GB1572916A - Process for production of 4,4'-dichlorodiphenyl sulphone - Google Patents
Process for production of 4,4'-dichlorodiphenyl sulphone Download PDFInfo
- Publication number
- GB1572916A GB1572916A GB444377A GB444377A GB1572916A GB 1572916 A GB1572916 A GB 1572916A GB 444377 A GB444377 A GB 444377A GB 444377 A GB444377 A GB 444377A GB 1572916 A GB1572916 A GB 1572916A
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- GB
- United Kingdom
- Prior art keywords
- sulfone
- reaction
- monochlorobenzene
- per cent
- product
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
- C07C303/02—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof
- C07C303/22—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof from sulfonic acids, by reactions not involving the formation of sulfo or halosulfonyl groups; from sulfonic halides by reactions not involving the formation of halosulfonyl groups
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
- C07C303/02—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof
- C07C303/04—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof by substitution of hydrogen atoms by sulfo or halosulfonyl groups
- C07C303/06—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof by substitution of hydrogen atoms by sulfo or halosulfonyl groups by reaction with sulfuric acid or sulfur trioxide
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C315/00—Preparation of sulfones; Preparation of sulfoxides
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Description
(54) PROCESS FOR PRODUCTION OF 4,4'-DICHLORODIPHENYL SULFONE
(71) We, UNION CARBIDE CORPORATION, a corporation organized and existing under the laws of the State of New York, United States of America, whose registered Office is, 270 Park Avenue, New York, State of New York, 10017, United States of America, (assignee of ULRICH ALFRED STEINER), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
The invention relates to an improved process for the production of 4,4' -dichlorodiphenyl sulfone.
4,4' -dichlorodiphenyl sulfone is a valuable article of commerce that is used, for instance, as a monomer in the production of polysulfone resins. A commercially important method for its production is described in Keogh et al., U.S. Patent No. 3,701,806. The overall reaction sequence of Keogh et al. is the following:
+ + sock, + S03 30 C Cl monochloro - Thionyl Sulfur benzene Chloride Trioxide "MCB" s-o-socr cr' Hwthetical (2) [IntermedlateJ CIO SQ+Cl );,)ȯc{ SQfHClt p-chlorobenzene diphenyl sulfone suffonyl chloride DCDPS' .PC6SC" (The hypothetical intermediate is not disclosed in Keogh et al., nor to applicant's knowledge, in any other printed publication).
(3) The product mixture of Step (2) is transferred to another reactor, wherein the following reaction occurs:
In common with other methods for the production of 4,4' -dichlorodiphenyl sulfone, side reactions occur in the above-described reaction sequence which reduce the efficiency. It has been discovered that the most prominent source of side reactions stems from the interaction of thionyl chloride and sulfur trioxide to form pyrosulfuryl chloride, a chlorinating agent.
The pyrosulfuryl chloride reacts with various materials in the reaction mixture to form polychlorinated compounds. It has further been discovered that a second side reaction is the reaction of monochlorobenzene with sulfur chloride, S2Cl2 (an impurity in thionyl chloride), to form diphenyl sulfides. Sulfur trioxide is believed to act as the catalyst in this latter reaction. These side reactions are the major cause of the reduction in chemical efficiency of this reaction sequence. The chemical efficiency is about 82 percent, based on SO3. While this is not an impracticably low percentage, it suggests an area wherein significant improvement would be desirable.
From the above findings, it was postulated that an important reason for the loss in chemical efficiency of the process described in Keogh et al. is the simultaneous presence of 803 and
SOCK2 in the reaction mixture. Thus, if their simultaneous presence in the reaction mixture could be eliminated, while at the same time avoiding the introduction of other factors that
adversely affect efficiency, it would seem that 4,4' -dichlorodiphenyl sulfone could be produced significantly more efficiently.
Despite the fact that the process described in Keogh et al leaves room for improvement, it was itself a practical improvement over many of the processes for producing 4,4 -dichlorodiphenyl sulfone that were theretofore available. For instance, a significant commercial advantage over many of the earlier processes was that no isolation of intermediate products was required.
