JPS59216852A - Preparation of alicylic diamines - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a raw material for a curing agent of polyamide resin and epoxy resin with preventing side reactions, by subjecting an aromatic diamine to nucleus hydrogenation under specific conditions by the use of a rhodium catalyst in an aqueous medium under hydrogen pressure. CONSTITUTION:An aromatic diamine is subjected to nucleus hydogenation in an aqueous medium in the presence of a rhodium catalyst, and trisodium phosphate or tripotassium phosphate, and one or more of ammonia, fatty secondary amine, and fatty tertiary amine at atmospheric pressure -300kg/cm<2> at 50-250 deg.C preferably at 7-100kg/cm<2> at 65-180 deg.C, to give an alicyclic diamine. The amount of the rhodium catalyst is 0.01-10wt%, based on the aromatic diamine, the amount of water is 0.5-10 times as the catalyst by weight, the amount of trisodium phosphate is 0.1-10wt%, and the amount of ammonia, fatty secondary amine or fatty tertiary amine is 1-20wt%.

Description

[Detailed description of the invention] The present invention relates to a method for producing alicyclic diamines.

More specifically, aromatic diamines are treated with hydrogen in the presence of a rhodium catalyst in an aqueous medium and one or more of trisodium phosphate or tripotassium phosphate and ammonia, aliphatic secondary amines, and aliphatic tertiary amines. The present invention relates to a method for producing alicyclic diamines characterized by carrying out nuclear hydrogenation under pressure.

Alicyclic diamines are important compounds as raw materials for polyamide resins, non-discoloring polyurethane resins, curing agents for epoxy resins, etc.

Conventionally, it has been known to use noble metal catalysts such as rhodium and ruthenium as catalysts for the nuclear hydrogenation of aromatic compounds (hereinafter referred to as nuclear hydrogenation). When used in the production of amines, there is a drawback that a large amount of by-products are produced due to deamination reactions, cambling reactions, etc. It is also well known that the reduction in yield due to these side reactions is greater for aromatic diamines than for aromatic monoamines. Therefore, there are many reports on improvements for efficiently carrying out nuclear hydrogenation of aromatic amines.

For example, West German Patent No. 2745172, West German Patent No. 2502893, and Japanese Unexamined Patent Publication No. 1983-1997 are related to improvement of catalysts.
No. 591 proposes a ruthenium catalyst supported on a chromium-manganese support.

Furthermore, West German Patent No. 2132547 proposes a method using ruthenium chloride treated with pT-(8) with caustic soda and hydrogen peroxide to precipitate crystals.
French patent 1510239 proposes a method of using alkali-treated ruthenium catalyst in combination with calcium carbonate.

Next, side reactions (e.g. deamination, coupling reactions, etc.)
For example, Japanese Unexamined Patent Publication No. Sho/I
No. 8-103545 describes a nuclear hydrogenation method for N-aryl polyamides in which amino groups are acylated.

Of these, the former has problems with versatility and reproducibility due to the use of a special carrier and the need to prepare the catalyst under extremely specific conditions, and the catalyst cost is also extremely high, making it difficult to use from an industrial standpoint. I can't say it's an advantageous method. The reaction conditions for shredding generally require high temperatures and pressures, and require expensive production equipment. The latter requires acylation and hydrolysis after nuclear hydrogenation, which is obviously disadvantageous in terms of the process, and wastewater treatment after hydrolysis is expensive, so it cannot be said to be an economically advantageous method.

As described above, no satisfactory method for nuclear hydrogenation of aromatic amines has been found. The metal (catalyst) used for the catalyst improvements mentioned above is mostly ruthenium, and rhodium, which has high activity for the nuclear hydrogenation of aromatic compounds in general, is used for the nuclear hydrogenation of aromatic amines. There are very few examples in which rhodium is used for nuclear hydrogenation of aromatic diamines. This is Wiley-C1
anterscience, New York, 19
In ``Practical Catalytic Hydrogenation'', p. 71, p. 558, Freifelder argues that ``despite the usefulness of rhodium for the low-pressure reduction of aniline, the hydrogenation of benzenoid compounds containing multiple amino groups is This is understandable given that it is generally not effective against

Based on this recognition, we have conducted extensive research on the nuclear hydrogenation method for aromatic diamines, and as a result, we have found that aromatic diamines can be efficiently nucleated by using a rhodium catalyst under certain specific conditions. They discovered a method for obtaining alicyclic diamines by hydrogenation, leading to the present invention.

It has already been mentioned that the nuclear hydrogenation of aromatic diamines is more likely to cause side reactions than aromatic monoamines and is expected to be difficult to manufacture, but it is also well known that the reduction reaction (nuclear hydrogenation) itself is extremely difficult to proceed. It is being For example, Smith
th) (Catalytic Reactions Vol. 5, p. 212) says, "Reduction of simple aromatic monoamines occurs easily, but more complex amines may be difficult to reduce."

