JPS5826844A - Reductive alkylating method of aniline derivative - Google Patents

Abstract

PURPOSE:To alkylate an aniline derivative reductively, industrially and easily in high selectivity and high catalytic activity, by alkylating the aniline derivative with an aldehyde, etc. in the presence of hydrogen, a reducing catalyst consisting of Pd, etc. and a sulfur compound. CONSTITUTION:An aniline derivative except a derivative having an NO2 group, preferably p-aminodiphenylamine, is reduced reductively with an aldehyde or ketone, preferably acetone, methyl isobutyl ketone, etc. in the presence of a sulfur compound which is a liquid or solid at ordinary temperature, hydrogen and a reducing catalyst consisting of Pd or Pt or at 80-190 deg.C and a hydrogen pressure of 10-40kg/cm<2>.G to give an alkylated aniline derivative. Sodium sulfate, sodium thiosulfate, sodium bisulfate, diphenyl sulfone, sulfur-containing dispersing agents, cation exchange resins such as sulfur-containing high polymers, etc. may be used as the sulfur compound.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reductive alkylation of aniline derivatives.

A well-known method is to reductively alkylate an aniline derivative with an aldehyde or ketone in the presence of hydrogen and a reduction catalyst such as a nickel-chromium catalyst or a platinum catalyst. There were drawbacks such as a large amount of alcohol being produced as a by-product, reduction of aromatic rings and hydrogenolysis reaction, and monoselectivity being low.

In addition to the above, many other reduction catalysts have been announced for reductive alkylation, including platinum sulfide catalysts (
Special Publication Showa 42-26196. Special Publication No. 42-24881),
Platinum catalyst for selenization or telluride
2), Rhodium sulfide catalyst (Japanese Patent Publication No. 42-26197)
, barium chloride-containing copper chromium oxide catalyst (Special Publication 1972-
17954), acetic acid-treated copper-chromium-manganese oxide catalyst (Special Publication No. 48-15601. Special Publication No. 4.9-1
7955). Among these, copper-chromium catalysts are inexpensive, but require a relatively high reaction temperature, and reduce aldehydes or ketones as a side reaction, producing a large amount of alcohol, making them industrially disadvantageous. . It has been shown that platinum sulfide, rhodium sulfide, and platinum selenide or telluride catalysts have low aldehyde or ketone reducing activity and good selectivity, but there are difficulties in the method for producing the catalysts.

In order to improve these problems, reductive alkylation in the presence of a sulfur compound has been considered. A reductive alkylation method in a system (Japanese Patent Publication No. 46-28044), a method for reductive alkylation in a system consisting of a nickel catalyst and a free or sulfur-containing compound (Japanese Patent Publication No. 42-7895), and a palladium catalyst and sulfur dioxide. Method for reductive alkylation of amine compounds in a system consisting of (British patent 1
, 098,286-specification) are known. However, in these methods, the activity for reducing aldehydes or ketones is small and the selectivity is excellent, but the activity of nickel catalysts tends to decrease due to sulfur compounds, and in the absence of sulfur compounds, aldehydes or ketones As the activity of reducing sulfur increases, the amount of sulfur compound added must be precise, which is a problem in the bird industry. Although the palladium catalyst itself has a high activity in reducing aldehydes or ketones, its activity is suppressed by the presence of sulfur dioxide, making it an advantageous catalyst for reductive alkylation processes. There are difficulties in accurate confirmation.

Based on these facts, the present inventors conducted studies to improve the drawbacks of conventional methods and to develop a reductive alkylation method that has good selectivity, high catalyst activity, and is easy to implement industrially. We have previously discovered that very good effects can be obtained with a specific combination of catalysts and additives in the reductive alkylation of nitrobenzene derivatives (Japanese Patent Application No. 52,208/1982), but further investigation has been made. The result.

The inventors have discovered that similarly excellent effects can be obtained in the reductive alkylation of aniline derivatives, leading to the present invention.

That is, the present invention uses a sulfur compound that is liquid or solid at room temperature when reductively alkylating an aniline derivative (excluding those having a nitro group) with an aldehyde or ketone in an aqueous system and in the presence of a reduction catalyst made of palladium or platinum. This is a method for reductive alkylation of aniline derivatives, characterized in that the reaction is carried out in the presence of.

In the present invention, sulfur compounds that are liquid or solid at room temperature include free sulfur, and inorganic compounds include:
Examples include sulfites such as ammonium sulfite, sodium hydrogen sulfite, and sodium sulfite, alkali sulfides such as sodium sulfide, ammonium sulfide, and sulfates such as sodium sulfate, sodium hydrogen sulfate, and ammonium sulfate. Examples of organic compounds include mercaptans, sulfides,
Examples include polysulfides, sulfoxides, sulfonium salts, sulfones, sulfinic acids, and sulfonic acids. Also, sulfur-containing natural products or pulp industry by-products such as lignin sulfonic acid, thiolignin and their respective salts,
Sulfur-containing dispersants made of condensates of naphthalene sulfonic acids and formalin, etc., and sulfur-containing amphimolecular compounds such as cation exchange resins are also effective in the present invention.

