Bayer Aktiengesellschaft

Nikolaus Muller

Achim Harder

Winfried Joentgen

Torsten Groth

Peter Andrews

Gerhard Bonse

Lutz Heuer

Guido Steffan

Thomas Essert

Paul Wagner

Werner Lindner

Helmut Kraus

Gerhard Marzolph

Klaus-Peter Heise

Wilhelm Stendel

Norbert Lui

Martin Kugler

Werner Hallenbach

Hans-Joachim Traenckner

Hermann Uhr

Horst Behre

Harro Traubel

Ulrich Liesenfelder

Eckart Kranz

Jurgen Reiners

Heinz-Jurgen Bertram

Erich Wolters

Wolfgang Kiel

Hans-Georg Pirkl

Heinz-Joachim Rother

Heinz-Ulrich Blank

Thomas Menzel

Klaus-Christian Paetz

Bernhard Beitzke

Peter Schnegg

Gerd Schmitz

Andreas Sattler

Ingo Janisch

Hans W Linden

Robert Steffens

Andreas Groschl

Wilfried Kohler

Manfred Schnee

Ute Wollborn

Karl-Hermann Brucher

Joachim-Reinhard Wesener

Johannes Kanellakopoulos

Heinz U Blnak

Process for producing 2-fluorine-1-cyclopropane carboxylic acid

Nitropyrazole amides of the formula (I) ##STR1## are prepared by reacting nitropyrazole esters of the formula (II) ##STR2## with ammonia.

Process for the preparation of a nitropyrazole amide

1-alkyl-pyrazole-5-carboxylic acid esters are prepared by reacting the enolate of a 2,4-diketocarboxylic acid ester with an N-alkylhydrazinium salt in the presence of a solvent. This process allows a particularly economic preparation of 1-alkyl-pyrazole-5-carboxylic acid esters in a simple manner and with only little formation of undesirable isomers.

Process for the preparation of 1-alkyl-pyrazole-5-carboxylic acid esters

Quinazoline-2,4-diones are obtained in high yields and purities by reacting anthranilic acids with isocyanates and then, without isolation of the urea formed as intermediate, treating the reaction mixture with acid.

Process for the preparation of quinazoline-2,4-diones

Nitropyrazole esters of the formula ##STR1## in which R.sup.1 represents C.sub.1 -C.sub.6 -alkyl, are prepared by nitration of the corresponding pyrazole esters. The nitropyrazole esters permit the preparation of a known nitropyrazole amide in a particularly simple and economical manner and thereby improve the preparation of active compounds which are accessible from the nitropyrazole amide.

Process for the preparation of nitropyrazole esters

Use of polyaspartic acid amides as leather auxiliary products

Arylidene-substituted alkylcycloalkanones are prepared from alkyl-substituted cycloalkanones by reaction with aromatic carbonyl compounds in the presence of a basic catalyst and water.

Process for the preparation of arylidene-substituted alkylcycloalkanones

Polyaspartic acid is prepared by polymerization of aspartic acid, maleic acid anhydride, maleic acid or fumaric acid in a solvent at from 130.degree. C. to 300.degree. C., optionally in the presence of ammonia.

Process for preparing polyaspartic acid

The novel compound (2,3-dihydro-5-benzofuranyl)-acetonitrile is prepared by chloromethylating 2,3-dihydro-benzofuran and reacting the resulting 2,3-dihydro-5-chloromethyl-benzofuran with a cyanide. (2,3-Dihydro-5-benzofuranyl)-acetonitrile can be converted by saponification to (2,3-dihydro-5-benzofuranyl)-acetic acid, an important intermediate for the manufacture of various pharmaceutical active substances. This intermediate has hitherto been obtainable only by a laborious procedure and in low yields.

(2,3-dihydro-5-benzofuranyl)-acetonitrile

The polymers according to the invention with repeating succinyl units additionally contain iminodisuccinate units.

Iminodisuccinate-containing polymers

2-Substituted cyclopentanones are prepared by reacting adipic ester with an alkoxide in the presence of an inert solvent, thus obtaining a salt of the cyclopentanone-2-carboxylic ester, alkylating this without isolation, thus obtaining a 2-alkyl-cyclopentanone-2-carboxylic ester and, without isolation, hydrolysing and decarboxylating this by treatment with an acid and heating.

Process for the preparation of 2-substituted cyclopentanones

A particularly advantageous process for the preparation of 2,2-dialkyl-arylidene-cycloalkanones is characterized in that 2-alkyl-arylidene-cycloalkanones are reacted with alkyl halides in the presence of metal hydroxides and tertiary alcohols.

Process for the preparation of 2,2 dialkyl-arylidene-cycloalkanones

A process has been found for the preparation of dialkyl maleates from maleic acid, maleic anhydride or monoalkyl maleates with C.sub.1 -C.sub.8 -alcohols, in particular ethanol, in the presence or absence of an acidic catalyst and at boiling heat, which is characterized in that the escaping water/alcohol/vapour mixture, together with its condensed phase if appropriate, is conducted as feed along a hydrophilic membrane at which it is purged of water and the dehydrated alcohol is returned to the reaction mixture.

Process for the preparation of dialkyl maleates

Polyaspartic acid is prepared by reacting maleic anhydride and ammonia to give maleamic acid, polymerizing the maleamic acid and subsequently hydrolyzing the product to give polyaspartic acid or a salt thereof.

Process for the preparation of polysuccinimide, polyaspartic acid and

Aminomethylene compounds of the formula ##STR1## may advantageously be prepared by reacting C--H-acidic compounds of the formula ##STR2## with formamide acetals of the formula ##STR3## in which the radicals R.sup.1 to R.sup.6 have the meaning given in the description, if the process is carried out in the presence of a secondary amine of the formula ##STR4## in which R.sup.7 and R.sup.8 have the meaning given in the description.

Process for the preparation of aminomethylene compounds

Growing community of inventors

Monheim, Germany

Nikolaus Muller