Our results also show that when nuclear hydrogenation of aromatic diamines is carried out using an inert organic solvent such as methanol, which is a very common method for nuclear hydrogenation reactions, the reaction does not complete and stops midway. Oops.

Similar phenomena are observed with other alcohols, inert solvents such as dioxane, or no solvent, and extremely difficult conditions (high temperature, high pressure) are required to complete the reaction. However, the amount of by-products increased and satisfactory results could not be obtained.

However, we have surprisingly found that when nuclear hydrogenation of aromatic 5-aromatic diamines is carried out in an aqueous medium using rhodium as a catalyst, the reaction proceeds easily without stopping midway.

Furthermore, it was found that relatively weak conditions for both temperature and pressure required for the reaction were sufficient.

It was completely unexpected that such a favorable fact would be limited to when water was used as the medium. (Japanese Patent Publication No. 4.8-103545 states that the presence of water is unfavorable because it involves the formation of by-products due to hydrolysis.
It is described in JP-A-57-212145 and the like. ) Next, as a method for preventing side reactions, a method of adding ammonia to the reaction system is known (for example, US Pat. No. 28,223
No. 92, No. 334-7917, No. 3636108), but their side reaction prevention effects are not sufficient.

As a result of our research on methods to prevent side reactions, we found that phosphoric acid 3
It has been found that the presence of one or more of sodium (or potassium), ammonia, aliphatic secondary amine, and aliphatic tertiary amine is highly effective in preventing side reactions. Trisodium (or potassium) phosphate alone has some effect in preventing side reactions, but when used in combination with one or more of ammonia, aliphatic tertiary or secondary amines, a more significant effect appears.

In this case, the aliphatic primary amine had little effect in preventing side reactions.

The present invention will be explained in detail below.

The rhodium catalyst used in the present invention is a carbon or alumina supported catalyst, and the supporting ratio is arbitrary, but it is preferably 1 to 5% supported. Although these supported catalysts are not special, commercially available ones are sufficient. The amount of rhodium catalyst to be used is arbitrarily determined depending on the reaction conditions, but it is preferably used in the range of 0.01 to 10% by weight based on the aromatic diamine.

Next, the amount of water used as a medium is arbitrary, but it is preferably 0.5 to 10 times (by weight) the amount of diamine used, preferably 1.
~5 times. If the diamine exhibits little solubility in water, a suitable dispersant may be used.

The aromatic diamines mentioned in the present invention include o-, m-, p-phenylenediamine, 2.3-, 2.
4-, 2.6-diamittoluene, 4.4'-diaminodiphenylamine, 4. /I'-diaminodiphenyl ether, 4,4'-diamino-3,3'dimethylbiphenyl (orthotolidine), 4,4. Examples include, but are not limited to, '-diaminophenyl sulfone, 4,4'-diamino-3,3' dimethyldiphenylmethane, and the like.

Next, the amount of trisodium phosphate (or potassium) used is:
Although determined by reaction conditions, 0.1 to 10% by weight, 0.5 to 5% by weight, based on normally used diamines.
It is. The amount of ammonia, aliphatic secondary amine, and aliphatic tertiary amine used is 1 to 20% by weight based on the diamines.
A suitable amount is 1 to 5% by weight. Examples of aliphatic secondary amines mentioned here include dimethylamine, diethylamine,
Examples of aliphatic tertiary amines include, but are not limited to, trimethylamine, triethylamine, tripropylamine, tributylamine, and triethanolamine. do not have. Furthermore, when two or more types are used together, the combination ratio can be arbitrarily determined.

The reaction temperature of the present invention ranges from 50°C to 250°C, preferably from 65°C to 180°C. The reaction pressure can range from atmospheric pressure to 300ky/cm2, but is usually 5 to 200ky7cm2. Even better is 7-100! I/m2. The present invention can be carried out using any reaction method including batch reaction, semi-batch reaction and continuous reaction. When the aforementioned diamines are derived from dinitro compounds, the nuclear hydrogenation of the present invention can be carried out simultaneously or in parallel with the reduction of the dinitro compounds to the diamines.

The present invention will be explained in more detail with reference to Examples below.

91 Example 1 108 g of p-phenylenediamine, 2005' of water, and 401 of 5% rhodium-alumina catalyst were placed in an autoclave equipped with a stirring device, and then 1 J of trisodium phosphate and 101 g of triethylamine were added.

After hydrogen replacement, hydrogen pressure 5 Q ky / cm
2, and the temperature was raised to 90°C while stirring. After increasing the temperature, the hydrogen pressure reaches 50! -/cm2, the reaction occurred until hydrogen absorption disappeared. The reaction time was 4 hours and 30 minutes.The reaction mixture was further aged for 30 minutes at the same temperature, and then cooled by shaking at room temperature.The results of gas chromatogram analysis of the reaction solution were as follows.

