JPS59137432A - Production of alkylphenol - Google Patents

Abstract

PURPOSE:To produce the titled compound under mild condition, in high yield, by reacting a phenol with an aldehyde catalytically in the presence of H2 using a catalyst composed of a compound having sulfonic acid group and/or an oxy acid of sulfur in combination with a VIII-group metal. CONSTITUTION:An alkylphenol is produced by reacting a phenolic compound catalytically with an aldehyde in the presence of hydrogen preferably under pressure of 3-50atm at 80-150 deg.C, using a catalyst composed of (A) one or more acids selected from the compounds having sulfonic acid group (e.g. p-toluenesulfonic acid, m-sulfonic acid, etc.) and the oxy acids of sulfur (e.g. sulfuric acid, sulfurous acid, etc.) and (B) a VIII-group metal (e.g. Pd, Pt, etc.). The reaction is preferably carried out in the presence of a reaction solvent comprising an organic carboxylic acid having a pKa of >=4 (at 25 deg.C) or a compound giving said organic carboxylic acid by hydrolysis (e.g. gamma-butyrolactone).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for alkylating phenols.

According to the method of the present invention, alkylphenols can be produced in good yield and at low production cost under mild conditions.

Reactions in which nuclear alkylation, such as nuclear methylation, selectively occurs at the ortho and ortho positions of phenols such as phenol or substituted phenols, are useful in the synthesis of stabilizers, additives, intermediates for organic drugs, and the like. For example, 2,6-
Sheet-tert-butyl p-cresol is generally p-
Although it is synthesized from cresol, p-cresol is usually obtained in the form of a mixture with m-cresol, so pure p-cresol is separated from these mixtures, or the mixture is tert-butylated. After, p-
It is necessary to separate the tert-butylated derivative of cresol. Therefore, separation costs are high, and the consumer of the by-produced m-cresol or tert-butylated derivative of m-cresol becomes a problem, and the balance between demand and demand for both products is disadvantageously high. If phenol is used as a starting material, there is no such concern; for example, phenol can be converted into 2,6-
If the method of tert-butylation followed by 4-methylation can be performed with good yield, it can be replaced with the above method. A method of using methanol as a nuclear methylating agent for phenol is known, but the reaction usually needs to be carried out at a fairly high temperature, and the reaction has a group that is easily removed thermally, such as a tert-butyl group or an alkoxy group. Not suitable for nuclear methylation of phenols.

On the other hand, in order to obtain alkylphenols, a method using aldehydes as an alkylating agent is also known. For example, it is disclosed in U.S. Pat. No. 2,401,608, U.S. Pat. However, these methods use basic catalysts and have problems such as many side reactions, insufficient yield of the target product, and long and complicated steps, so they are still not satisfactory methods. Ta.

A method using an acidic catalyst, which is an improvement over the above method using a basic catalyst, is disclosed in JP-A-52-153920. This invention proposes the use of an acid with an appropriate strength as a catalyst, and the acid strength ranges from 0 to 0 in terms of pKa.
1 to 5.01, preferably 1.0 to 4.0, one or more organic acids or inorganic acids are used. Specific examples include lower fatty acids such as acetic acid and propionic acid, lower fatty acids such as monochloroacetic acid and dichloroacetic acid, oxalic acid, and
It praises organic acids such as phosphoric acid and benzoic acid, and inorganic acids such as hydrochloric acid and phosphoric acid. If an acid with a weak acid strength is used, the reaction rate will be slow, and if an acid with too strong an acid strength is used, a large amount of methylene crosslinking products of raw material phenols will be produced as by-products, so it is recommended to use an acid with an appropriate acid strength. Preferably, for example, 1.
When only lower fatty acids are used as acids, the reaction selectivity is good, but the reaction rate is slow.On the other hand, when only acids with strong acid strength such as lower fatty acids are used, the reaction rate is slow. Although it is fast, it has the disadvantage of slightly poor selectivity, so it is stated that the most preferred method is to use a mixture of I4 lower fatty acids and organic acids with stronger acid strength, such as halo lower fatty acids.

However, according to the experimental results of the present inventors, it was confirmed that a portion of the substitute halo fatty acids recommended in the above-mentioned publication decomposes during the reaction and releases hydrogen halide.

Such a reaction system requires the use of expensive Hastelloy, and has the disadvantage that the manufacturing equipment becomes very expensive.

