JPS5973567A - Preparation of indole compound - Google Patents

Abstract

PURPOSE:To prepare the titled compound economically, without lowering the catalytic activity, by the vapor-phase catalytic reaction of an aniline compound with ethylene glycol using a catalyst containing I b-group metal wherein said catalyst is preliminarily subjected to the high-temperature oxidative activation treatment prior to the reaction. CONSTITUTION:A catalyst system containing one or more elements selected from Cu, Ag and Au which are the I b-group elements, as active components, is subjected to the high-temperature oxidative activation treatment prior to the reaction. An aniline compound is made to react with ethylene glycol in vapor phase at 250-500 deg.C in the presence of the above catalyst to obtain the titled compound useful as a synthetic raw material of perfumes and amino acids. The amount of the ethylene glycol is preferably 0.05-1mol per 1mol of the aniline compound. The activation of the catalyst can be carried out e.g. by reducing the catalyst with H2 or CO in dry state at 50-450 deg.C, oxidizing with air, etc. at 350-650 deg.C, and again reducing the product.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing indoles from anilines and ethylene glycols.

More specifically, when producing indoles by subjecting anilines and ethylene glycols as raw materials to a gas phase catalytic reaction in the presence of a group Ib metal-containing catalyst, a catalyst that has been oxidized and activated at a high temperature before the reaction is used. This is a method for producing indoles, characterized by using the following methods.

Indoles are known as raw materials for the chemical industry, and indoles in particular have become important substances in recent years as raw materials for fragrances and amino acid synthesis.

There have been many attempts to synthesize indoles in the past, but all of them had problems such as a large number of by-products, expensive raw materials, and complicated manufacturing processes.

Recently, a catalyst system has been discovered that is effective in the reaction of synthesizing indoles using inexpensive raw materials anilines and ethylene glycols and in a short process. For example, C
u-Cr, Cu-Co, pd/5=o2, Pt/
Examples include S = o2, Cd S, etc., but it has already been revealed that the performance of the reaction can be improved by adding water to the reaction system, carrying out the reaction under pressure, etc. It's west.

After that, as a result of further intensive studies, we found that the catalyst system containing one of the group Ib elements Cu1AQ and Au as an active ingredient was subjected to high-temperature oxidation activation treatment before the reaction. The method of the present invention was achieved by discovering that the stability is increased and the reaction can be carried out over a long period of time without any change over time.

That is, in the method of the present invention, anilines and ethylene glycols are used as raw materials, and in the presence of a group B metal-containing catalyst, gas phase catalytic reaction is carried out to produce indoles. This is a method for producing indoles, which is characterized by using a catalyst that has been subjected to the above.

The amines used in the method of the present invention at ℃ are as follows:
General formula 〇) NN2 (wherein R represents a hydrogen atom, a halogen atom, a hydroxyl group-alkyl group, or an alkoxy group).

In addition, ethylene glycols include ethylene glycol,
Propylene glycol, 1,2-butanediol, 1.
These include 2,4-butanetriol, glycerol, 2,3-butanedio-hediethylene glycol, and the like.

The catalyst used in the method of the present invention is a catalyst system containing as an active ingredient one or more selected from group 1) elements Cu, A9, and Au, and as an element that can be combined with these, B, C, O-M, Al, SL, P, S, C
,,TL, Cr, Mn1F<, Co, NQ,
Zn, Go.

G,, S-e,, S r, Z r, Mo, Ru1
Rh, I'd, C(+, I n.

Sn, Sb, T,, Bo,, La, C4, W, I
r, P t, TI, gate), B=, Th, etc. The aforementioned catalysts may be used alone or in the presence of common carriers such as diatomaceous earth, activated clay, zeolite, silica,
4 (1) is used for alumina, silica-alumina, titania, chromia, thoria, magnesia, calcia, zinc oxide, activated carbon, etc.

As raw materials for group Ib elements, in the case of Cu7i) and Ari,
3- Nitrate, sulfate, phosphate, carbonate, halide, organic acid salt, etc. In the case of Au, chloroauric acid, alkali metal chloroaurate, gold cyanide, alkali metal gold cyanide, etc. Can be used generally.

As a method for preparing the catalyst, the usual kneading method, coprecipitation method, impregnation method, and a method combining the above-mentioned methods can be applied. For example, various raw materials are mixed, a small amount of water is added, and the mixture is kneaded using a kneader or the like. It can be prepared by various methods, such as a method in which various raw materials are made into an aqueous solution, a precipitant is added thereto, and the resulting insoluble precipitate is co-precipitated, a method in which various materials are impregnated into various phases.

The obtained catalyst composition is usually dried at 180° C. or lower, and suitable granulation additives, molding aids, etc. are added and molded, or the catalyst composition is crushed and used as it is.

The catalyst containing the Group Ib element as an active ingredient prepared in this manner is activated by the following method.

Catalyst activation treatment 1, reduction treatment-I: N2, Co1C1 (30H, NH,
, N2H.

In the case of a dry reduction method using 4- or the like, the reduction is carried out in the range of 50 to 450°C. On the other hand, Cl-130H1I-I CHO
In the case of a wet reduction method using lN, H4, amines, etc., the reduction is carried out in the range of -1.0 to 100°C.

