GB2235923A - Preparation of arylalkylsulfones - Google Patents
Preparation of arylalkylsulfones Download PDFInfo
- Publication number
- GB2235923A GB2235923A GB9019911A GB9019911A GB2235923A GB 2235923 A GB2235923 A GB 2235923A GB 9019911 A GB9019911 A GB 9019911A GB 9019911 A GB9019911 A GB 9019911A GB 2235923 A GB2235923 A GB 2235923A
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- Prior art keywords
- acid
- alkyl
- process according
- hydrogen
- reaction
- 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.)
- Granted
Links
- 238000002360 preparation method Methods 0.000 title claims description 7
- 239000002253 acid Substances 0.000 claims abstract description 18
- 150000003977 halocarboxylic acids Chemical class 0.000 claims abstract description 16
- 239000003054 catalyst Substances 0.000 claims abstract description 10
- 150000003839 salts Chemical class 0.000 claims abstract description 8
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 6
- 230000000911 decarboxylating effect Effects 0.000 claims abstract description 6
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 29
- NLKNQRATVPKPDG-UHFFFAOYSA-M potassium iodide Chemical compound [K+].[I-] NLKNQRATVPKPDG-UHFFFAOYSA-M 0.000 claims description 18
- 238000006243 chemical reaction Methods 0.000 claims description 11
- 125000000217 alkyl group Chemical group 0.000 claims description 10
- 230000015572 biosynthetic process Effects 0.000 claims description 8
- 239000000975 dye Substances 0.000 claims description 8
- 229910052739 hydrogen Inorganic materials 0.000 claims description 8
- 239000001257 hydrogen Substances 0.000 claims description 8
- 238000003786 synthesis reaction Methods 0.000 claims description 7
- FWEVVZQDRPWAND-UHFFFAOYSA-N (2,6-dichloropyridin-3-yl)methanol Chemical compound OCC1=CC=C(Cl)N=C1Cl FWEVVZQDRPWAND-UHFFFAOYSA-N 0.000 claims description 6
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims description 6
- 239000007864 aqueous solution Substances 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 5
- -1 nitro, hydroxy Chemical group 0.000 claims description 5
- 125000004432 carbon atom Chemical group C* 0.000 claims description 4
- 238000006114 decarboxylation reaction Methods 0.000 claims description 4
- MONMFXREYOKQTI-UHFFFAOYSA-N 2-bromopropanoic acid Chemical compound CC(Br)C(O)=O MONMFXREYOKQTI-UHFFFAOYSA-N 0.000 claims description 3
- GAWAYYRQGQZKCR-UHFFFAOYSA-N 2-chloropropionic acid Chemical compound CC(Cl)C(O)=O GAWAYYRQGQZKCR-UHFFFAOYSA-N 0.000 claims description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical group [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 2
- 229910052783 alkali metal Inorganic materials 0.000 claims description 2
- 229910001516 alkali metal iodide Inorganic materials 0.000 claims description 2
- 150000001340 alkali metals Chemical class 0.000 claims description 2
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 2
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 2
- 125000003545 alkoxy group Chemical group 0.000 claims description 2
- 125000004429 atom Chemical group 0.000 claims description 2
- 125000001246 bromo group Chemical group Br* 0.000 claims description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims description 2
- 125000001309 chloro group Chemical group Cl* 0.000 claims description 2
- 125000004663 dialkyl amino group Chemical group 0.000 claims description 2
- 229910052736 halogen Inorganic materials 0.000 claims description 2
- 150000002367 halogens Chemical class 0.000 claims description 2
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 claims description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000000047 product Substances 0.000 description 7
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- 239000011541 reaction mixture Substances 0.000 description 6