Furthermore, it was discovered that some of these lower oral fatty acids were converted into methyl esters during the reaction. This leads to a decrease in the effective utilization rate of formaldehyde and further to deactivation of the melting medium, which poses a serious problem in practice.

The present inventors have conducted extensive studies to solve the above problems,
The present invention has been completed by discovering that alkylphenols can be produced in good yield under mild conditions at low manufacturing costs without the problem of corrosion of equipment due to strong acids.

That is, the present invention provides a method for producing alkylphenols by catalytically reacting phenols and aldehydes in the presence of hydrogen, in which a catalyst selected from a compound having a sulfonic acid group and a sulfur oxyacid is used. The present invention provides a method for producing alkylphenols using at least one acid and a Group I metal.

The compound having a sulfonic acid group among the acids selected from compounds having a sulfonic acid group and sulfur oxyacids used in the method of the present invention is an organic sulfonic acid and an organic sulfonic acid type cation exchange resin. is used.

Examples of organic sulfonic acids include aromatic sulfonic acids such as paratoluenesulfonic acid, alkylbenzenesulfonic acid, and naphthalenesulfonic acid, and aliphatic sulfonic acids such as methanesulfonic acid.

Specific examples of organic sulfonic acid type cation exchange resins include;
Examples include styrene-divinylbenzene copolymers having sulfonic acid groups, and perfluorinated polymers containing sulfonic acid groups. In the former case, those in which other groups such as alkyl groups and halogens are added to the aromatic nucleus are also within the scope of the present invention. The latter is manufactured by DuPont under the product name "Nafion".
A typical example is one commercially available as J, but it is of course not limited to this.

Sulfuric acid, sulfurous acid, etc. are used as sulfur oxyacids.

All of the above acids used in the present invention have pi(a (2s°C)) of 0.
has the following negative values (J, Amer, chem
, soc,.

2.4801 (1979)).

Group Ⅰ metals used in the method of the present invention include palladium,
Examples include platinum, ruthenium, iridium, nickel, and cobalt, with palladium being particularly preferred.

The above-mentioned Group (1) metal can be used by being contained in the above-mentioned organic sulfone type cation exchange resin or supported on a carbon carrier or the like. The Group Ⅰ metal can be incorporated into the cation exchange resin by conventional loading, ion exchange, etc. operations.

When the Group 1 metal is supported on a carbon carrier or the like, palladium supported on a carbon carrier is particularly preferred.

Examples of the carbon carrier used as a carrier in this case include carbon materials such as activated carbon, carbon black, and graphite, and among these, the use of carbon blank is more preferable. Method 1 for supporting the palladium component on the carbon carrier is not particularly limited, but the palladium component may be supported on the carbon carrier, which has been optionally washed, by any means known per se.

Examples of such loading methods include, for example, loading under reducing conditions with alkali-formalin, loading under liquid phase hydrogen reducing conditions, or loading palladium salts and then using hydrogen or other reducing agents. and other methods (for example, R, Mozingo Organic 5yn
thesis Vol, 26P77 (1946)
(see ).

The palladium raw material used is not particularly limited, but examples include palladium compounds such as palladium chloride, palladium nitrate, palladium hydroxide, palladium acetylacetonate, palladium ammonium chloride (potassium, sodium), and palladium sulfate. be able to.

Palladium chloride is usually used in terms of stability and cost. Palladium chloride is generally dissolved in an aqueous solution of hydrochloric acid. In view of the fact that alkali-formalin reduction generally tends to leave alkali metal ions remaining, in such cases it is preferable to thoroughly wash with water to thoroughly remove CZ-ions, Na, etc. Furthermore, a palladium catalyst supported on a commercially available carbon carrier can also be used, and in this case, it is preferable to wash it with boiling water, dry it, and then re-reduce it in a hydrogen gas stream. The supported amount of palladium can be selected as appropriate, and is, for example, about 0.1 to about 10 wt%, more preferably about 0.1 to about 10 wt%.
For example, a supported amount of 5 to about 5 wt% can be exemplified. The method of the present invention performs the alkylation reaction of phenols in the absence of a solvent or as a reaction solvent using an organic carboxylic acid having a pKa (25°C) of 4 or more or hydrolysis. Although the reaction can be carried out in the presence of a compound that produces the organic carboxylic acid, it is preferable to carry out the reaction in the presence of a reaction solvent. Specific examples of these solvents include saturated fatty acids such as acetic acid and propionic acid, and organic carboxylic acids with electron-donating functional groups such as β-hydroxypropionic acid, and examples of the latter include γ −
Examples include lactones such as butyrolactone, esters such as ethylene diacetate, and n-butyl acetate.

