KR20010020308A - Method for producing 4,4'- dihalogendiphenylsulfone - Google Patents

Abstract

The present invention

K ₁ ) an essential component comprising or consisting of a plate silicate having a negatively charged layer neutralized with protons and hardly doped with Lewis acid,

K ₂ ) a catalyst comprising, or consisting of, an acidic H-type zeolite as an essential component, or

K ₃ ) the mixed oxide consists of a combination of (a) an oxide of titanium, zirconium, hafnium, tin, iron or chromium (III) and (b) an oxide of vanadium, chromium (VI), molybdenum, tungsten or scandium, or The mixed oxide is a sulfated or phosphated oxide of group (a) and any of the catalysts comprising or consisting of mixed oxides having acidic centers as essential constituents, which are calcined at 450-800 ° C. after mixing. 4-halophenylsulfonyl chloride of formula (I) in the presence of a catalyst selected from: 4- in liquid phase in the presence of a solid catalyst having an acidic center at high temperature, comprising reacting with chlorobenzene, bromobenzene or fluorobenzene A method for producing 4,4'-dihalodiphenyl sulfone by reacting halophenylsulfonyl chloride with halobenzene.

Formula I

Wherein X is chlorine, bromine or fluorine.

Description

Method for producing 4,4'-dihalogendiphenylsulfone {METHOD FOR PRODUCING 4,4'- DIHALOGENDIPHENYLSULFONE}

The process for preparing 4,4'-dichlorophenyl sulfone from chlorobenzene and 4-chlorophenylsulfonyl chloride according to Scheme 1 is described in a number of references, such as US 2,224,964; DE 701,954; GB 926,291; US 3,334,146; US 3,673,259 and WO 83/04251.

In all cases, homogeneous Friedel-Krafts catalysts such as AlCl ₃ or FeCl ₃ were used in minimal molar amounts. This catalyst cannot be recovered during operation but must be decomposed. This causes problems with the treatment of hydrolyzed aluminum chloride or iron chloride, which are toxic or corrosive wastes respectively.

For this reason, the use of ENVIROCAT® EPZG for the aforementioned reactions has already been proposed in the literature [leaflet sheet 25, "Envirocats Supported Reagents" (E.L. 34H, HS Waissey Norsley Industrial Park South Press, UK). Contract Chemicals Limited, Cote Penrin Road). This catalyst is a montmorillonite catalyst doped with a significant amount of Lewis acid as measured by analysis. This catalyst can be used for heterogeneous catalysis and can be recovered from the reaction mixture by filtration. However, the yields obtained using this catalyst are not satisfactory. Moreover, the hydrogen halide formed by this reaction causes the bleeding of the doped Lewis acid.

WO 96/26787 also discloses that acidic clay based heterogeneous catalysts, for example covering aluminum oxide, silicon oxide, zirconium oxide or titanium oxide, are suitable for alkylation reactions. Clays may be contained in these catalysts only as carriers in which aluminum chloride is used, and the use for sulfonylation reactions is not disclosed or proposed.

The present invention reacts p-halophenylsulfonyl chloride with halobenzene in the presence of a plate silicate having an acidic center as a catalyst but containing little Lewis acid, a zeolite in acidic H form or a mixed oxide having an acidic center. It relates to a process for preparing, 4'-dihalodiphenyl sulfone.

In particular, the reaction of the present invention comprises, for example, immobilizing the catalyst in reactor A, passing a reaction mixture consisting of the starting materials chlorobenzene (1) and 4-chlorophenylsulfonyl chloride (2), and upwards under atmospheric pressure. Recirculating the chlorobenzene (4) through the flow can be carried out continuously as shown in the figure. Reaction temperature is 80-300 degreeC, for example, and excess chlorobenzene is 10 mol. Hydrogen chloride liberated from the reaction mixture is discharged via line (5), and the reaction mixture is transferred via line (3) to distillation column (B) for further purification of product (6) and chlorobenzene to be recycled ( 4) are separated.

Heterogeneous catalysts remain active for a long time. The catalyst can be reactivated, for example, by burning in air above 450 ° C. The new method for this is particularly advantageous economically and environmentally compared to conventional synthesis.

It is a first object of the present invention to provide an economical and ecologically advantageous heterogeneous catalyst for producing 4,4'-dichlorophenyl sulfone, which is capable of producing the target compound in good yield and which is readily available and recoverable.