- 150000007513 acids Chemical class 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 239000001569 carbon dioxide Substances 0.000 description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 150000008050 dialkyl sulfates Chemical class 0.000 description 3
- 239000002243 precursor Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- KBPLFHHGFOOTCA-UHFFFAOYSA-N 1-Octanol Chemical compound CCCCCCCCO KBPLFHHGFOOTCA-UHFFFAOYSA-N 0.000 description 2
- XWUJSAXHQJZQCG-UHFFFAOYSA-N 3-amino-1,3-diazaspiro[4.4]nonane-2,4-dione Chemical compound O=C1N(N)C(=O)NC11CCCC1 XWUJSAXHQJZQCG-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 150000001350 alkyl halides Chemical class 0.000 description 2
- 239000002168 alkylating agent Substances 0.000 description 2
- 229940100198 alkylating agent Drugs 0.000 description 2
- 238000005804 alkylation reaction Methods 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- FOCAUTSVDIKZOP-UHFFFAOYSA-N chloroacetic acid Chemical compound OC(=O)CCl FOCAUTSVDIKZOP-UHFFFAOYSA-N 0.000 description 2
- 229940106681 chloroacetic acid Drugs 0.000 description 2
- 230000008030 elimination Effects 0.000 description 2
- 238000003379 elimination reaction Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000000543 intermediate Substances 0.000 description 2
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- FVAUCKIRQBBSSJ-UHFFFAOYSA-M sodium iodide Inorganic materials [Na+].[I-] FVAUCKIRQBBSSJ-UHFFFAOYSA-M 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- RWIQBTLWENXMRJ-UHFFFAOYSA-N 1-chloro-4-[(4-chloro-3-nitrophenyl)methylsulfonylmethyl]-2-nitrobenzene Chemical compound C1=C(Cl)C([N+](=O)[O-])=CC(CS(=O)(=O)CC=2C=C(C(Cl)=CC=2)[N+]([O-])=O)=C1 RWIQBTLWENXMRJ-UHFFFAOYSA-N 0.000 description 1
- LMCOQDVJBWVNNI-UHFFFAOYSA-N 1-chloro-4-methylsulfonylbenzene Chemical compound CS(=O)(=O)C1=CC=C(Cl)C=C1 LMCOQDVJBWVNNI-UHFFFAOYSA-N 0.000 description 1
- YYDNBUBMBZRNQQ-UHFFFAOYSA-N 1-methyl-4-methylsulfonylbenzene Chemical compound CC1=CC=C(S(C)(=O)=O)C=C1 YYDNBUBMBZRNQQ-UHFFFAOYSA-N 0.000 description 1
- SFLMBHYNCSYPOO-UHFFFAOYSA-N 2-amino-4-methylsulfonylphenol Chemical compound CS(=O)(=O)C1=CC=C(O)C(N)=C1 SFLMBHYNCSYPOO-UHFFFAOYSA-N 0.000 description 1
- AOQYAMDZQAEDLO-UHFFFAOYSA-N 4-chlorobenzenesulfinic acid Chemical compound OS(=O)C1=CC=C(Cl)C=C1 AOQYAMDZQAEDLO-UHFFFAOYSA-N 0.000 description 1
- FXJVNINSOKCNJP-UHFFFAOYSA-N 4-methylbenzenesulfinic acid Chemical compound CC1=CC=C(S(O)=O)C=C1 FXJVNINSOKCNJP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- SJEYSFABYSGQBG-UHFFFAOYSA-M Patent blue Chemical compound [Na+].C1=CC(N(CC)CC)=CC=C1C(C=1C(=CC(=CC=1)S([O-])(=O)=O)S([O-])(=O)=O)=C1C=CC(=[N+](CC)CC)C=C1 SJEYSFABYSGQBG-UHFFFAOYSA-M 0.000 description 1
- 239000000980 acid dye Substances 0.000 description 1
- 230000029936 alkylation Effects 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- 239000007900 aqueous suspension Substances 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000004310 lactic acid Substances 0.000 description 1
- 235000014655 lactic acid Nutrition 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000434 metal complex dye Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 235000009518 sodium iodide Nutrition 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 150000003457 sulfones Chemical class 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C315/00—Preparation of sulfones; Preparation of sulfoxides
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Arylalkylsulfones are obtained in good yield and purity by reacting an arylsulfinic acid or a salt thereof with a halocarboxylic acid or a salt thereof in the presence of a water-soluble iodide as catalyst, and subsequently decarboxylating the reaction product. <IMAGE>
Description
1-17742/=/BSQ Process for the preparation of arvlalkvlsulfones The present
invention relates to a novel process for the preparation of arylalkylsulfones.