The present invention is based upon the discovery of a novel reaction sequence that can be used to produce 4,4'- dichlorodiphenyl sulfone more efficiently than many of the processes heretofore employed commercially. The process of the invention comprises the steps of:
(a) reacting monochlorobenzene with sulfur trioxide to form p-chlorobenzene sulfonic acid;
(b) reacting the product of step (a) with thionyl chloride in the presence of a catalytic amount of N, N -dimethylformamide ("DMF") at a temperature sufficient to produce p-chlorobenzene sulfonyl chloride; and
(c) reacting the product of step (b) with monochlorobenzene in the presence of a catalytic amount of ferric chloride at a temperature sufficient to produce 4,4' -dichlorodiphenyl sulfone.
The overall chemical reactions that occur in the individual steps of the process are known.
For instance, Wagner and Zook, in "Synthetic Organic Chemistry", John Wiley & Sons, Inc.
(1953), on page 811 point out that sulfur trioxide reacts with aromatic hydrocarbons to produce the corresponding sulfonic acid with some sulfone as a by-product. The reaction of p-chlorobenzenesulfonic acid with thionyl chloride in the presence of at least molar amounts of dimethyl formamide to producep-chlorobenzene -sulfonyl chloride is disclosed in Gregory
U.S. Patent No. 2,888,486. The general reaction of aromatic sulfonic acids with thionyl
chloride in the presence of catalytic amounts of dimethyl formamide to produce the corresponding sulfonyl chloride is disclosed in Bosshard petal., Helvetica Chimica ActaXLII, 1653 (1959), and in Kittila, "Dimethyl Formamide, Chemical Uses", E.I. duPont de Nemours and
Co., Chapter 16, pages 76-77. The overall ferric chloride-catalyzed reaction is described, for instance, in Keogh et al., in Robbins U.S. Patent No. 3,125,064, and in Huismann, U.S.
Patent No. 2,224,964.
While, as indicated above, the overall chemical reactions that occur in each of the steps of the process are known, the combination of these steps results in a process having an unexpectedly high efficiency, compared with the process of Keogh et al, U.S. Patent No.
3,701,806, as will be demonstrated below in the Examples. Further, it is unexpected that, despite the fact that applicant has found that DMF deactivates an equimolar amount of ferric chloride, the DMF need not be removed from the product mixture of step (b) before proceeding to step (c).
In step (a) of the process of the invention, monochlorobenzene is reacted with sulfur trioxide to form p-chlorobenzene sulfonic acid. The overall reaction is the following:
Some 4,4' -dichlorodiphenyl sulfone and sulfuric acid (H2S04) in equimolar amounts are also formed during this reaction.
It is preferred to employ excess MCB in step (a) as a reaction medium. Convenient proportions are found within the range of from 2 to 3 moles of MCB per mole of Soys. It is usual to employ the 803 in the cyclic trimmer form that is known as "Sulfan".
About 8 to 12 per cent of the S03 is converted to sulfone in step (a), an equal amount to sulfuric acid, with the remainder being converted to the sulfonic acid.
The reaction of step (a) is rapid, exothermic, and essentially quantitative. While the temperature of the reaction is not critical, (for instance, the operative temperature range may be as broad as from about -20" to + 2000 C.) it is preferred that the reaction mixture be maintained at a moderate temperature, for example from 30"C. to 700 C., during the course of the reaction. The temperature can be maintained by the usual means, such as heat exchange means on the reactor, and by controlling the rate of addition of S03 to the MCB.
(The heat of reaction is 70,000 BTU/pound-mole or 875 BTU/pound of S03). Moderate initial temperatures in step (b) are desired so that gas evolution in step (b) will not be so rapid that the alkaline scrubbers for the off-gases (SO2 and HCl) are overloaded. Therefore, it is usually desired to maintain the temperature low in step (a) so that it will not be necessary to expend a great deal of time and energy in cooling the reaction mixture prior to step (b).
It is convenient to use atmospheric pressure in step (a), although other pressures may be used. It is desirable to use an inert atmosphere (e.g., nitrogen), for safety reasons, to blanket the reaction mixture throughout the process.