Applicant believes that this first purpose

By reacting 4-halophenylsulfonyl chloride with halobenzene in the liquid phase in the presence of a solid catalyst having an acidic center under high temperature, for example

K ₁ ) a catalyst comprising or consisting of a plate silicate having a negatively charged layer neutralized with protons as an essential component, rarely doped with Lewis acid,

K ₂ ) a catalyst comprising or consisting of zeolites of the acidic H form as essential components, or

K ₃ ) the mixed oxide consists of a combination of (a) oxides of titanium, zirconium, hafnium, tin, iron or chromium (b) and (b) oxides of vanadium, chromium (VI), molybdenum, tungsten or scandium, or The mixed oxide is a sulfated or phosphated oxide of group (a) and any of the catalysts comprising or consisting of mixed oxides having acidic centers as essential constituents, which are calcined at 450-800 ° C. after mixing. Reacting 4-halophenylsulfonyl chloride of formula (I) in the presence of a catalyst selected from chlorobenzene, bromobenzene or fluorobenzene to produce 4,4'-dihalodiphenyl sulfone having the same or different halogen It was found that this can be achieved by the method.

Wherein X is chlorine, bromine or fluorine.

"Almost doped with Lewis acids" (group K ₁ ) in the present invention means that no or no Lewis acids were used in the plate silicates to obtain catalytic activity by these acids. Acidic centers of plate silicates refer to Bronsted centers formed on plate silicates with excess negative charge by exchanging metal ions with protons.

Thus, K ₁ ) a plate silicate hardly doped with soldier Lewis acid is a silicate comprising less than 1% by weight Lewis acid based on plate silicates, especially plate silicates containing little or no Lewis acid transition metals used separately.

The plate silicates of the K ₁ ) group to be used according to the invention are especially aluminum silicates. They belong to clay minerals and consist of SiO ₂ tetrahedra and Al ₂ O ₃ octahedral layers, with some of the silicon in the tetrahedral layer being replaced by trivalent cations, preferably aluminum, and some of the aluminum in the octahedral layer It is replaced by a divalent cation, preferably magnesium, to form a negative charge layer.

Negative charge plate silicates exist as natural minerals such as montmorillonite, bare miclite, hectorite, or can be prepared synthetically.

A more detailed description is given in Z.M. Thomas and W.Z. Thomas, Principles and Practice of Heterogeneous Catalysis, 1997, Vetc. ISBN 5-527-29239-8, p 347 ff.

However, it is preferable to provide it with the natural mineral montmorillonite converted to H form by treatment with acid.

An example is montmorillonite having a layer charge of about 0.6 to 0.2 per formula unit, ie Na _0.33 {(Al _1.67 Mg _0.33 ) (OH) ₂ [Si ₄ O ₁₀ ]}.

The exchangeable cations, usually alkali or alkaline earth metal ions, in protons as natural minerals or as composites can be exchanged for protons to partially or fully neutralize the negative charge with the protons.

Since plate-like silicates containing protons instead of alkali or alkaline earth metal ions are less thermally stable, column clays which support the layers with respect to each other can also be used. Methods for producing such pillar clays are described in Figuras, Catal. Rev. Sci. Eng. 30 (1988) 457 or Jones, Catal. Today 2 (1988) 357.

Specific examples of plate silicates having a negatively charged layer neutralized by protons include montmorillonite, bare miclite and hectorite.

K ₂ ) zeolites to be used as catalysts of the group are described in WM Meier, DH Olson, Ch. In the form of MFI, MEL, BOG, BEA, EMT, MOR, FAU, MTW, LTL, NES, CON or MCM-22 structures according to the structural classification disclosed in Baerlocher, Atlas of Zeolite Structure Types, Elsevier, 4th edition, 1996 Zeolite in acidic H form.

Structural Forms It is preferred to be provided in the acidic H form of 12 ring zeolites of BETA, Y, EMT and mordenite and 10 ring zeolites of pentasil form. In addition to elemental aluminum and silicon, zeolites may contain boron, gallium, iron or titanium in the mold. Furthermore, it may be partially substituted with IB, IIB, IIIB, IIIA or VIIIB elements and lanthanide elements.

Specific examples include ZBM-20, Fe-H-ZSM5, Sn-beta zeolite, beta zeolite, Zr-beta zeolite, H-beta zeolite, H-mordenite, USY, Ce-V zeolite, GY zeolite, Ti / B- Beta zeolite, B-beta zeolite or ZB-10.