A number of processes for the preparation of these intermediates for dye synthesis have already been described, for example the reaction of arylsulfinates with alkyl halides and the alkylation of arylsulfinic acids with dialkyl sulfates or dialkyl alkanephosphonates. The principal shortcomings of these processes, which are particularly evident in production on an industrial scale, are to be found in the formation of ether and alcohol as byproducts of the alkylation reaction, thereby resulting in serious safety problems. Further, the use of dialkyl sulfates as alkylating agents leads to pollution of the wastewater with the environmentally problematical monoalkyl sulfates. Finally, aggressive alkylating agents such as alkyl halides and dialkyl sulfates require the observance of special safety measures. It is taught in US patent 19 39 416 that arylalkylsulfones can be obtained from the corresponding arylsulfonylcarboxylic acids by elimination of carbon dioxide. These arylsulfonylcarboxylic acids can be obtained by reacting arylsulfinates with halocarboxylic acids (q.v. R. Otto, Chem. Ber. 18, 154-162). While this route of synthesis for preparing arylsulfonylcarboxylic acids does not give rise to problems comparable to those described above, it is unsatisfactory as regards the yield and purity of the products.
It is the object of the present invention to provide a technically simple process for the process of arylalkylsulfones, especially one which can be carried out on an industrial scale, which process substantially rules out safety and environmental problems and leads to the desired products in high yield (95 to 100 %, based on the arylsulfinic acid used) and purity (greater than 90 %, based on the product).
This object is achieved in the practice of this invention by carrying out the reaction of arylsulfinates with halocarboxylic acids described in Chem. Ber. 18, 154-162, in the presence of a water-soluble iodide as catalyst and decarboxylating the reaction product.
Accordingly, the present invention relates to a process for the preparation of arylalkylsulfones by reacting an arylsulfinic acid, or a salt thereof, with a halocarboxylic acid, or a 1 salt thereof, in aqueous solution, and subsequently decarboxylating the reaction product so obtained, which process is carried out in the presence of a water-soluble iodide as catalyst.
Further ob ects of the invention are the arylalkylsulfones obtained by the above process, in j particular 4-chlorophenylethylsulfone, and the use of said sulfones as intermediates for the synthesis of dyes, especially acid dyes and metal complex dyes.
In the process of this invention, the aryIsulfinic acid and halocarboxylic acid, or a salt of each, are reacted in aqueous solution. The ratio of arylsulfinic acid to halocarboxylic acid is preferably 1: 1 to L2. In principle, the halocarboxylic acid may be added to an aqueous suspension of the arylsulfinic acid or the arylsulfinic acid may be added to the halocarboxylic acid. The reaction temperature is preferably in the range from 20 to 1001C. Below 2WC the reaction rate may be too slow for the reaction to be carried out economically. In the temperature range above 60 to 1OWC, the hydrolysis of the halocarboxylic acid may reach such proportions that substantial losses in yield of arylalkylsulfone occur. In this event, an excess of halocarboxylic acid can then be used to reduce these losses. The pH is preferably kept in the range from 3 to 7.
The arylsulfonylcarboxylic acid derivative obtained in this reaction is decarboxylated, without isolation, by heating the reaction mixture to a temperature in the range from preferably 80 to 1 100C. The decarboxylation must therefore be carried out under normal pressure or under elevated pressure. During the elimination of carbon dioxide, the pH will preferably be kept at that value to which it was adjusted in the above described reaction of an aryIsulfinic acid with a halocarboxylic acid.
The catalyst used in the process of the invention is a water-soluble iodide, preferably an alkali metal iodide such as sodium or potassium iodide. It is convenient to use 0.01 to 0.05 mol of catalyst per mol. of halocarboxylic acid. The use of such a catalyst in the reaction of an arylsulfinic, acid with a halocarboxylic acid increases the yield as well as the purity of the arylalkylsulfone obtained.
Normally the arylalkylsulfone obtained is precipitated after the decarboxylation as an oil. This oil will usually contain only insignificant amounts of impurities, so that it can mostly be further processed direct to a dye (or dye precursor). The arylalkylsulfones can be obtained in great purity by extraction with an organic solvent, for example toluene, and recrystallisation of the extracted product from a suitable solvent such as ethanol.
1.
The aryIsulfinic: acid used in the process of this invention is preferably a compound of formula RI,, J S02M R2 wherein R, and R2 are each independently of the other hydrogen, alkyl of 1 to 6 carbon atoms, alkoxy of 1 to 6 atoms, halogen, nitro, hydroxy, - C024 wherein Z is hydrogen or alkyl, sulfb, amino, alkyl or dialkylamino or -NHCOY, wherein Y is alkyl, and M is hydrogen, ammonium, an alkaline earth metal or an alkali metal, and the halocarboxylic acid is a compound of formula Rr-TH-COOH X wherein R3 is hydrogen or alkyl of 1 to 4 carbon atoms, and X is chloro or bromo.
The process of this invention is particularly suitable for the preparation of 4-chlorophenylethylsulfone. Accordingly, a preferred embodiment of this process comprises reacting 4-chlorophenyl- I -sulfinic acid with 2-chloroor 2-bromopropionic acid, in aqueous solution at a pH value of 5 to 6 and in the temperature range from 40 to SOT, in the presence of potassium iodide as catalyst, and subsequently decarboxylating the reaction product so obtained in the temperature range from 100 to 1 10T. The 4-chlorophenylethylsulfone obtained as an oil is sufficiently pure for further processing to, for example, 4-chloro-3- nitrophenylethylsulfone, another precursor for the synthesis of dyes.
4-Chlorophenylmethylsulfone can also be readily obtained by the process of this invention. This compound can be converted, for example, into 3amino-4-hydroxyphenylmethylsulfone, which is also an important precursor for dye synthesis.
The process of this invention can be simply carried out in conventional apparatus and, in contradistinction to certain prior art processes, does not require any special safety measures. The by-products formed are mainly only salts such as sodium chloride, and also carbon dioxide and hydroxycarboxylic acid, for example the unproblematical lactic acid in the reaction with 2-halopropionic acid.
The invention is illustrated by the following Examples.
Example 1: 0.2 mol of 4-chlorophenyl-l-sulfinic acid are suspended in 70 mI of water. Then 0.04 mol of potassium iodide and 0.5 g of an antifoam based on octanol are added, and the pH is adjusted to 5.0-5.5. The temperature of the reaction mixture is raised to 45-SOIC and 0.4 mol of 2chloropropionic acid is added dropwise over 3 hours, while keeping the pH at 6 by addition of sodium hydroxide. The reaction mixture is thereafter refluxed for 45 hours. 4-Chlorophenylethylsulfone precipitates from the cooled reaction mixture as a yellowish-brown oil. This product can then be isolated in 95 % yield and 92 % purity. It is sufficiently pure in this form for further processing, for example to 4-chloro-3nitrophenylethylsulfone.
Example 2: The procedure of Example 1 is repeated, using 2-bromopropionic acid in place of 2-chloropropionic acid, to give 95 % of the oily product in 90 % purity.
Example 3: 394 ml of water are put into a 2 mI glass beaker. With stirring, 339.7 g of chloroacetic acid are added over 10 minutes. A clear, colourless solution forms, to which 281.8 g of aqueous sodium hydroxide are added dropwise over 15-20 minutes. With good stirring, 500.0 g of toluene-4-sulfinic acid are added over 10-15 minutes, the temperature rising to ca. 45C Then 4.9 g of potassium iodide are added and the reaction mixture is heated to 75C over 30-60 minutes and from 75'C to reflux (104'C) over 30-60 minutes and refluxed for 40 hours. 4Methylphenylmethylsulfone is obtained as an oil in 93 % yield.
Example 4: 394 mI of water are put into a 2 mI glass beaker. With stirring, 339.7 g of chloroacetic acid are added over ca. 10 minutes. A clear, colourless solution forms, to which 281.8 g of aqueous sodium hydroxide are added dropwise over 15-20 minutes. A temperature of 30C is not exceeded by cooling with ice. The pH is adjusted to 7.0 by the slow addition of ca. 13.3 g of sodium hydrogencarbonate. With good stirring, 565.5 g of 4-chlorobenzene-1-sulfinic acid are added over 10-1 5 minutes. Then 4.9 g of potassium iodide are added and the reaction mixture is heated to 7ST over 30-60 minutes and from 7ST to reflux (104T) over 30-60 minutes, refluxed for 20 hours, and then cooled to 40T over ca. 2 hours, whereupon sugar-like crystals of 4-chlorophenylmethylsuifone t fl precipitate.
The product is sufficiently pure for further processing to, for example, 4-chloro-3-nitrophenylmethylsulfone.
Claims (10)
1. A process for the preparation of arylalkylsulfones by reacting an aryIsulfinic acid, or a salt thereof, with a halocarboxylic acid, or a salt thereof, in aqueous solution, and subsequently decarboxylating the reaction product so obtained, which process is carried out in the presence of a water-soluble iodide as catalyst.
2. A process according to claim 1, wherein the aryIsulfinic acid is a compound of formula R, S02M R2 wherein R, and R2 are each independently of the other hydrogen, alkyl of 1 to 6 carbon atoms, alkoxy of 1 to 6 atoms, halogen, nitro, hydroxy, - CO2Z, wherein Z is hydrogen or alkyl, sulfb, amino, alkyl or dialkylamino or -NHCOY, wherein Y is alkyl, and M is hydrogen, ammonium, an alkaline earth metal or an alkali metal, and the halocarboxylic acid is a compound of formula RS1H-COOH X wherein R3 is hydrogen or alkyl of 1 to 4 carbon atoms, and X is chloro, or bromo.
3. A process according to claim 1, wherein the reaction is carried out in the temperature range from 20 to 1OWC, and the decarboxylation is carried out in the temperature range from 80 to 1 100C.
4. A process according to claim 1, wherein the pH is kept in the range from 3 to 7 during the reaction and decarboxylation.
5. A process according to claim 1, wherein the catalyst is an alkali metal iodide.
6. A process according to any one of claims 1 to 5, which comprises reacting 4-chloro- phenyl- 1 -sulfinic acid with 2-chloro- or 2-bromopropionic acid, in aqueous solution at a pH value of 5 to 6 and in the temperature range from 40 to 50PC, in the presence of potassium iodide as catalyst, and subsequently decarboxylating the reaction product so obtained in the temperature range from 100 to 1 100C.
7. An arylalkylsulfone obtained by the process as claimed in claim 1.
8. 4-Chlorophenylethylsulfone prepared by the process as claimed in claim 6.
9. Use of an arylalkylsulfone as claimed in claim 7 as intermediate for the synthesis of dyes.
10. Use of 4-chlorophenylethylsulfone as claimed in claim 8 as intermediate for the synthesis of dyes.
Publ shed 1991 at The Patent Office. State House. 66171 High Holborn, London WC] R 417. Further copies may be obtained from Multiple Sales Branch. Unit 6. Nine Mile Point Cwmfelinfach. Cross Keys. Newport. NPI 7HZ. Printed by x techniques lid, St LlarY Cray, Rent.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH334989A CH679306A5 (en) | 1989-09-14 | 1989-09-14 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9019911D0 GB9019911D0 (en) | 1990-10-24 |
| GB2235923A true GB2235923A (en) | 1991-03-20 |
| GB2235923B GB2235923B (en) | 1992-12-23 |
Family
ID=4254053
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9019911A Expired - Lifetime GB2235923B (en) | 1989-09-14 | 1990-09-12 | Process for the preparation of arylalkylsulfones |
Country Status (3)
| Country | Link |
|---|---|
| CH (1) | CH679306A5 (en) |
| DE (1) | DE4029131A1 (en) |
| GB (1) | GB2235923B (en) |
-
1989
- 1989-09-14 CH CH334989A patent/CH679306A5/de not_active IP Right Cessation
-
1990
- 1990-09-12 GB GB9019911A patent/GB2235923B/en not_active Expired - Lifetime
- 1990-09-13 DE DE19904029131 patent/DE4029131A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| GB9019911D0 (en) | 1990-10-24 |
| DE4029131A1 (en) | 1991-03-28 |
| CH679306A5 (en) | 1992-01-31 |
| GB2235923B (en) | 1992-12-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19990912 |