1.4-Diaminocyclohexane 91.6% (Target) Example 2 0-phenylenediamine 541, water 2 in autoclave
00! i', 4.0 l of a 5% rhodium-carbon catalyst was charged, and then 11 tripotassium phosphate and 5 r of di-10-ethylamine were added. Next, in the same manner as in Example 1, the hydrogen pressure was 5c) ky7t:rr? , and reacted at 120°C for 4 hours. The analysis values of the reaction solution by gas chromatogram were as follows.

1.2-Diaminocyclohexane 935% (Target) Cyclohexylamine 4.1% Aniline 0.2% Secondary amine (high boiling component) 2.2% Example 3, p-phenylenediamine used in Example 1 108g-
A reaction was carried out at 85° C. in the same manner as in Example 1, except that m-phenylenediamine 541 was used instead of 541, and 10 g of 25% ammonia water was used instead of 10 g of triethylamine. The reaction time was 1 hour and 45 minutes. The analysis results by gas chromatogram were as follows.

1,3-diaminocyclohexane 89.0% cyclohexylamine 7,2% aniline
0.3% secondary amine (high boiling component) 3
．． 5% Comparative example 1. (No addition of trisodium phosphate) In Example 3, the reaction was carried out for 2 hours in the same manner as in Example 3, except that trisodium phosphate 1'o1 was not added. The analysis values of the reaction solution by gas chromatogram were as follows.

], 3-diaminocyclohexane 74.7% cyclohexylamine 16.5% aniline
1.0% secondary amine (high boiling component)
78% Comparative Example 2. (Methanol solvent) In Example 3, methanol 200 was used instead of water 2001.
The reaction was continued for 2 hours in the same manner as in Example 3 except that cc was added. A sample of a portion of the reaction solution was analyzed by gas chromatography, and the results showed that 1.3 diaminocyclohexane was 63%, cyclohexylamine was 440%, and aniline was 1.3%.
0%, secondary amine 2.0%, and 30% m-phenylenediamine remained. The reaction was further continued for 2 hours under the same conditions.The analysis results after 1 were: 1,3-diaminocyclohexane 635%, cyclohexylamine 60%,
The proportions were 1.0% of aniline, 4.5% of secondary amine, and 25% of m-phenylenediamine, and it was confirmed that the reaction was extremely difficult to proceed.

Comparative example 3. (Water-containing methanol) Using the spent catalyst used in Comparative Example 2, and using 200 cc of 50% aqueous methanol instead of the 200 cc of methanol used in Comparative Example 2, reaction was carried out in the same manner as in Comparative Example 2 for 4 hours. (Almost no hydrogen absorption was observed after 2 hours of reaction time.) Analysis values from the chromatogram were: 1.3 diaminocyclohexane 53.3%, cyclohexylamine 4.0 qb, aniline 04, secondary amine 8 .6%, m-phenylenediamine 33.7%.

As described above, the reaction was not completed in both the methanol solvent (Comparative Example 2) and the water-containing methanol solvent (Comparative Example 3). In addition, the reaction was carried out using the spent catalyst used in Example 3 under the same conditions as in Example 3 except for the catalyst.
The reaction was completed after only 20 minutes of reaction time.

13-Example 4 122 g of 2,4-diaminotoluene was placed in an autoclave.
, water 200 1.5% rhodium-carbon catalyst 501 was added and then trisodium phosphate 2.0125% ammonia water 20/- was added and the same operation as in Example I was carried out.85
Hydrogen pressure at ℃ is 100! The reaction was carried out for 4 hours at l-/cm2. The analysis result of the reaction liquid by gas chromatogram is l-
Methyl-2,4-diaminocyclo-\xane 94.9%
, methylcyclohexylamine 35%, secondary amine 1
．． It was 6%.

Example 5, 21 dispersant (sodium dodecylbenzenesulfonate) 3,3'-dimethyl-4,4,' - in an autoclave
Diaminobiphenyl (orthotolidine) 507゜5%
Add rhodium-alumina catalyst 4.09-, then add 1.5 J of trisodium phosphate, 5 I of triethanolamine, and 200 J of water and heat at 120°C under hydrogen pressure 1 Q Q kg
/cm2 for 5 hours.

As a result of gas chromad analysis, 3,3'-dimethyl-4,4
'Diaminobiscyclohexane 91.0%, by-product 1
It was 4-90%.

Example 6 A reaction was carried out in the same manner as in Example 5 except that di(3-methyl-4-aminophenyl)methane 501 was used in place of the ortho IJ resin 0I used in Example 5.

The reaction time was 5 hours and 30 minutes.

In analysis using gas chromatography, di(3-methyl-
4-aminocyclohexyl)methane and 46% by-products.

Patent applicant: Nippon Kayaku Co., Ltd. 15- 321-

Claims (1)

[Scope of Claims] Aromatic diamines in an aqueous medium; ■ Rhodium catalyst; ■ Trisodium phosphate or tripotassium phosphate; and the presence of one or more of ammonia, aliphatic secondary amine, and aliphatic tertiary amine. A method for producing alicyclic diamines characterized by nuclear hydrogenation under pressure of hydrogen.