JPH0819024B2 - Method for producing phenol containing alkoxyalkyl group - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a phenol having an alkoxyalkyl group, and more specifically, it is used as an antioxidant, a preservative, and other raw materials for chemical products. The present invention relates to a method for producing a phenol having an alkoxyalkyl group, which is capable of producing a high-yield phenol having an alkoxyalkyl group and is easy to separate a target product and a catalyst.

[Prior Art and Problems Thereof] In general, phenols having an alkoxyalkyl group such as 2,6-di-t-butyl-4-methoxymethylphenol are used as raw materials for antioxidants, preservatives and other chemical products. It has been known.

Conventionally, as a method for producing phenols having an alkoxyalkyl group, phenols such as 2,6-di-t-butylphenol, alcohol and formaldehyde, such as N, N-dimethyl-3,5-diphenol, have been conventionally used. -T
A method for producing by reacting in the presence of a tertiary amine derived from phenols such as -butyl-4-hydroxybenzylamine (Mannich base) has been known.

However, this method has a problem that the yield is about 82%, which is not yet satisfactory, and the production of the target substance and the catalyst are similar to each other, so that the separation of them is not easy.

[Object of the Invention] The present invention has been made based on the above circumstances.

That is, it is an object of the present invention to provide a method for producing an alkoxyalkyl group-containing phenol in which the target product and the catalyst can be easily separated with a high yield.

[Means for Achieving the Object] As a result of earnest studies by the inventor in order to achieve the object, in the presence of a specific tertiary amine, a compound represented by a specific general formula , A phenol having an alkoxyalkyl group can be produced in a high yield by reacting a phenol, an alcohol and an aldehyde, and the target substance and the catalyst can be easily separated and recovered. The present invention has been reached by finding that the catalyst can be reused as it is.

That is, an outline of the present invention for achieving the above-mentioned object is to provide a compound represented by the general formula in the presence of a tertiary alkylamine and / or a tertiary unsubstituted benzylamine. (However, R ⁶ and R ⁷ each represent a hydrogen atom or an alkyl group.) And a phenol represented by the general formula
Reaction of an alcohol represented by R ⁸ OH (where R ⁸ represents an alkyl group) with an aldehyde represented by the general formula R ⁹ CHO (where R ⁹ represents a hydrogen atom or an alkyl group) And a method for producing an alkoxyl alkyl group-containing phenol.

The tertiary alkyl amine has the formula (However, R ¹ , R ² and R ³ represent an alkyl group having 1 to 20 carbon atoms, and R ¹ , R ² and R ³ may be the same or different from each other.) Can be represented.

Examples of the tertiary alkyl amine include N, N
-Diethyl-laurylamine, N, N-diethyl-tridecylamine, N, N-diethyl-palmitylamine, N, N-
Ethyl-dihexylamine, N-methyl-dipalmitylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tricaprylamine, triethylamine. Examples thereof include laurylamine, trimyristylamine, tricetylamine, tristearylamine, and triaralkylamine.

These various tertiary alkyl amines may be used alone or in combination of two or more.

Of the various tertiary alkyl amines, R ¹ , R ² and
R ³ having a lower alkyl group having 1 to 4 carbon atoms, for example, trimethylamine, tripropylamine, tributylamine, N, N-dimethyl-ethylamine, N, N-dimethyl-propylamine, N, N -Dimethyl-butylamine, N, N-diethyl-methylamine, N, N-
Diethyl-propylamine, N, N-diethyl-butylamine, N, N-dipropyl-ethylamine, N, N-dipropyl-butylamine, N, N-dibutyl-methylamine, N, N
-Dibutyl-ethylamine, N, N-dibutyl-propylamine and the like are preferable, and those having a lower alkyl group in which R ¹ , R ² and R ³ are all the same such as triethylamine and tributylamine are particularly preferable.

Next, the tertiary unsubstituted benzylamine has the formula (However, R ⁴ and R ⁵ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.).

Examples of the tertiary unsubstituted benzylamine include N-methyl-N-ethylbenzylamine, N-methyl-N-propylbenzylamine, N-methyl-N-butylbenzylamine, N-ethyl-N-propyl. Benzylamine, N-ethyl-N-butylbenzylamine,
N-propyl-N-butylbenzylamine, N, N-dimethylbenzylamine, N, N-diethylbenzylamine,
N, N-dipropylbenzylamine, N, N-dibutylbenzylamine, N, N-dipentylbenzylamine, N, N-dihexylbenzylamine, N, N-diheptylbenzylamine, N, N-dioctylbenzylamine, N, N-dinonylbenzylamine, N, N-dicaprylbenzylamine, N, N-
Examples thereof include dilaurylbenzylamine, N, N-dimyristylbenzylamine, N, N-benzyldicetylamine, N, N-distearylbenzylamine and N, N-diaralkylbenzylamine. Among these, tertiary unsubstituted benzylamine having a lower alkyl group having 1 to 20 carbon atoms of R ⁴ and R ⁵ is preferable, and N, N-diethylbenzylamine and N, N-dibutylbenzylamine are particularly preferable. .