Zeolites of the acidic H form and their preparation are disclosed in detail in the literature. To this end, reference is made to the abstract of R. Szostak, Handbook of Molecular Sieves, van Nostrand Reinhold, New York, ISBN 0-442-31899-5, which is hereby incorporated by reference.

The metal oxide of the K ₃ ) group to be used in the present invention is a super acid mixed oxide particularly disclosed in the literature. See, eg, RJ Gillespie, Acc. Chem. Res. 1, (1968) 202 and RJ Gillespie and TE Peel, Adv. Phys. Org. Chem. 9 (1972).

Specific superacid metal oxides that can be used in the reactions of the present invention as catalysts of the K ₃ ) group are disclosed in Kazushi Arata in Applied Catalysis A: General 146 (1996) 3-32 (for the reaction of butene and pentane). This document is cited for reference to super acid metal oxides and their preparation.

Useful sulfated or phosphated metal oxides of group (a) are, in particular, phosphated or sulfated zirconium oxide or titanium oxide, which may include additional elements such as iron, cobalt or manganese.

Preferred sulfated or phosphated catalysts include the following.

ZrO ₂ SO ₄ [S content 0.5-4 mol%]

ZrO ₂ P ₂ O ₅ [P ₂ O ₅ content 3-20 mol%]

Fe ₂ O ₃ P ₂ O ₅ [P ₂ O ₅ content 3-20 mol%]

Co / Mn / ZrO ₂ SO ₄ [S content 0.5-4 mol%; Co / Mn content of 0.1 to 5 mol%]

Fe / Mn / ZrO ₂ SO ₄ [S content of 0.5 to 4 mol%; Fe / Mn content of 0.1 to 5 mol%]

It is preferable to provide zirconium, titanium, iron, tin or chromium (III) as a super acid mixed metal oxide of the groups (a) and (b) containing tungsten or molybdenum.

Specific examples include TiO ₂ WO ₃ , Fe ₂ O ₃ WO ₃ , ZrO ₂ MoO ₃ , ZrO ₂ WO ₃ , Cr ₂ O ₃ WO ₃ , WO ₃ TiO ₂ , TiO ₂ WO ₃ or SnO ₂ WO ₃ SiO ₂ . and the molar ratio of group (a) to group (b) oxides is generally from 70:30 to 90:10.

The reaction of the invention is generally carried out at 80 to 300 ° C, preferably at 110 to 220 ° C, in particular at 130 to 200 ° C.

The reaction may be carried out at a high pressure of up to 50 bar, preferably up to 30 bar, but is generally carried out in a closed vessel under atmospheric pressure or under autogenous pressure of the reaction mixture.

In a preferred embodiment, 4,4'-dichlorophenyl sulfone is prepared by reacting 4-chlorophenylsulfonyl chloride with chlorobenzene.

The starting material chlorobenzene is generally used in molar excess of 1 to 100, preferably 5 to 20, in particular 5 to 15, based on the amount of excess, such as chlorophenylsulfonyl chloride.

Chlorobenzene acts as a solvent. Alternatively, other solvents such as hydrocarbons, preferably hydrocarbons, may be added to achieve the desired reaction temperature at atmospheric pressure.

The catalysis is generally carried out in the liquid phase as a suspending process, or preferably in a fixed bed catalyst in a continuous flow reactor, in which the free hydrochloric acid is released and the reaction mixture containing the product is distilled off during operation. After fractional distillation with product, unreacted chlorobenzene and solvent (if used), the unreacted chlorobenzene is recycled to the reaction.

4,4'-dichlorodiphenyl sulfone is purified by conventional methods such as solvent crystallization from toluene, chlorobenzene or methanol. Based on the p-chlorophenylsulfonyl chloride used, a theoretical yield of 50-95% and very good purity can be obtained.

K ₁ ) Use of group catalyst

Example 1

1 g of acid treated (protonated) montmorillonite (without Lewis acid transition metal applied separately) obtained from Sudchemy (K1O) is added as catalyst to 0.1 mole of 4-chlorobenzenesulfonyl chloride and 1 mole of chlorobenzene, The mixture was heated to 200 ° C. in a closed autoclave. After 6 hours of reaction time, the autoclave was cooled and the pressure was released to filter the contents of the reactor to separate from the catalyst. Excess chlorobenzene was distilled off and the residue analyzed. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield of 4,4'-dichlorodiphenyl sulfone was theoretically 92%.

