JPS5881443A - Catalyst for nuclear chlorination of alkylbenzene - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a catalyst for nuclear chlorination, tlcTII4T, which has excellent selectivity for the p-position of alkylbenzene.

Nuclear S compounds of alkylbenzenes are useful as raw materials for various St organic synthetic chemicals including medicines and agricultural products, and are especially useful for Kp-
There is a large demand for chloroalkylbenzene, such as ζfp-tetratoluene.

However, in the conventional nuclear chlorination reaction, which involves chlorination with chlorine gas using a Lewis acid such as antimony chloride, ferric chloride, or aluminum chloride as a catalyst, 0-OR alkylbenzene is mainly produced. In addition, Km-rep-body polychlorinated products are also produced as by-products,
It was not possible to produce p-chloroalkylbenzene with a selectivity of 40 tatami or more.

Therefore, in order to produce p-chloroalkylbenzene in good yield, various catalysts have been developed. For example, in a method using Lewis acid and sulfur or selenium as a catalyst, p-
-Ryan is obtained with a selectivity of 45 to 52 sounds (for example,
Japanese Patent Publication No. 50-44009, U.S. Patent No. 40514
4, etc.), p-chloroalkylbenzene can be obtained with a selectivity of 55 to 60% in a method using a Lewis acid and a thianthrene compound as a catalyst (for example, JP-A No. 52
-19630 Publication, US Patent $14031147
No. 4, etc.), Lewis acid and 7.・In the method using the Nohosatin compound as a catalyst, p-chlorotetraalkylbenzene can be obtained with a selectivity of 50 to 64 yen (for example, JP-A-56-5139, JP-A-54-110630).
However, these catalysts are still not fully satisfactory as catalysts for the selective production of p-Ritaroalkylbenzene, and there has been a desire for a catalyst that exhibits even higher selectivity.

In view of the current situation, the present inventors have conducted extensive research to provide a catalyst for nuclear chlorination of alkylbenzene that has excellent selectivity for the p-position.

Surprisingly, if a chemically modified Si11 gel with an aniline conductor, a sulfonamide conductor, or a pencil derivative is used as a catalyst, the p
-Discovered that chloroalkylbenzene could be produced,
Based on this knowledge, we have completed the present invention.

(In the formula, m represents silica gel, R is a hydrogen atom t
t represents an alkyl group, where X is a sulfonyl group and m is a methylene group. O represents an integer of 1, Otori is 1
This is a catalyst for nuclear chlorination of alkylbenzene made of chemically modified silica gel represented by ◎ or ◎, which represents an integer of 2.

The chemically modified silica gel of the present invention, which is represented by the general formula (IJ), is obtained by applying 3-(N-alkyl)amitube p-pyltriethoxysilare in an inert solution such as benzene to the chemically modified silica gel for chromatography. Then, a chemically modified silica gel represented by the general formula 1%() (in the formula, M and R represent the same meanings as above) was obtained. In the presence of a diluent.

(In the formula, Y is an atom atom f Table L s X e m and l represent the same meanings as above.) Nitrohydrogenated benzene, nido pbenzenesulfonylpalite! 〇1゜(IJ) is obtained by reacting nitropentyl halide.
) The chemical modification shown by 17:jJ gel is
oo ttHt L < is present in a proportion of 100 to 500 t, and chlorine gas is introduced at a temperature below the boiling point of the reaction mixture. If the temperature is too high, the amount of polychlorinated products produced will be large (and the yield of p-chloro compound will decrease, which is undesirable.On the other hand, the reaction can be carried out at a low temperature of minus several tens of degrees Celsius or lower,
Although the selectivity of the zaa form is low, the reaction rate is slow and uneconomical, so it is usually carried out at a temperature of 0 to 80°C, but industrially it is appropriate to carry out the reaction at a temperature of 20 to 70°C. What is the pressure of the cumulative gas?

The reaction is usually carried out under normal pressure, whether under normal pressure, increased pressure, or reduced pressure.

As the alkylbenzene to be nuclear chlorinated using the catalyst of the present invention, benzene monosubstituted with various straight-chain and branched-chain alkyl groups can be used, but in particular, benzenes having an alkyl group having 1 to 4 carbon atoms can be used. preferable.

By using the catalyst IIj& of the present invention, it is possible to suppress the chlorination of the 〇-position of alkylbenzene and efficiently chlorinate the p-position, and the raw WL of m-chloro and polychlorinated compounds is extremely small. Furthermore, the catalyst of the present invention does not lose its activity even after repeated use and is durable, making it suitable for the industrial production of p-chloro derivatives of alkylbenzenes such as toluene, and its industrial value. Mouth which is expensive? ! The present invention will be explained in more detail with reference to EK examples.

(Example 1) Cumene α6t (5 mmol
) 8 and catalyst (1) [R Peng H in the general formula (υ)
+
0.35 # (5 m mol) of chlorine in 15 d of carbon tetrachloride
was added dropwise, and the mixture was reacted at 30° C. for 1 hour. After the reaction, the catalyst was removed, washed with sodium bicarbonate, dried, and analyzed by gas chromatography. As a result, the production ratio of monochlorocumene was 4-chlorocumene/4-chlorocumene/
The 2-chlorocumene ratio (''/) was -2.09 [Comparative Example 1] (method described in JP-A-56-5159).Equipped with a stirrer, a thermometer, a gas blowing pipe, and a reflux condenser. Cumene 4801 in a 1T-four-loaf flask
．． 2 t of antimony trichloride and 2 t of phenoxatine were taken and heated to about 50°C in a water bath while stirring, until the temperature became constant.

Chlorine gas is introduced at a rate of 300 m/j and the reaction temperature is maintained at 50-55'0 with a water bath. The reaction was stopped by introducing chlorine gas for 5 hours, and one reaction solution was analyzed by gas chromatography. As a result, the composition of the produced monochlorocumene was found to be 4-chlorocumene/2-ri plocumene ratio (/,)-1.
◎ (Example 2) Catalyst (1) of Example 1 was converted to catalyst (2) [the general formula (IJ
In R-H+ X-80m+m-1+ 11-2
The reaction was carried out under the same conditions as in Example 1 except that the reaction solution was replaced with 4-chlorocumene and
The 2-ri a locumen ratio (plo) was -2,00.

[Example 3] The catalyst i1 of Example 1 (11 was replaced by the catalyst (3) [the general formula (
Rm) I, mxOe n=2+ 1 exchange position 2 at υ
．． The reaction was carried out under the same conditions as in Example 1, except that the reaction mixture was replaced with [4-]. As a result of gas chromatograph analysis,
The reaction solution composition was 4-chlorocumene/2-chlorocumene ratio (plo) -156.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the structure of the chemically modified silica gel claimed in the claims. Figure w42 is a schematic diagram of the reaction between cumene and chlorine using a chemically modified silica gel catalyst in Example 1. Patent applicant Ipara Namical Industries Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] (In the formula, m represents a hydrogen atom or an alkyl group, X represents a sulfonyl group or a methylene group, m represents an integer of 0 or 1, and n represents a 1 or 2 177F
Catalyst for nuclear chlorination of alkylbenzene consisting of gel