When an organic carboxylic acid with a pKa of less than 4 or a compound that can be hydrolyzed to produce the organic carboxylic acid is used as a solvent,
There are drawbacks such as a lower effective utilization rate of raw material aldehydes.

In the method of the present invention, in addition to the above-mentioned characteristics, it is preferable that the molar ratio of the aldehydes and phenols used as raw materials is adjusted in advance before the reaction is carried out. That is, it is preferable to carry out the reaction at a molar ratio of aldehyde/phenol in the range of 1 to 4. As the molar ratio of aldehyde/phenols becomes smaller than 1, the conversion rate of phenols becomes lower and the rate of by-product of unuseful bisphenols becomes higher. Also, 4.4
'-Methylenebis(2,6-tert-butylphenol) is also produced as a by-product, but this substance is itself a useful antioxidant and a small amount of by-product is acceptable, but it is not the intended compound. Therefore, it is desirable to keep it to a small amount. As the molar ratio of aldehydes and phenols exceeds 4, side reactions in which alcohols are produced by hydrogenation of aldehydes increase, which is undesirable because the selectivity from aldehydes to the desired product ultimately decreases.

The raw material phenols used in the method of the present invention include:
It is capable of nuclear alkylation and therefore has at least a hydrogen atom directly connected to an aromatic nucleus. Such phenols may have various substituents, and may be not only monohydric phenols but also polyhydric phenols. Specific examples include phenol, naphthol, cresol, xylenol, ethylphenol, propylphenol, enol, butylphenol, octylphenol, nonylphenol, dibutylphenol,
Hydrocarbon-substituted phenols such as cyclohexylphenol, phenylphenol, cumylphenol, catechol, resorcinol, hydroquinone, bisphenol A1 dihydroxynaphthalia 1x any polyhydric phenol, alkoxy-substituted phenol such as methoxyphenol, ethoxyphenol, dimethoxyphenol, nonylphenol, bromine These include phenol and halogenated phenols such as dichlorophenol.

The aldehydes used in the method of the present invention include 1-
There are aldehydes with 10 carbons.

Specifically, in addition to formaldehyde, acetaldehyde, and propionaldehyde, paraformaldehyde, trioxane, and paraaldehyde, which generate cholera aldehydes under reaction conditions, are also used.

When the alkylation is methylation, particularly preferred is paraformaldehyde, which also preferably has a low water content.

In the method of the invention, the reaction can be carried out under any pressure.

In general, it can be carried out at a pressure of 1 atm or higher, preferably 1 to 100 atm, and particularly preferably 3 to 50 atm.

The reaction temperature can usually be selected within the range of 50 to 200°C, but is preferably 80 to 150°C from the viewpoint of reaction rate and selectivity.

The most industrially advantageous method of the present invention is to combine one or more acids selected from organic sulfonic acids and sulfur oxyacids as a catalyst with a Group I metal, particularly palladium, on carbon.
Phenols and aldehydes are catalytically reacted in the presence of hydrogen using phenols and aldehydes supported on an elementary carrier.
It is preferable to carry out the reaction in the presence of an organic carboxylic acid having a temperature (s°C) of 4 or more or a compound that can be hydrolyzed to produce the organic carboxylic acid at a molar ratio of aldehyde/phenol in the range of 1 to 4.

In this case, it is possible to reduce the amount of catalyst used to the extent that it is disposable. That is, raw material phenols IK
The amount of sulfur-containing acid such as an organic sulfonic acid and/or a sulfur oxyacid used for 9 is sufficient to be 0.019 or more and 102 or less. Even if the concentration of the sulfur-containing acid becomes higher than this, it is possible to maintain a high reaction yield to some extent by increasing the corresponding amount of Group (I) metal. However, using too large a quantity is undesirable as it leads to a decrease in the yield of the target product and an increase in the amount of catalyst used. In addition, the amount of Group III metal used in the present invention is 0012 or more per 1 raw material phenol.
2 or less. Although it is possible to proceed the reaction smoothly with an amount greater than this, it is not preferable because the hydrogenation reaction of aldehyde, etc. increases.

In the method of the present invention, the desired 2,6-tert-butyl cresol (hereinafter referred to as B
In order to obtain alkylphenols such as (abbreviated as ll'r), the amount of the above-mentioned organic sulfonic acids and sulfur-containing acids such as sulfur oxyacids to be used relative to the raw material phenols, and the amount of Group II metal to be used relative to the raw material phenols. must be used in the above relationship.

