Bayer Aktiengesellschaft

Lanxess Deutschland Gmbh

Gunter Rauchschwalbe

Helmut Fiege

Bernhard Beitzke

Dietmar Mayer

Karl Mannes

Heinz U Blank

Paul Wagner

Horst Behre

Ulrich Notheis

Heinz-Ulrich Blank

Wolfgang Eymann

Christiane Oppenheimer-Stix

Wolfgang Scheinert

Michael Friederich

Hans-Dieter Gerriets

Volkmar Handschuh

Carsten Hummelt

A process is provided for preparing new mixtures of N,N-bis(2-hydroxyalkyl)-4-toluidine derivatives which can be used as polymerization accelerators.

Specific mixtures of N,N-bis(2-hydroxyalkyl)-4-toluidine derivatives, their preparation and a method of using such specific mixtures

The present invention relates to a method for isolating ditrimethylol propane from secondary trimethylol propane production streams.

Method for isolating di-trimethylol propane

Particularly pure di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalates are obtained in good yield and in a simple process by dissolving 5-nitro-isophthalic acid in a mixture of a C.sub.1 -C.sub.4 -alkyl alcohol and a solvent which is miscible or only partially miscible with water, heating in the presence of a strong acid, thus forming a second, aqueous phase, crystallizing out, after the esterification reaction has ended, the di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalate formed from the organic phase by cooling and removing the aqueous phase before or after the di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalate is separated off.

Process for preparing di-C.sub.1 - C.sub.4 -alkyl 5-nitro-isophthalates

4-Hydroxybiphenyl is obtained in non-thixotropic form if a reaction mixture which is obtained by alkaline hydrolysis of biphenyl-4-sulfonic acid and contains 4-hydroxybiphenyl is heated at elevated pressure at above 115.degree. C. and at a pH from 0 to below 6.5.

Process for the preparation of 4-hydroxybiphenyl

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

Crude 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)propane (=tetramethyl-bisphenol A=TMBPA) can be purified by recrystallization, if C.sub.1 -C.sub.4 -monoalcohols with a water content of 2 to 40% by weight relative to the total weight of alcohol and water are used in an amount of 70 to 250% by weight, relative to the amount of TMBPA and the recrystallization is carried out at a temperature of 65.degree. to 150.degree. C.

Process for the purification of crude

In a process for the preparation of an aromatic chloroformic acid ester by contacting a phenol and phosgene, the improvement wherein the reaction is carried out in a homogeneous liquid phase at a temperature of 60.degree. to 180.degree. C. in the presence of organic phosphorus compound of the formula

Process for the preparation of chloroformic acid aryl esters

In a process for the preparation of a naphthalenesulphonyl chloride by reacting an alkali metal salt or ammonium salt of a naphthalenesulphonic acid with thionyl chloride in the presence of a catalytically active substance the improvement wherein the reaction is carried out in the presence of an optionally substituted pyridine, tertiary aliphatic amine, secondary amidine and/or quaternary ammonium salt.

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Leverkusen, Germany

Gunter Rauchschwalbe