In step (b), the entire reaction product mixture of step (a) is reacted with thionyl chloride in the presence of catalytic amounts of DMF. The following are the principal reactions that occur in step (b):
A slight molar excess of SOC12 is preferred in step (b) because the off-gases will remove
some of the SOCl2 from the reaction mixture by entrainment. Any free sulfonic acid that
remains will deactivate the ferric chloride catalyst in step (c). The stoichiometric amount of SOCIO is 1 mole of SOCl2 per mole of S03 used in the first step. A minimum of about 10 to 20 per cent excess over the stoichiometric amount is preferably used. An excess of about 35 per
cent over stoichiometric has been found to be convenient.
The chemical efficiency of the process will be improved by using very pure SOC12 contain
ing as small a proportion of sulfur chlorides as practical. A proportion of sulfur chlorides in
the SOCK2 of less than 0.5 weight per cent is recommended.
The DMF is employed in step (b) in small, catalytically effective amounts. It is preferred to
employ the DMF in the smallest amount that is catalytically effective so that it will not be
necessary to either remove it prior to step (c), or to use correspondingly more ferric chloride
in step (c). When SOCl2 containing less than about 0.5 weight per cent sulfur chlorides is
used, the minimum catalytically effective amount of DMF is about two mole per cent, based
on moles of S03 charged to step (a). When the SOCl2 contains more sulfur chlorides than the
recommended maximum less DMF may be used (the exact amount needed can be deter
mined by routine exPerimentation) because the sulfur chlorides also catalyze the reactions that occur in step dub). However, since the sulfur chlorides also catalyze undesired side reactions, the chemical efficiency of the process is significantly reduced when the SOY12 contains more sulfur chlorides than the recommended maximum proportion.
Step (b) can be carried out by adding the DMF and thionyl chloride to the product of step (a) at a moderate temperature, e.g., about 30"C., and then heating the reaction mixture at a gradual rate to about 155"C., at which temperature unreacted thionyl chloride will distill from the reaction mixture. The rate of heating will usually be dictated by the ability of the scrubbers to absorb the off-gases, SO2 and HCl. Completion of the reaction can be detected by the termination of off-gas evolution. Typical reaction times for step (b) are from about 4 to 6 hours.
It is desirable to maintain a pressure of from about 1.1 to 1.2 atmospheres on the reaction mixture in step (b) in order to provide a driving force to push the off-gases through the scrubber. Otherwise, the selection of pressure is not at all critical.
For steps (a) and (b), a standard glass-lined reactor with corrosion resistant auxiliary means may be used. In commercial scale operations, it is desirable to use a separate reactor for step (c) in order to avoid contamination of the reaction mixtures of steps (a) and (b) with ferric chloride.
The predominant reaction that takes place in step (c) is the following:
The reaction product of step (b) is charged to the reaction vessel, along with catalytic
quantities of ferric chloride. The quantity of ferric chloride used may, for example, be a
minimum of about 3 to 4 mole per cent, based on S03, more than the moles of DMF charged
to step (b), i.e. [FeC13] may, for example, be a minimum of [DMF] + (0.03 to 0.04) [S03]
where [j is the concentration in moles. There is no advantage in using more.
In one embodiment of the present invention the ferric chloride is employed in an amount
not greater than 6 mole per cent, based on moles of sulfur trioxide employed in step (a).
Additional MCB is also added to flush out the lines, and with the ferric chloride (which is
added as a slurry in MCB). MCB may also be added from time to time during the course to
step (c) in order to maintain the desired temperature by refluxing. The total amount of MCB
added will usually be enough to provide a concentration of about 65 to 70 weight per cent of
sulfone product in MCB. Usually, a total of approximately one additional mole of MCB, per
mole of SO3 charged to step (a), will be added during the course of step (c).
A relatively narrow temperature range (150 C-160 C.) is suggested for step (c) as a
compromise between too slow areaction rate and color body formation. At about 155 "C., the reaction of step (c) takes about 12 hours. The progress of the reaction can be followed by
titrating the off-gas (convenient for lab scale), or by analyzing the reaction mixture by gas
chromatograph for residual sulfonyl chloride content.
A pressure of about 1.1 to 1.2 atmospheres is convenient to employ in step (c). Corrosion
resistant equipment should be employed.