2. Oxidation Activation Treatment The catalyst that has been subjected to the reduction treatment in Section 717 is subjected to oxidation treatment using 02, N20, air, etc. at a temperature of 350 to 650°C.

3. Reduction treatment - ■ = The catalyst subjected to the oxidation treatment in section 27 was again treated with N9, Co, CI-f301-1. NH3, N
Reduction is carried out using 2H, etc. in the range of 200 to 500°C, and the reaction is carried out.

The method of the present invention is characterized by the oxidation activation treatment of the catalyst shown in the above 2 items. This high-temperature oxidation activation treatment before the reaction increases the stability of the catalyst and allows the reaction to be carried out over a long period of time without any change over time.

In the method of the present invention, the reaction between anilines and ethylene glycols is carried out in the gas phase in the presence of the catalyst, but any reaction mode such as fixed bed, fluidized bed or moving bed is also possible.

The anilines and ethylene glycols introduced into the reactor are 0 ethylene glycols per mole of aniline.
The range is from 0.05 to 5 mol, preferably from 0.005 to 1 mol.

The amount of introduction of anilines and ethylene glycols, which are raw materials, is 0.01 to 10 hr at liquid hourly space velocity (LH8V).
After being vaporized in an evaporator, it is introduced into the reactor. Further, at that time, water vapor, hydrogen, carbon oxide, carbon dioxide, methane, nitrogen, neon, argon, etc. may be accompanied as a carrier gas. Among them, water vapor, hydrogen, and carbon oxide are preferable because they have the effect of increasing the service life of the catalyst.

The reaction temperature is in the range of 200 to 600°C, preferably 250°C.
~500°C.

The reaction can be carried out under reduced pressure, normal pressure, or increased pressure, but normal pressure or increased pressure is preferable.

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

Example 1 and Comparative Example I Cu(No3)2m3I-r2o 35.0! li'
was dissolved in 100 cc of water to obtain an impregnating solution. Next, 5 Qcc of the aforementioned impregnating solution was added to 40 ml of a commercially available silica carrier (specific surface area: 29 om/'g), and the mixture was allowed to stand for 30 minutes.

After that, it was dried at 120℃ and Cu/'S L
It was used as an O2 catalyst. Two Pyrex reaction tubes each having an inner diameter of 20 mm were filled with 8 CC of the same catalyst, and pretreatment was performed using the following two different methods. After each pretreatment, the internal temperature of the reactor was maintained at 360°C, and the raw material with a molar ratio of aniline and ethylene glycol of 8:1 was converted into Ll-ISV O,2
8 hr', water (1,69/hr) and hydrogen (1,
5Nvhr),! [The reaction was carried out. The results are shown in Table 1.

(2) Pretreatment of Example 1: The temperature was raised to 250° C. in an N2 atmosphere, and 142 was sent for 15 minutes to perform reduction treatment-(2).

Next, the temperature was raised to 500° C. in a N2 atmosphere, and then air was introduced to carry out oxidation activation treatment for 5 hours. N.

After replacement, the temperature was lowered to 360°C, and reduction treatment was performed with I42 -■
and used in the reaction.

(2) Pretreatment of Comparative Example 1 2 The temperature was raised to 250° C. under an N2 atmosphere, and N2 was supplied for 15 minutes to perform a reduction treatment. After that, N2
The temperature was raised to 360°C under circulation and used for the reaction.

7- Note 1) Indole yield is the indole yield based on ethylene glycol.

Example 2 and Comparative Example 2 Al NO329.5g and Pd (420,859 to 100g)
It was dissolved in water of CC to prepare an impregnating liquid. Next, 50 cc of the above-mentioned impregnating solution was added to a commercially available alumina carrier (basicity: specific surface area 220 m/g) 409 and left for 30 minutes.

After that, it was filtered, dried at 120°C, and A 9-P d /Al
A 2O5 catalyst was used. Thereafter, the pretreatment was carried out in the same manner as in Example 1 and Comparative Example 1, and the reaction was carried out. The results are shown in Table 2.

-8 = Table 2 Note 1) Same as Table 1 Example 3 and Comparative Example 3 A9NO, 44, 39 and l-lAuC4・41-120
4.19 was dissolved in 100 cc of water to prepare an impregnating solution. Next, a magnesia phase body (specific surface area 85 mj/'g) was prepared by calcining commercially available basic magnesium oxide at 500 °C.
5Qcc of the above-mentioned impregnating solution was added to 409 and left for 30 minutes. After that, it was dried at 120℃ in the ocean, and
u/′MgO catalyst.

Thereafter, pretreatment was performed in the same manner as in Example 1 and Comparative Example 1,
The reaction was carried out. The results are shown in Table 3.

Table 3 patent applicant Mitsui Toatsu Chemical Co., Ltd. 11-

Claims (1)

[Claims] 1) Using anilines and ethylene glycols as raw materials, I
A method for producing indoles, which comprises using a catalyst that has been oxidized and activated at a high temperature before the reaction, in the production of indoles by gas-phase catalytic reaction in the presence of a group B metal-containing catalyst.