Example 2

1 g of catalyst KSF (montmorillonite impregnated with H ₂ SO ₄ ) obtained from Schedmie is added to 0.1 mole of 4-chlorobenzenesulfonyl chloride and 1 mole of chlorobenzene, and the mixture is heated to 200 ° C. in a closed autoclave. . After 6 hours of reaction time, the autoclave was cooled down, the pressure was lowered and the contents of the reactor were filtered off to separate from the catalyst. Excess chlorobenzene was distilled off and the residue analyzed. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield of 4,4'-dichlorodiphenyl sulfone was theoretically 91%.

Example 3

A mixture of 4-chlorobenzenesulfonyl chloride and chlorobenzene in a 1:10 ratio was passed upwardly through a tubular reactor charged with the catalyst of Example 1 using a pressure pump. The liberated HCl gas was discharged at the top of the reactor and passed through a waste gas scrubber. The crude reactor eluate was collected and excess chlorobenzene was distilled off. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield was theoretically 92%.

K ₂ ) Use of group catalyst

Example 4

1 g of beta zeolite as catalyst was added to 0.1 mole of 4-chlorobenzenesulfonyl chloride and 1 mole of chlorobenzene, and the mixture was heated to 200 ° C. in a closed autoclave. After 6 hours of reaction time, the autoclave was cooled down, the pressure was lowered and the contents of the reactor were filtered off to separate from the catalyst. Excess chlorobenzene was distilled off and the residue analyzed. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield of 4,4'-dichlorodiphenyl sulfone was theoretically 91%.

Beta zeolite was obtained as follows.

β zeolite (zeticone, zeolite-beta, composition: SiO ₂ = 91%, Al ₂ O ₃ = 7.8%, Na ₂ O = 0.5%, K ₂ O = 0.7%, BET surface area = 700 m ² / g, 220 g of pore size Å = 7.6 × 6.7; 5.5 × 5.5, particle size 0.2-0.5 μm) were mixed with 5% Walocel® and 230 g of water and charged into the kneader for 45 minutes. The material was then molded at a pressure of 70 bar to give a 2 mm extrudate. The extrudate was dried at 110 ° C. and calcined at 500 ° C. for 16 hours.

195 g of these extrudate were exchanged with 3 L of 20% strength NH ₄ Cl solution at 80 ° C. for 2 hours and then washed with 10 L of water. Then, a second exchange was carried out at 80 ° C. for 2 hours with 3 L of another 20% strength NH ₄ Cl solution and the product was washed to remove Cl. The product was dried at 110 ° C. and then calcined at 480 ° C. for 5 hours.

Example 5

1 g of Zr-beta zeolite was added as a catalyst to 0.1 mole of 4-chlorobenzenesulfonyl chloride and 1 mole of chlorobenzene and the mixture was heated to 200 ° C. in a closed autoclave. After 6 hours of reaction time, the autoclave was cooled, the pressure was lowered, and the contents of the reactor were filtered off to separate from the catalyst. Excess chlorobenzene was distilled off and the residue analyzed. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield of 4,4'-dichlorodiphenyl sulfone was theoretical 95%.

Zr-beta zeolite was obtained as follows.

50 g of beta zeolite were heated under nitrogen in a rotary tube oven at 380 ° C. for 2 hours. After cooling to room temperature, 8.9 g of ZrCl ₄ were added as a powder. The mixture was heated to 460 ° C. in 25 minutes and maintained at this temperature for 2 hours (N ₂ stream 10 L / hr). The product was then calcined at 550 ° C. for 3 hours.

Example 6

A mixture of 4-chlorobenzenesulfonyl chloride and chlorobenzene in a 1:10 ratio was passed upwards through a tubular reactor charged with beta zeolite catalyst using a pressure pump. The liberated HCl gas was discharged at the top of the tubular reactor. The crude reaction eluate was collected and excess chlorobenzene was distilled off. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield was theoretically 91%.

Example 7 and Example 8

Example number catalyst yield(%) 7 ZBM-20 89 8 Fe-H = ZMS-5 88

The results shown in Table 1 were obtained using the procedure described in Example 4 and the catalysts are shown in Table 1.

The catalysts of Example 7 and Example 8 were obtained as follows.