At the completion of the reaction, additional MCB is added to dilute the sulfone to a
concentration of about 40 weight per cent, based on total solution weight (this is done to
maintain the sulfone in solution during cooling and washing), the reaction mixture is then
cooled to about 70 C., washed with water to remove ferric chloride, and the 4,4'
-dichlorodiphenyl sulfone product is recovered by standard means, as by crystallization from
MCB.
the present invention will now be further described by way of the following Example:
EXAMPLE
Step (a)
Two hundred and eighty grams (2.49 moles) of monochlorobenzene are charged to a 1/2 -liter glass reactor equipped with thermometer, dropping funnel, stirrer, and reflux condenser. Sulfur trioxide (sulfan), 93.4 grams (1.17 mole), is added at a constant rate over a period of about 60 minutes. During this period, the temperature is maintained by cooling at about 30 to 40"C.
Step (b)
N,N -dimethylformamide (1.70 grams; 0.023 mole) and thionyl chloride (185 grams; 1.55 moles), are added to the reaction product of step (a) at a temperature of about 30"C. in the same reaction vessel used in step (a). The reflux condenser is attached at the top to an alkaline scrubber. Off-gas evolution begins immediately. The off-gas is absorbed in the scrubber in an aqueous sodium hydroxide solution of known titer. The progress of the reaction is followed by an incremental addition of sodium hydroxide to the solution, and measuring the pH of the solution.
The reaction mixture is heated by a heating mantle, using a constant setting on the "Variac" control. The reaction mixture is heated at a substantially constant rate to a temperature of 1550C. over a period of 4 hours, after which time evolution of off-gas ceased and excess thionyl chloride is distilled.
Step (c)
To the reaction mixture product of step (b), 9.9 grams (0.06 mole) of ferric chloride are added at a temperature of 135"C. The mixture is heated to reflux at 155"C. Periodically, additional monochlorobenzene is added to maintain the reflux at 1550C. The reaction is followed by off-gas measurement, as in step (b). After a period of 12 hours, evolution of off-gas ceases. The reaction mixture is diluted with MCB to a 40 per cent concentration of sulfone, cooled to 70 C., washed with water to remove ferric chloride, and dichlorodiphenyl sulfone is recovered by distilling off MCB. A total of 310.2 grams (1.08 moles) of sulfone are produced as a residue product, 89.5 per cent of which is the desired 4,4' -isomer.
The overall efficiency of the process is the product of the chemical, isomer, recovery, and mechanical efficiencies. The chemical efficiency is a measure of the total sulfone produced, and the isomer efficiency is a measure of the proportion of that sulfone that is the desired 4,4' -isomer. These efficiencies are determined by conventional analytical procedures. The recovery efficiency reflects the amount of sulfone lost in the mother liquor in the crystallization step. It is determined by analysis of the mother liquor, and is a function of the solubility characteristics of the sulfone in MCB (or in any other solvent that might be used). Mechanical efficiency is a measure of the losses caused by handling, and would undoubtedly differ from one apparatus to another. The figure is estimated from a knowledge of the overall efficiency and the determined values for the other three efficiencies.
Typical efficiencies for this process, compared with typical efficiencies of the Keogh et al.
process, are as follows:
Invention Keogh et al.
Chemical 92 82
Isomer 89.5 92.5
Recovery 94.4 92
Mechanical 97.5 97.5
Overall 77 68
WHAT WE CLAIM IS:
1. A process for producing 4,4' -dichlorodiphenyl sulfone comprising the steps of:
a) reacting monochlorobenzene with sulfur trioxide to form p-chlorobenzene sulfonic acid;
b) reacting the product of step a) with thionyl chloride in the presence of a catalytic amount of N,N-dimethylformamide at a temperature sufficient to form p -chlorobenzene sulfonyl chloride; and
c) reacting the product of step b) with monochlorobenzene in the presence of a catalytic amount of ferric chloride at a temperature sufficient to produce 4,4' -dichlorodiphenyl sulfone.
2. A process as claimed in claim 1 wherein the process is carried out in an excess of monochlorobenzene as a reaction medium, and wherein a stoichiometric excess of thionyl chloride is employed.
3. A process as claimed in claim 1 or claim 2 wherein the monochlorobenzene is used, in step (a), in an amount of 2 to 3 moles per mole of sulfur trioxide.
4. A process as claimed in any of claims 1 to 3, wherein the thionyl chloride contains less than 0.5 weight per cent of sulfur chlorides.
