Bayer Aktiengesellschaft

Bayer Chemicals Ag

G&uuml;nter Rauchschwalbe

Alexander Klausener

Friedrich Jonas

Knud Reuter

Stephan Kirchmeyer

Karsten Von Dem Bruch

Herbert Emde

Wolfram Kissener

Josef Bremen

Adolf Winkler

Bernd Griehsel

Andreas Sattler

Ralf-Ingo Schenkel

The invention relates to substituted or unsubstituted benzodioxinothiophenes, their preparation and their use for preparing electrically conductive oligomers or polymers, also oligomers or polymers comprising these thiophene derivatives as repeating unit.

Benzodioxinothiophenes, their preparation and use

Described herein is a process for the preparation of 3,4-diaminobenzenesulphonic acid, characterized in that 1,2-diaminobenzene is reacted with anhydrous sulphuric acid which optionally comprises SO in up to stoichiometric amount, at a temperature in the range from 100 to 160&deg; C. with stirring for a reaction time of from 1 to 20 hours; water or ice is added to the reaction mixture, optionally with cooling, up to a sulphuric acid concentration in the range from 30 to 75% by weight, based on the total mixture; the 3,4-diaminobenzenesulphonic acid precipitated out of the reaction mixture is filtered off, optionally washed with dilute sulphuric acid and worked up.

Process for the preparation of isolated 3,4-diaminobenzenesulphonic acid

The invention relates to a process for the alkylation of 3,4-dihydroxythiophene-2,5-dicarboxylic esters or their alkali metal or alkaline earth metal salts with alkylating agents in a polar diluent in the presence of quaternary onium salts.

Process for the alkylation of 3,4-dihydroxythiophene-2,5-dicarboxylic esters

Method for the production of 2,6-dichloro-5-fluoro-nicotinic acid and coarse and particularly pure 2,6-dichloro-5-fluoro-nicotinic acid

As a result of a special precipitation, it is possible to work up reaction mixtures containing 5-aminomethyl-2-chlorothiazole and bis(2-chlorothiazolyl-5-methyl)amine in an advantageous manner and to isolate bis(2-chlorothiazolyl-5-methyl)amine or its salts.

Bis(2-chlorothiazolyl-5-methyl)amine and its salts, and process for working up reaction mixtures comprising 5-aminomethyl-2-chlorothiazole and bis(2-chlorothiazolyl-5-methyl)amine

A process for the preparation of dialkoxythiophenes and alkylene-dioxythiophenes in high purity and very good yields by decarboxylation of dialkoxythiophene-dicarboxylic acids or alkylenedioxythiophenedicarboxylic acids, respectively, in solvents that have a higher boiling point than the product and contain no nitrogen bases.

Process for the preparation of dialkylthiophenes and alkylenedioxythiophenes

Growing community of inventors

Leverkusen, Germany

Günter Rauchschwalbe

Growing community of inventors

Leverkusen, Germany

G&uuml;nter Rauchschwalbe

Günter Rauchschwalbe