Bayer Aktiengesellschaft

Wolfgang Eymann

Helmut Fiege

Horst Behre

Alexander Klausener

Heinz U Blank

Paul Wagner

Rolf Feller

Ferdinand Hagedorn

Michael Dockner

Heinz-Ulrich Blank

Bernhard Beitzke

Otto Neuner

Gunter Rauchschwalbe

Friedrich-Wilhelm Ullrich

Frank Arndt

Bernd-Michael K&ouml;nig

Frank D&ouml;bert

Uwe Heinz

Herbert Muller

Rudolf Wiemers

Helmut Holzem

This invention relates to a process for preparing N-substituted hydroxylamines from N-substituted aryl- or heteroaryloxaziridines by acid hydrolysis and isolation of the N-substituted hydroxylamines in the form of their salts.

Process for preparing N-substituted hydroxylamines and salts thereof

The present invention relates to a process for preparing trimethylol compounds and formic acid by reaction of formaldehyde and aldehydes in the presence of a nitrogen base and distillation of the resulting reaction mixture in the presence of an auxiliary.

Process for preparing trimethylol compounds and formic acid

The invention relates to novel S-(4-biphenyl)-thiosulfuric acids and their salts, to a method for producing them from S-(4-biphenyl)-thiosulfinic acids and their salts, and to a method for producing 4-mercaptobiphenyls from the S-(4-biphenyl)-thiosulfuric acids and their salts.

S-(4-biphenyl)-thiosulphuric acids and their salts, method for producing the same and method for producing 4-mercaptobiphenyls

N-Phenyl-1-naphthylamine can be prepared by reaction of aniline and 1-naphthylamine in the liquid phase at 100-400.degree. C. under normal pressure, a catalyst mixture comprising boron and fluorine being employed. Such catalyst mixtures can be obtained, for example, by reaction of hydrogen fluoride, boric acid and aniline and/or 1-naphthylamine. The catalyst is recovered and can be employed again. The reaction can be carried out discontinuously or continuously.

Preparation of N-phenyl-1-naphthylamine

Process for preparing 4,6-diamino-resorcinol dihydrochloride

N-arylaminoacrylic acid derivatives are obtained in good yields and in high purities when benzoylacetic acid derivatives are reacted with N-arylimino ethers. The products thus prepared are used, in particular, for the preparation of 4-quinolone-3-carboxylic acid derivatives, which have an outstanding bactericidal action.

Process for the preparation of N-arylaminoacrylic acid derivatives and

4-Fluorothiophenol is obtained in outstanding purifies and yields if 4-fluorobenzenesulphonyl chloride is reacted with sodium hydrogen sulphite solution to give a solution of sodium 4-fluorobenzenesulphinate, this solution is reduced with sulphur dioxide to give 4,4'-difluorodiphenyl disulphide and finally this is reacted with sodium borohydride in a water-miscible inert organic solvent to give 4-fluorothiophenol (sodium salt). Free 4-fluorothiophenol can be isolated from the sodium salt solution by acidification.

Process for the preparation of 4-fluorothiophenol

4,6-diaminoresorcinol can be prepared in a plurality of steps in such a way that a) 1,3-dichlorobenzene is nitrated with a mixed acid of HNO.sub.3, H.sub.2 SO.sub.4 and SO.sub.3 at 0 to 40.degree. C. in anhydrous H.sub.2 SO.sub.4, b) the resulting 1,3-dichloro-4,6/2,4-dinitrobenzene isomeric mixture is first reacted with benzyl alcohol in the presence of a strong base at -15.degree. C. to +15.degree. C. and then at 20.degree. to 40.degree. C. to give the dibenzyloxy compound and c) the 1,3-dibenzyloxy-4,6-dinitrobenzene isomer arising in pure form in b) is converted to the 4,6-diaminoresorcinol by catalytic hydrogenation.

Process for the preparation of 4,6-diaminoresorcinol

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Koln, Germany

Wolfgang Eymann