It is effective if the sulfur compound is added in an amount of at least 1 liter of sulfur to the reduction catalyst.

Aniline derivatives applicable to the present invention include, for example, aniline, alkylaniline (eg, toluidine), alkoxyaniline (eg, anisidine, phenetidine), anyloxyaniline (tertLi! phenoxyaniline).

Arylene diamines (e.g. p-phenylenediamine, 0-phenylenediamine% p-aminodiphenylamine), 4-isopropylaminoaniline, 4-see-
Examples include butylaminoaniline, and p-phinyl diamine and p-aminodiphenylamine are particularly preferred.

As aldehydes or ketones, aliphatic aldehydes,
Examples include alicyclic aldehydes, aromatic aldehydes, dialkyl ketones, arylalkyl ketones, aryl ketones and alicyclic ketones, with acetone, methyl ethyl ketone, methyl isobutyl ketone, mesityl oxide and cyclohexanone being particularly preferred. The amount used is 1-10 molar ratio, preferably 1.1-5 molar ratio, particularly preferably 1.5-3 molar ratio to the aniline derivative.
It is a molar ratio. If the molar ratio is 10 or more, there will be no adverse effect on reductive alkylation, but productivity will decrease and this will be economically disadvantageous. It is also possible to use inert solvents such that a molar excess is used as solvent.

Reduction TI in the present invention! As medium A, diatomaceous earth,
0.1 to 20% by weight of palladium or white waves, preferably o, on an inert carrier such as activated carbon, clay, alumina, etc.
A material supported in the range of 6 to 5 times 1 tq6 is used.

The amount used is 0.001 to 0.2 weight of palladium or platinum based on the aniline derivative, preferably o,
ooa~0.05% by weight. The catalyst after the reaction can be recovered and used as is, but its activity has decreased slightly, so if a new catalyst is added, it can be used in exactly the same way.

The reaction is carried out at a humidity of 50 to 220°C.

The higher the temperature, the shorter the reaction time, but without side reactions.
Since the selectivity is slightly reduced, it is preferable to carry out the reaction at -80 to 190°C. Regarding the hydrogen pressure, although the reaction proceeds at normal pressure, the reaction time becomes longer and it is economically disadvantageous.
The range is positive/-°G.

Next, the present invention will be explained with reference to examples.　　　.

Examples 1-6 A 5001 nl stirred autoclave was charged with 92.1 f/p-aminodiphenylamine and 150.29 f/methyl isobutyl ketone (MIBK). Reduction catalyst 1 in which the sulfur compounds shown in Table 1 and 1% by weight of the sulfur compound were supported on activated carbon.
．． Prepare 4f.

After purging with hydrogen, pressurize to 80~/-·G with hydrogen.

Heated. During the reaction, absorbed hydrogen was constantly replenished to maintain the hydrogen pressure in the system at 80 Kq/-.G.

Hydrogen absorption begins at a reaction temperature of approximately 100°C.

Thereafter, the temperature was maintained at 150°C. Cool the autoclave to room temperature at the time when hydrogen absorption is no longer observed or for 5 hours,
The catalyst was separated by filtration. The F solution was analyzed by gas chromatography and N-1,13-dimethylbutyl-N'
- Yield of phenyl-p-phenylenediamine (6PFD), residual rate of intermediate, and by-product rate of methyl isobutyl carbinol (MIBC) were calculated. The results are shown in Table 1.

Table 1 *l Intermediate: N-1,a-dimethylbutyritene-N'
~Phenyl-p-phenylenediamine *2 By-product rate with respect to charged MIBK *8 Condensate of naphthalene sulfonic acid and formalin Examples 7 to 11 p-aminodiphenylamine 147.4 f.

The procedure was carried out in the same manner as in Examples 1 to 6 except that acetone 189.41 was used and the reaction temperature was 140°C.
The yield of D), the residual rate of the intermediate, and the by-product rate of isopropyl alcohol (IPA) were calculated. The results are shown in Table 2.

Table 2 *1 Intermediate 2N-isopropylidene-N'-phenyl-p-phenylenediamine *2 By-product rate relative to charged acetone

Claims (1)

[Claims] In the reductive alkylation of aniline derivatives (excluding those with a nitro group) with aldehydes or ketones in the presence of a reduction catalyst consisting of hydrogen and palladium or platinum, in the presence of a sulfur compound that is liquid or solid at room temperature. A method for reductive alkylation of aniline derivatives, characterized by carrying out the reaction.