ZBM-20

273 kg of water glass (Wilner) and 252 kg of 56% strength hexamethylenediamine solution were placed in an autoclave. Then 31.1 kg iron sulfate, 20.6 kg sulfuric acid (98% strength) and 425 kg water were added with stirring at 50 ° C., then the mixture was stirred for 6 hours. The resulting gel was then aged for 11 hours without stirring and heated to 160 ° C. at a stirrer speed of 30 rpm. Upon reaching this temperature, the mixture was stirred at 18 rpm for another 94 hours. The crystallized product was filtered off, washed with water, dried and calcined.

FeZSM-5

100 g of H-ZSM-5 was suspended in 200 ml of water. Then the addition of FeCl ₂ .4H ₂ O 70 g solution in 200 ㎖ water and the mixture was stirred at room temperature for 24 hours. The product was filtered, washed to remove chlorine, dried at 110 ° C. and calcined at 550 ° C. for 3 hours.

K ₃ ) Use of group catalyst

Example 9

a) catalyst preparation

100 g of ZrOCl ₂ (MV = 178, 0.56 mol) was dissolved in 1000 mL of water. Then Zr (OH) ₄ hydrate was precipitated at room temperature with 25% strength NH ₃ solution 100 ㎖. The precipitate was neutralized by filtration and washing with water. The product was stirred with 300 ml of 1 NH ₂ SO ₄ (0.3 mol = 0.6 valence) for 1 hour and then filtered. The precipitate was dried at 110 ° C. for 24 hours and then calcined in air at 625 ° C. for 2 hours.

b) reaction

1 g of ZrO ₂ SO ₄ catalyst was added to 0.1 mole of 4-chlorobenzenesulfonyl chloride and 1 mole of chlorobenzene, and the mixture was heated to 200 ° C. in a closed autoclave. After 6 hours of reaction time, the autoclave was cooled down, the pressure was lowered, and the contents of the reactor were filtered off to separate from the catalyst. Excess chlorobenzene was distilled off and the residue analyzed. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield of 4,4'-dichlorodiphenyl sulfone was theoretically 91%.

Example 10

a) catalyst preparation

53 g tungstic acid and 112 g solution of 25% strength NH ₃ solution were added to 200 g TiO ₂ powder. This mixture was kneaded for 150 minutes and dried at 120 ° C. for 12 hours. The product was passed through a sieve and calcined at 675 ° C. for 2 hours.

b) reaction

1 g of TiO ₂ WO ₃ catalyst of (a) was added to 0.1 mole of 4-chlorobenzenesulfonyl chloride and 1 mole of chlorobenzene and the mixture was heated to 200 ° C. in a closed autoclave. After 6 hours of reaction time, the autoclave was cooled down, the pressure was lowered, and the contents of the reactor were filtered off to separate from the catalyst. Excess chlorobenzene was distilled off and the residue analyzed. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield of 4,4'-dichlorodiphenyl sulfone was theoretically 90%.

Example 11

A mixture of 4-chlorobenzenesulfonyl chloride and chlorobenzene in a 1:10 ratio was passed through a tubular reactor (5 cm in diameter and 50 cm in length) filled with ZrO ₂ SO ₄ catalyst using a pressure pump. The liberated HCl gas was discharged at the top of the tubular reactor and passed through a waste gas scrubber. The crude reaction eluate was collected and excess chlorobenzene was distilled off. The conversion of 4-chlorobenzenesulfonyl chloride was complete and the yield was theoretically 91%.

Examples 12-15

Similar results were obtained following the procedure set forth in Example 11 using the mixed oxides of Table 2.

Example catalyst yield[%] 12 Co / Mn / ZrO ₂ SO ₄ 88 13 Fe ₂ O ₃ WO ₃ 86 14 ZrO ₂ MoO ₃ 85 15 SnO ₂ WO ₃ SiO ₂ 91

The catalyst of Examples 12-15 was prepared as follows.

Co / Mn / ZrO ₂ SO ₄

Amorphous Zr (OH) ₄ hydrate (prepared in Example 9) _{CO (NO 3) 2, Mn} (NO 3) 2 and (NH _{4) 2} SO ₄ was impregnated with the solution. The product was concentrated on a rotary evaporator and then calcined at 625 ° C. for 2 hours.