The tertiary unsubstituted benzylamines may be used alone or in combination of two or more.

In the method for producing a phenol having an alkoxyalkyl group of the present invention, the tertiary alkylamine or the tertiary unsubstituted benzylamine can be used alone, respectively. It can also be used in combination with a tertiary unsubstituted benzylamine.

Examples of the phenols represented by the specific general formula include phenol, o-cresol, m-cresol, p-cresol, ethylphenol, propylphenol, p-tert-butylphenol, p-tert-amylphenol, o-sec. -Amylphenol, p-octylphenol, p-octylphenol, xylenol, p-nonylphenol, o-nonylphenol,
2,6-diisopropylphenol, 2,6-di-tert-butylphenol, di-tert-aminophenol, di-sec
Mention may be made of amylphenol and the like.

Among these, 2,6-di-tert-butylphenol is preferable.

Examples of the alcohol represented by the general formula R ⁸ OH,
For example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, pentanol, pentanol-1, pentanol-2, pentanol-
3,2-methylbutanol-1,2-methylbutanol-1,2-methylbutanol-3,2-methylbutanol-4, dimethylpropanol, hexanol-1, hexanol-2, heptanol-1, heptanol-
2, octanol-1, octanol-2, 4-ethylhexanol-4, 2-ethylhexanol-1, nonanol-1, nonanol-2, nonanol-3, decanol-1, decanol-2, undecanol-1, undecanol- 2, dodecanol-1, tridecanol-
1, tridecanol-2, tetradecanol-1, tetradecanol-2, pentadecanol-1, pentadecanol-2, hexadecanol-1, hexadecanol-2, heptadecanol-1, heptadeca Nord-2,
Octadecanol-1, octadecanol-2, nonadecanol-1, nonadecanol-2, eicosanol-
1, eicosanol-2, heneicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol, nonacosanol, triacontanol,
Examples include Hentria Contanol and Dotria Contanol. Of these, methyl alcohol is preferable.

Examples of the aldehydes represented by the general formula R ⁸ CHO include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeroaldehyde, isovaleraldehyde, methylethylacetaldehyde, trimethylacetaldehyde, n. -Hexaaldehyde, diethylacetaldehyde, dimethylethylacetaldehyde, 2-cyclopentenylacetaldehyde, ethyl-n-butylacetaldehyde, enanthaldehyde and the like.

 Among these, paraformaldehyde is preferable.

In the method for producing a phenol having an alkoxyalkyl group of the present invention, in the presence of the tertiary alkylamine and / or the tertiary unsubstituted benzylamine,
The phenols, the alcohols, and the aldehydes are reacted.

 The above reaction can be represented by the following reaction formula.

(However, R ⁶ , R ⁷ , and R ⁹ represent a hydrogen atom or an alkyl group, and R ⁸ represents an alkyl group.) In the above reaction, a solvent can be used.

The solvent is preferably an alcohol represented by R ⁸ OH, the alcohol R ⁸ OH is reactant in the reaction.

Therefore, in the reaction, it is preferable to add the alcohol R ⁸ OH to the phenols in a large excess.

The amount of the aldehyde used relative to the phenol is 1 to 6 mol, preferably 2 to 4 mol, per 1 mol of the phenol.

If the amount of the aldehyde used is less than 1 mol, the reaction may not proceed, and if the amount used is more than 6 mol, the yield of the phenol having an alkoxyalkyl group may not be improved.

The reaction proceeds at a temperature of 50 to 250 ° C., preferably 70 to 150 ° C., a pressure of 1 to 200 kg / cm ² G, preferably 5 to 100 kg / cm ² G, and a reaction time of 0.5 to 20 hours, preferably Is 1-10
Time.

When the reaction temperature is lower than 50 ° C, the reaction may not proceed sufficiently, while when it is higher than 250 ° C, the activity of the catalyst tertiary alkylamine or tertiary unsubstituted benzylamine decreases. As a result, the desired alkoxyalkyl group-containing phenol may not be sufficiently produced.

When the reaction pressure is lower than 0 kg / cm ² G, the reaction may not proceed at a sufficient rate, while when it is higher than 200 kg / cm ² G, the reaction activity may not be sufficiently enhanced. .

If the reaction time is shorter than 0.5 hours, phenols having an alkoxyalkyl group may not be sufficiently formed, and even if the reaction time is longer than 20 hours, the yield of the phenols having an alkoxyalkyl group does not improve, and the productivity is rather increased. May decrease.