The amount of catalyst used above indicates the relationship when the process of the invention is carried out in a batchwise reaction. However, the method of the present invention can also use a Group I metal supported catalyst under continuous flow conditions such as a fixed bed or a fluidized bed. However, in this case, it is necessary to supply the sulfur-containing yellow acid as close to the Group 1 metal catalyst as possible.

The present invention will be explained in more detail by giving examples and comparative examples below.

In addition, in the following examples, 2,6-di-tert-butylphenol (hereinafter abbreviated as DTBP) conversion rate, 2,6-tert-butylphenol (hereinafter abbreviated as DTBP) conversion rate,
ert-butyl-p-cresol (hereinafter abbreviated as T) selectivity and 4,4'-methylenebis(2,6
- Tert-butylphenol (hereinafter abbreviated as BBP) selectivity, bisphenol (hereinafter abbreviated as BP) selectivity, parapormaldehyde (hereinafter abbreviated as PFA) conversion rate, B and E based on paraformaldehyde (T
Selectivity (hereinafter abbreviated as B'HT (PFA) selectivity),
The selectivity of methyl acetate produced by the esterification reaction from methanol produced by the aqueous reaction of paraformaldehyde and acetic acid as a solvent is defined as follows.

(Bf (T selectivity) (B B P selectivity) (BP selectivity) (PFA conversion rate) (BHT (PFA) selectivity) (Methyl acetate selectivity) Example 1 Carbon black (manufactured by Lion Akzo Co., Ltd., product name [Ketjen-ECj, specific surface area: 858/2), 0,4
N NaOH: suspended in 240 ml at 60 °C
After stirring for an hour, it was filtered, washed with 1 ton of boiling water, and dried. The treated carbon black thus obtained was 4°8? 0. I
NNaOH: 100 rr, l and demineralized water: 200 m
A mixture of 1 and 1 liters of liquid was added to make it cloudy (this liquid is called liquid A).

Palladium chloride (PdC6z): 12.0 Of
(7.20 ? as Pd) in concentrated hydrochloric acid 25 ? in a 1 t volumetric flask. was added and dissolved, and demineralized water was added to this to make 1 ooom. This solution contains 72.01 mg of Pd in loml (this is referred to as solution B).

6 rnl of Solution B was added to the AM over 10 minutes with stirring, and after stirring for an additional hour, it was filtered and then washed with 1 t of boiling water. This was resuspended in 400 rug of demineralized water, bubbled with hydrogen for 30 minutes at 70°C with stirring, filtered, washed with 500 WLl of boiling water, dried overnight at 110°C, and reduced to 1 weight. % palladium supported carbon black catalyst was obtained.

DTBP: zo, 6r (10 mmol), PFA containing 120 mmol of formaldehyde: 3.75y, acetic acid: 2og, p-toluenesulfonic acid di 0.0259, 1% by weight palladium-supported carbon black obtained as above. Catalyst: 0.1.5 f was charged in a total of 100 ml autoclave, and the reaction was carried out at 130°C under hydrogen pressure of 30 atm for 1 hour. During this time, the total pressure was kept constant by supplying hydrogen through a pressure regulating valve. After the reaction was completed, the autoclave was cooled in water to obtain a reaction solution separated into two layers: an oil layer containing crystals of the desired 2,6-sheet-tert-butyl-p-cresol and a catalyst layer. Result D of analyzing the reaction solution by gas chromatography and liquid chromatography
TBP conversion rate 84.1%, B) IT selectivity (DTBP standard) 89.3%, BBPBP selectivity 6%, PFA conversion rate 85.1%, B'f (T selectivity (PFA standard) 73.
6%, and methyl acetate selectivity was 5.7%.

Example 2 DTBP: 1o, 3r (so mmol), PFA with 80 mmol formaldehyde: 2°5″?, acetic acid:
102, p-) Luenesulfonic acid: 0.051.5% by weight Palladium-supported activated carbon catalyst: 0°2v in 100ml
The reaction was carried out in the same manner as in Example 1, except that the autoclave was charged and the reaction time was 15 minutes.

As a result of the reaction, DTBP conversion rate was 92.2%, BHT selectivity (
DTBP standard) 94.4%, BBP selection rate 4.6%,
PFAFA conversion rate 83%, BHT selectivity (PFA standard)
69.8%, and methyl acetate selectivity was 18.6%.