Fe ₂ O / WO ₃

FeO (OH) was precipitated from NH ₃ and Fe (NO ₃ ) ₃ solution. The precipitate was filtered off and impregnated with (NH ₄ ) ₂ WO ₄ solution in water. The product was evaporated and calcined at 550 ° C. for 2 hours. The WO ₃ content of the product was 20%.

ZrO ₂ / MoO ₃

Amorphous Zr (OH) ₄ hydrate (prepared as in Example 9) was impregnated with water (NH _{4) 2} MoO ₄ solution. The product was evaporated and calcined at 600 ° C. for 2 hours. MoO ₃ content was 5%.

SnO ₂ / SiO ₂ / WO ₃

A 0.25 mol solution of SnCl _{4 in} 300 mL of water was added to 0.25 mol of SiO ₂ salt. Then a 0.25 molar solution of (NH ₄ ) ₂ WO _{4 in} 200 mL water was added. 1 liter of water was added to precipitate the gel. The precipitate was aged for 24 hours, filtered and dried at 110 ° C. The product was calcined at 700 ° C. for 5 hours.

The K ₃ ) group catalyst to be used according to the invention provides a significantly improved yield compared to the ENVIROCAT EPZG catalyst mentioned earlier.

Claims (15)

K ₁ ) an essential component comprising or consisting of a plate silicate having a negatively charged layer neutralized with protons and hardly doped with Lewis acid, K ₂ ) a catalyst comprising, or consisting of, an acidic H-type zeolite as an essential component, or K ₃ ) the mixed oxide consists of a mixture of (a) an oxide of titanium, zirconium, hafnium, tin, iron or chromium (III) and (b) an oxide of vanadium, chromium (VI), molybdenum, tungsten or scandium, or The mixed oxide is a sulfated or phosphated oxide of group (a) and any of the catalysts comprising or consisting of mixed oxides having acidic centers as essential constituents, which are calcined at 450-800 ° C. after mixing. 4-halophenylsulfonyl chloride of formula (I) in the presence of a catalyst selected from: 4- in liquid phase in the presence of a solid catalyst having an acidic center at high temperature, comprising reacting with chlorobenzene, bromobenzene or fluorobenzene A process for preparing 4,4'-dihalophenyl phenyl sulfone by reacting halophenylsulfonyl chloride with halobenzene. Formula I Wherein X is chlorine, bromine or fluorine. The method of claim 1, wherein the K ₁ ) group catalyst used is an aluminosilicate in which a part of silicon is substituted with aluminum and / or a part of aluminum is substituted with magnesium to prepare 4,4′-dihalodiphenyl sulfone. How to. The method of claim 1, wherein the K ₁ ) group catalyst used is montmorillonite. 4,4 ', wherein the K ₂ ) group catalyst used is a zeolite of structural form MIF, MEL, BOG, BEA, EMTP, MOR, FAU, MTW, LTL, NES, CON or MCM 22. A process for preparing dihalodiphenyl sulfone. A 4,4'-dihalodiphenyl sulfone according to claim 1, wherein the K ₂ ) group catalyst used is a 12 ring zeolite of structural form BETA, Y, EMT or mordenite or 10 ring zeolite of pentasil type. How to. The method of claim 1, wherein the catalyst of the K ₃ ) group used is a super acid mixed oxide. 4. The 4,4'-dihalodi of claim 1, wherein the K ₃ ) group catalyst used comprises oxides of group (a) of group (a) in a molar ratio of 70:30 to 98: 2. Process for preparing phenyl sulfone. The method of claim 1, wherein the chlorobenzene is reacted with 4-chlorophenylsulfonyl chloride to form 4,4'-dichlorophenyl sulfone. The method of claim 1, wherein the reaction is performed at 100 to 250 ° C. and atmospheric pressure to 50 bar. The process according to claim 1, wherein the reaction is carried out at atmospheric pressure at the boiling point of the reaction mixture. The process according to claim 1, wherein the reaction is carried out at autogenous pressure of the reaction mixture. The process according to claim 1, wherein halobenzene is used in excess. The method for preparing 4,4'-dihalodiphenyl sulfone according to claim 1, wherein the molar ratio of chlorobenzene based on 4-chlorophenylsulfonyl chloride is 1 to 100. The process according to claim 1, wherein the catalyst is arranged in a fixed bed. The process of claim 1, wherein the reaction is carried out continuously and excess halobenzene is recycled into the reaction.