wt% of neutral silica sol to the aqueous solution of the compound, approximately 5% ammonia aqueous solution was added until the pH of the solution
A catalyst consisting of iron oxide and silicon oxide was prepared in the same manner as in Example 1 except that the resulting precipitate was cured. When the catalyst thus prepared was analyzed by atomic absorption spectroscopy, it was confirmed that the atomic ratio of iron/germanium was 93/7.

This catalyst was crushed into 42 to 20 meshes and 120m/
After filling a Pyrex reaction tube with an inner diameter of 23 mm,
Heated to 400°C. After reaching a predetermined temperature, add 15 ml of a mixed solution with a molar ratio of hydroquinone/methanol/water of 1/10/2! The reaction was carried out by supplying at a rate of /hr.
The results are shown in Table 2.・Comparative Example 2 After compressing Kyowa Kagaku Co., Ltd. magnesium oxide powder into tablets, 42
The methylation reaction of hydroquinone was carried out in the same manner as in Example 4, except that a catalyst pulverized into 20 to 20 meshes was used. The results are shown in reward 2.

/ Example 5 A methylation reaction of catechol was carried out using the catalyst made of iron oxide and germanium oxide used in Example 2. 11
), the molar ratio of catechol/methanol/water is 115.
Example 1 was carried out in the same manner as in Example 1, except that a composition of /2 was used and the reaction temperature was 390°C. The results are shown in Table 3.

Table 6゜Catalyst Iron oxide/germanium oxide (Fe/Ge, 97
15) Reaction temperature: 390°C Example 6 Catechol was isopropylated in the same manner as in Example 5, except that raw materials having a molar ratio of catechol/isopropyl alcohol/water of 1/10/2 were used. The results are shown in Table 4.

Table 4゜Catalyst Iron oxide/germanium oxide (Fe/Ge, 97
/3) Reaction temperature 390°C

Claims (7)

[Claims] (1) A dihydric phenol (&) having at least one hydrogen atom bonded to a carbon atom adjacent to a hydroxyl group-bonded carbon atom and a lower alcohol ~) selected from the group consisting of iron monooxide, manganese monooxide, and chromium oxide. A method for producing alkyl group-substituted dihydric phenols, which comprises contacting them in a gas phase in the presence of a catalyst R(c) containing at least one selected metal oxide as a main component. (2) The method according to claim (1), wherein the Jt-valent phenol (a) is a dihydric phenol or a methyl group-substituted product. (2) The method according to claim (1), wherein the lower alcohol is methanol. (3) The method according to claim 0, wherein the reaction temperature is maintained in the range of about 300 to about 450°C. 4. The method of claim 1, wherein the molar ratio of lower alcohol to dihydric phenols in the feed gas is maintained in the range of about 2 to about 7. 5. The method of claim 1, wherein the liquid hourly space velocity of the feed gas is maintained in the range of about 0.5 to about 5 hr-1. (6) The catalyst is a catalyst containing iron oxide, manganese oxide, or chromium oxide as a main component.
The method described in item 0. (7) The method according to claim (1), wherein the catalyst is a multicomponent catalyst containing iron oxide as a main component.