Example 3 p-) The reaction was carried out in the same manner as in Example 2 except that sulfuric acid: 0.032 was used instead of luenesulfonic acid.

As a result of the reaction, DTBP conversion rate was 95.1%, BHT selectivity (
DTBP standard) 87.0%, BBP selection rate 11.4%
The PFAFA conversion rate was 89%, the BE (T selectivity (PFA standard) was 61.5%, and the methyl acetate selectivity was 22.1%.

Example 4 Palladium chloride 0.18 f, distilled water 5 or Lt, and a cation exchange resin having a sulfonic acid group (Rohm, USA)
A spherical product (trade name: "Amberlyst 15" manufactured by Ant Haas, 0.4 to 0.5 mm in diameter) was weighed into a flask and stirred at 90°C for 1 hour. Next, while maintaining the temperature at 60° C. and stirring, hydrogen was blown into the suspension at a flow rate of 2017 hours for 2 hours. After cooling to room temperature, the filtered solid was washed and filtered with distilled water and evaporated in a rotary evaporator for 8 hours.
Suction drying was carried out at 0°C for 2 hours to obtain a catalyst of 9.52. Analysis revealed that the cation exchange resin contained 1% by weight of palladium.

The above catalyst o, 3st1DTBP: 1o, 3r (5 mmol), paraformaldehyde 2.51 (80 mmol as formaldehyde (hereinafter abbreviated as FA)), and acetic acid 10F were placed in a 100rrLl autoclave, and the frozen confectionery was pressurized at 30 atm and 130°C. The reaction was carried out with stirring for 1 hour and 30 minutes. During this time, the total pressure was kept constant by supplying hydrogen through a pressure regulating valve (this reaction is referred to as the first reaction). The above reaction was repeated four times in the same manner except that the catalyst used in the first reaction was recovered and used. The results are shown in Table 1 below.

Table 1 Example 5 The reaction was carried out in the same manner as in Example 1 except that the reaction pressure was 9 atm and the reaction time was 1 hour and 30 minutes. As a result, DTBP conversion rate was 91.2%, BHT selectivity (DTBP standard) 87. 4
%, BBP selectivity 9.1%, PFAFA conversion rate 87%,
The BHT selectivity (PFA standard) was 75.6% and the methyl acetate selectivity was 6.3%.

Comparative Example I DTBPlo, 3f (50 mmol), PFA 3.6r containing 102 mmol formaldehyde, acetic acid 52,
Monochlor vinegar powder 3.71.5% by weight Pd supported activated carbon catalyst 0.542 was charged into a 100+il autoclave and reacted at 130°C for 5 hours under hydrogen pressure of 30 atm, resulting in DTB.
P conversion rate 90%, BHT selectivity 87%, BPP selectivity 3
%, PFA conversion rate 100%, BHT selectivity (PFA standard) 39%, methyl acetate selectivity 17%, methanol selectivity as other by-products (PFA standard) 21%, mono-
Methyl chloroacetate was 7%.

Comparative Example 2 PFAl containing 51 mmol formaldehyde, 82
The reaction was carried out in the same manner as in Comparative Example 1, except that the reaction time was 4 hours using B.
HT selectivity (PFA standard) 327o, methyl acetate selectivity 27%, methanol selectivity (PFA) as other by-products
FA standard) 20%, monoQ methyl chloroacetate selectivity 11
%O Examples 6 to 7 The reaction was carried out in the same manner as in Example 5, except that the catalyst shown in Table 2 was used, and the results shown in Table 2 were obtained.

(Margin below) Table 2

Claims (3)

[Claims] (1) In a method for producing alkylphenols by catalytically reacting phenols and aldehydes in the presence of hydrogen, one or more compounds selected from compounds having a sulfonic acid group and sulfur oxyacids are used as catalysts. Acid and Part ■
A method for producing alkylphenols, characterized by using a group metal. (2) The method for producing alkylphenols according to claim 1, wherein the compound having a sulfonic acid group is an organic sulfonic acid. (3) The reaction is carried out without solvent or as a reaction solvent with pKa (2
5° C.) in the presence of an organic carboxylic acid having a temperature of 4 or more or a compound that generates the organic carboxylic acid by hydrolysis, at an aldehyde/phenol DVc molar ratio of 1 to 4. Item 81: A method for producing alkylphenols according to Item 2.