Bayer Aktiengesellschaft

Lanxess Deutschland Gmbh

Siemens-allis, Inc.

Bayer Chemicals Ag

Symrise Ag

Herbert Emde

Heinz U Blank

Wolfram Kissener

Peter Schnegg

Klaus-Christian Paetz

Paul Wagner

Reinhard Langer

Achim Fessenbecker

Bernhard Lehmann

Friedrich Durholz

G&uuml;nter Rauchschwalbe

Dietmar Mayer

Dorde Jovcic

Rolf Schimpf

Manfred Gerlach

Günter Rauchschwalbe

Hartwig Wendt

Roland Busse

Urban Recht

Jurgen Kuprat

The present invention relates to an improved process for preparing cyclopropanecarboxylic acid and alcohols.

Process for hydrolysing cyclopropanecarboxylic esters to the free acid

A process for the preparation of 2-phenylbenzimidazole-5-sulphonic acid, characterized in that 3,4-diaminobenzenesulphonic acid is reacted at a pH between 4 and 7 in aqueous solution with 0.9 to 1.5 mol of benzaldehyde per mole of 3,4-diaminobenzenesulphonic acid and with 1.0 to 3.0 mol of SOper mole of 3,4-diaminobenzenesulphonic acid, or an agent which comprises 1.0 to 3.0 mol of SOper mole of 3.4-diaminobenzenesulphonic acid, is described.

2-phenylbenzimidazole-5-sulphonic acid from isolated 3,4-diaminobenzenesulphonic acid and use thereof in cosmetic preparations

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 present invention relates to cleaning compositions which, as powder or as aqueous formulation, comprise sodium bicarbonate and, as dispersants, polyaspartic acids and/or salts thereof, to the use of these cleaning compositions for the abrasive cleaning of hard surfaces, and also to a method of cleaning surfaces contaminated with deposits using these cleaning compositions.

Use of polyaspartic acids in cleaner formulations with abrasive action

5-Fluoro-2-nitrobenzoic acid having low contents of 3-fluoro-2-nitro-benzoic acid is prepared in a simple manner by nitrating 3-fluorobenzoic acid in an anhydrous medium using an anhydrous nitrating acid and isolating and purifying 5-fluoro-2nitro-benzoic acid, by taking 7.5 to 15 parts by weight of water, based on 1 part by weight of 3-fluorobenzoic acid used, introducing the reaction mixture reacted to exhaustion into this volume of water taken, filtering off the precipitate formed and washing it with water.

Process for the preparation of 5-fluoro-2-nitrobenzoic acid

2- and 3-Nitrobenzaldehydes suitable for use as intermediates for the preparation of pharmaceuticals are obtained in a simple manner and without risk of uncontrolled decompositions by distilling mixtures of nitrobenzaldehyde isomers at bottom temperatures of at most 200.degree. C. in the presence of monomeric and/or polymeric aromatic amines and/or phenols and/or N- and S-containing phenothiazines.

Process for separating mixtures of nitrobenzaldehyde isomers

Aminoaryl-sulphonic acids can be prepared by reaction of arylamines and sulphuric acid at elevated temperature and under pressure, where water formed and, where appropriate, water present as water of dilution, is left in the reaction mixture until the end of the reaction.

Process for the preparation of aminoaryl-sulphonic acids

Reactions of liquid starting substances to give chemical compounds in which these chemical compounds are obtained as solids can be carried out by spraying the liquid starting substances from separate nozzles such that the liquid starting substances are mixed in the spray cones, which penetrate one another, and thereby react.

Process for the preparation of chemical compounds obtained as solids

P-Toluidine-2-sulphonic acid (5-amino-2-methylbenzenesulphonic acid) is obtained in very pure form and virtually free of p-toluidine-3-sulphonic acid (2-amino-5-methylbenzenesulphonic acid) by reacting p-toluidine at 10.degree.-55.degree. C. with oleum in sulphuric acid. The molar ratio of SO.sub.3 to p-toluidine in this reaction is 1-3.0:1. The reaction mixture is worked up by pouring into water and filtering off the precipitated p-toluidine-2-sulphonic acid.

Process for preparing p-toluidine-2-sulphonic acid

Aromatic aminosulphonic acids which have a reduced content of discoloring by-products are obtained when aromatic amines are reacted with a sulphonating agent in a reaction medium at least some of which consists of tetramethylene sulphone.

Process for the preparation of aminoarylsulphonic acids in sulfolene

Aminoarylsulphonic acids which have a relatively high purity and a relatively low content of aminoaryldisulphonic acids can be obtained, if they are prepared, from the corresponding arylammonium hydrogen sulphates, by an improved version of the so-called baking process, wherein the reaction is carried out under pressure at a temperature of at least 140.degree. C. and, at least partially, in the presence of water.

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Kö'ln, Germany

Herbert Emde