In the method for producing an alkoxyalkyl group-containing phenol of the present invention, since a tertiary alkylamine and / or a tertiary unsubstituted benzylamine that does not approximate the structure of the target substance is used as a catalyst, the tertiary alkylamine It is possible to easily separate the tertiary unsubstituted benzylamine and the alkoxyalkyl group-containing phenols.

EFFECTS OF THE INVENTION The method for producing an alkoxyalkyl group-containing phenol of the present invention is different from the conventional production method in that it does not approximate the production of a phenol having an alkoxyalkyl group as a catalyst. Unsubstituted benzylamine is used.

Therefore, according to the present invention, since the structure of the catalyst that the conventional production method has and the structure of the target phenols having an alkoxyalkyl group are similar, it is difficult to separate them. Is solved efficiently,
Moreover, it is possible to provide an industrially useful method for producing a phenol having an alkoxyalkyl group, which is capable of producing a phenol having an alkoxyalkyl group in a high yield.

Furthermore, since the catalyst used in the method of the present invention can be reused as it is immediately after being separated from the reaction system, the present invention can be said to be an efficient production method also in this respect.

[Examples] Next, the present invention will be described in more detail by showing Examples and Comparative Examples of the present invention.

Example 1 A 250 ml autoclave was charged with 120 mmol of 2,6-di-tert-butylphenol, 100 ml of methanol, 200 mmol of paraformaldehyde and 30 mmol of triethylamine, and the mixture was mixed under the conditions of temperature 125 ° C. and pressure 6 kg / cm ² G. time,
The reaction was performed.

After completion of the reaction, the mixture was cooled to 40 ° C., and the conversion rate and selectivity were determined by gas chromatography.

 The results are shown in Table 1.

(Example 2) The solution after completion of the reaction of Example 1 was cooled to 25 ° C and phenols having an alkoxyalkyl group were separated by filtration as crystals, and the filtrate was put in a 250 ml autoclave and further 2,6 -120 mmol of di-tert-butylphenol, 100 ml of methanol, 200 of paraformaldehyde
The reaction was carried out by supplementing each of them so that the concentration would be mmol.

 The results are shown in Table 1.

(Example 3) The procedure of Example 2 was repeated, except that the solution of Example 1 after the reaction was replaced with the solution of the Example 2 after the reaction.

 The results are shown in Table 1.

(Example 4) The procedure of Example 2 was repeated, except that the solution of Example 1 after the reaction was replaced with the solution of the Example 3 after the reaction.

 The results are shown in Table 1.

(Example 5) The procedure of Example 2 was repeated, except that the solution of Example 1 after the reaction was replaced with the solution of the Example 4 after the reaction.

 The results are shown in Table 1.

Example 6 In Example 1, trinormal amine was used instead of triethylamine, and the reaction temperature was 10
Example 1 except that the reaction pressure was 0 ° C. and the reaction pressure was 2 kg / cm ² G
It carried out similarly to.

 The results are shown in Table 1.

(Example 7) In the same manner as in Example 8 except that benzyldiethylamine was used in place of trinormal butylamine, the reaction temperature was 125 ° C, and the reaction pressure was 6 kg / cm ² G. Carried out.

 The results are shown in Table 1.

(Comparative example) In the autoclave of 1, 500 mmol of 2,6-di-tert-butylphenol, 270 ml of methanol, 800 mmol of paraformaldehyde and 3.0 g of 40% dimethylamine.
(N, N-dimethyl-3,5-di-tert-butyl-4-hydroxybenzylamine (Mannich base) is generated), and the reaction is carried out under conditions of 0.6 kg / cm ² G at 65 ° C. for 3 hours. After that, the reaction was further performed at 80 ° C. for 4 hours.

After completion of the reaction, the mixture was cooled to 40 ° C., and the conversion rate and selectivity were determined by gas chromatography.

 The results are shown in Table 1.

As is clear from Table 1, N, N-dimethyl-3,5-di-t-butyl-4-, which has been conventionally used as a catalyst,
When hydroxybenzylamine was used, both the conversion rate and the selectivity were lower than those of Examples 1 to 11.

Claims (1)

[Claims] 1. A compound of the general formula in the presence of a tertiary alkylamine and / or a tertiary unsubstituted benzylamine. (However, R ⁶ and R ⁷ each represent a hydrogen atom or an alkyl group.) And a phenol represented by the general formula
Reaction of an alcohol represented by R ⁸ OH (where R ⁸ represents an alkyl group) with an aldehyde represented by the general formula R ⁹ CHO (where R ⁹ represents a hydrogen atom or an alkyl group) A method for producing a phenol containing an alkoxyl alkyl group, which comprises: