Claims
- 1. A process for the preparation of an aromatic (di)chlorosulphonic acid or (di)bromosulphonic acid by reacting an aromatic sulphonic acid with a halogenating agent selected from the group consisting of chlorine and bromine, said chlorine and bromine being in elemental form or in the form of a compound which releases chlorine or bromine under the process conditions, wherein the reaction is carried out without the use of a catalyst and in a melt, consisting essentially of the aromatic sulphonic acid at a temperature of 40.degree.-200.degree. C.,
- wherein the aromatic sulphonic acid reacted is an aromatic sulphonic acid or mixture of aromatic sulphonic acids of the formula ##STR4## in which R.sub.1 denotes hydrogen, straight-chain or branched C.sub.1 -C.sub.20 -alkyl, C.sub.3 -C.sub.8 -cycloalkyl, benzyl, substituted benzyl, phenyl, substituted phenyl, straight-chain or branched C.sub.1 -C.sub.20 -alkoxy, benzyloxy, substituted benzyloxy, phenoxy, substituted phenoxy, nitro or cyano,
- R.sub.2 represents hydrogen, methyl or ethyl and
- R.sub.3 represents hydrogen, methyl, ethyl, fluorine, chlorine or bromine, where furthermore R.sub.1 and R.sub.2 together can denote a fused benzene ring or substituted benzene ring, a fused aromatic or non-aromatic 5- or 6-membered heterocycle, or trimethylene or tetramethylene.
- 2. The process of claim 1, wherein chlorine or bromine in elemental form is employed.
- 3. The process of claim 2, wherein elemental chlorine is employed.
- 4. The process of claim 3, wherein the elemental chlorine is passed in at a pressure of between 1 and 6 bar.
- 5. The process of claim 1, wherein 90-130 mol % of halogenating agent are employed per halogen to be introduced.
- 6. The process of claim 1, wherein the reaction is carried out at 50.degree.-120.degree. C.
- 7. The process of claim 1, wherein the aromatic sulphonic acid reacted is one of the formula ##STR5## in which R.sub.11 denotes hydrogen, straight-chain or branched C.sub.1 -C.sub.20 -alkyl, straight-chain or branched C.sub.1 -C.sub.20 -alkoxy, cyclopropyl, cyclopentyl, cyclohexyl, benzyl, substituted benzyl, phenyl or substituted phenyl,
- R.sub.12 represents hydrogen, methyl or ethyl and
- R.sub.3 has the meaning given in claim 1,
- where furthermore R.sub.11 and R.sub.12 together can denote a fused benzene ring or substituted benzene ring, or trimethylene or tetramethylene.
- 8. The process of claim 7, wherein the aromatic sulphonic acid reacted is one of the formula ##STR6## in which R.sub.21 denotes hydrogen, straight-chain or branched C.sub.1 -C.sub.4 -alkyl and
- R.sub.22 and R.sub.13 independently of one another represent hydrogen, methyl or ethyl.
- 9. The process of claim 1, wherein the aromatic sulphonic acid is employed as sulphonation melt as obtained in the sulphonation of the basic aromatic compound with SO.sub.3.
- 10. The process of claim 7, wherein the aromatic sulphonic acid employed is 4-toluene-sulphonic acid.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3930994 |
Sep 1989 |
DEX |
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Parent Case Info
This application is a continuation of application Ser. No. 577,378, filed Sep. 4, 1990 now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4131619 |
Pews |
Dec 1978 |
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FRX |
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JPX |
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GBX |
Non-Patent Literature Citations (1)
Entry |
Bernhard Prager et al.; "Beilsteins Handbuch Der Organischen Chemie" pp. 56-57; 1928. |
Continuations (1)
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Number |
Date |
Country |
Parent |
577378 |
Sep 1990 |
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