5. A process as claimed in claim 4 wherein the N,N-dimethylformamide is employed in an amount not greater than two mole per cent, based on moles of sulfur trioxide employed in step a).
6. A process as claimed in claim 5 wherein the ferric chloride is employed in an amount not greater than six mole per cent, based on moles of sulfur trioxide employed in step a).
7. A process as claimed in any one of claims 1 to 6 wherein the reaction mixture, during step a), is maintained at a temperature from 30"C to 70"C.
8. A process for producing 4,4' -dichlorodiphenyl sulfone as claimed in claim 1 substantially as hereinbefore described with reference to the Example.
9. 4,4' -dichlorodiphenyl sulfone whenever produced by a process as claimed in any one of claims 1 to 8.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (9)
1. A process for producing 4,4' -dichlorodiphenyl sulfone comprising the steps of:
a) reacting monochlorobenzene with sulfur trioxide to form p-chlorobenzene sulfonic acid;
b) reacting the product of step a) with thionyl chloride in the presence of a catalytic amount of N,N-dimethylformamide at a temperature sufficient to form p -chlorobenzene sulfonyl chloride; and
c) reacting the product of step b) with monochlorobenzene in the presence of a catalytic amount of ferric chloride at a temperature sufficient to produce 4,4' -dichlorodiphenyl sulfone.
2. A process as claimed in claim 1 wherein the process is carried out in an excess of monochlorobenzene as a reaction medium, and wherein a stoichiometric excess of thionyl chloride is employed.
3. A process as claimed in claim 1 or claim 2 wherein the monochlorobenzene is used, in step (a), in an amount of 2 to 3 moles per mole of sulfur trioxide.
4. A process as claimed in any of claims 1 to 3, wherein the thionyl chloride contains less than 0.5 weight per cent of sulfur chlorides.
5. A process as claimed in claim 4 wherein the N,N-dimethylformamide is employed in an amount not greater than two mole per cent, based on moles of sulfur trioxide employed in step a).
6. A process as claimed in claim 5 wherein the ferric chloride is employed in an amount not greater than six mole per cent, based on moles of sulfur trioxide employed in step a).
7. A process as claimed in any one of claims 1 to 6 wherein the reaction mixture, during step a), is maintained at a temperature from 30"C to 70"C.
8. A process for producing 4,4' -dichlorodiphenyl sulfone as claimed in claim 1 substantially as hereinbefore described with reference to the Example.
9. 4,4' -dichlorodiphenyl sulfone whenever produced by a process as claimed in any one of claims 1 to 8.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US65720976A | 1976-02-11 | 1976-02-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1572916A true GB1572916A (en) | 1980-08-06 |
Family
ID=24636264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB444377A Expired GB1572916A (en) | 1976-02-11 | 1977-02-03 | Process for production of 4,4'-dichlorodiphenyl sulphone |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS52113942A (en) |
| DE (1) | DE2704972C2 (en) |
| FR (1) | FR2340929A1 (en) |
| GB (1) | GB1572916A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4871876A (en) * | 1987-02-17 | 1989-10-03 | Dresser Industries, Inc. | Preparation of 4,4' dichlorodiphenyl sulfone |
| US4873372A (en) * | 1987-02-17 | 1989-10-10 | Basf Aktiengesellschaft | Isolation of 4,4'-dichlorodiphenyl sulfone |
| US4937387A (en) * | 1986-09-05 | 1990-06-26 | Amoco Corporation | Processes for preparing diaryl sulfones |
| US4983773A (en) * | 1988-10-19 | 1991-01-08 | Basf Aktiengesellschaft | Preparation of bis-(4-chlorophenyl) sulfone |
| EP3441393A1 (en) | 2017-08-07 | 2019-02-13 | Rhodia Operations | New cycloadduct precursors of dihalodiphenylsulfones and preparations thereof |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0062736B2 (en) * | 1979-06-15 | 1992-04-15 | Amoco Corporation | Process for preparing 4-4'-dichlorodiphenyl sulphone |
| EP0020800B1 (en) * | 1979-06-15 | 1983-03-09 | Union Carbide Corporation | Improved process for preparing a mixture of aromatic sulfones and aromatic sulfonyl chlorides |
| JPS56131561A (en) * | 1980-03-03 | 1981-10-15 | Konishi Kagaku Kogyo Kk | Preparation of 4,4'-dichlorodiphenylsulfone |
| JPS6080683U (en) * | 1983-11-10 | 1985-06-04 | 矢崎総業株式会社 | Diode connector with fuse |
| JPS62183379U (en) * | 1986-05-12 | 1987-11-20 | ||
| JPH0418228Y2 (en) * | 1987-04-22 | 1992-04-23 | ||
| US4990678A (en) * | 1989-12-08 | 1991-02-05 | Phillips Petroleum Company | Purification of halogenated aromatic sulfones or ketones |
| GB0921069D0 (en) | 2009-12-01 | 2010-01-13 | Bandodkar Hemant R | Process for the production of a sulfone polymer |
| CN104114519A (en) * | 2011-12-15 | 2014-10-22 | 索尔维特殊聚合物美国有限责任公司 | A process for manufacturing haloaryl compounds from mixtures of isomers of dihalodiarylsulfones |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2224964A (en) * | 1938-07-23 | 1940-12-17 | Gen Aniline & Film Corp | Manufacture of aromatic sulphones |
| US3334146A (en) * | 1964-08-19 | 1967-08-01 | Stauffer Chemical Co | Method for the purification of bis(4-chlorophenyl) sulfone |
| US3701806A (en) * | 1966-06-10 | 1972-10-31 | Union Carbide Corp | Process for preparing a mixture of aromatic sulfones and aromatic sulfonyl chlorides |
| FR1523808A (en) * | 1966-06-10 | 1968-05-03 | Union Carbide Corp | Process for the preparation of a mixture of sulfones and aromatic sulfonyl chlorides, free from aromatic sulfonic acids and their corresponding anhydrides |
| US3673259A (en) * | 1968-10-07 | 1972-06-27 | Chris Craft Ind Inc | Production of aromatic sulfones |
| GB1393929A (en) * | 1972-10-16 | 1975-05-14 | Ici Ltd | Production of di-4-chlorophenyl sulphone |
| GB1351453A (en) * | 1970-02-06 | 1974-05-01 | Ici Ltd | Preparation of 4,4-dichlorodiphenyl sulphone |
| EP0062736B2 (en) * | 1979-06-15 | 1992-04-15 | Amoco Corporation | Process for preparing 4-4'-dichlorodiphenyl sulphone |
-
1977
- 1977-02-03 GB GB444377A patent/GB1572916A/en not_active Expired
- 1977-02-04 JP JP1083877A patent/JPS52113942A/en active Granted
- 1977-02-07 DE DE19772704972 patent/DE2704972C2/en not_active Expired
- 1977-02-10 FR FR7703806A patent/FR2340929A1/en active Granted
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4937387A (en) * | 1986-09-05 | 1990-06-26 | Amoco Corporation | Processes for preparing diaryl sulfones |
| US4871876A (en) * | 1987-02-17 | 1989-10-03 | Dresser Industries, Inc. | Preparation of 4,4' dichlorodiphenyl sulfone |
| US4873372A (en) * | 1987-02-17 | 1989-10-10 | Basf Aktiengesellschaft | Isolation of 4,4'-dichlorodiphenyl sulfone |
| US4983773A (en) * | 1988-10-19 | 1991-01-08 | Basf Aktiengesellschaft | Preparation of bis-(4-chlorophenyl) sulfone |
| EP3441393A1 (en) | 2017-08-07 | 2019-02-13 | Rhodia Operations | New cycloadduct precursors of dihalodiphenylsulfones and preparations thereof |
| WO2019030184A1 (en) | 2017-08-07 | 2019-02-14 | Rhodia Operations | New cycloadduct precursors of dihalodiphenylsulfones and preparations thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2340929A1 (en) | 1977-09-09 |
| JPS52113942A (en) | 1977-09-24 |
| JPS565386B2 (en) | 1981-02-04 |
| FR2340929B1 (en) | 1983-01-14 |
| DE2704972C2 (en) | 1985-08-22 |
| DE2704972A1 (en) | 1977-08-18 |
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| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PE20 | Patent expired after termination of 20 years |
Effective date: 19970202 |