Bayer Aktiengesellschaft

Christian Laue

Dieter Arlt

Pieter Ooms

Georg Schroder

Rolf Grosser

Michael Schelhaas

Carl Casser

Ulrich Notheis

Henry Giera

Hans-Josef Buysch

Manfred Jautelat

Dietmar Bielefeldt

Michael Negele

Dieter Habich

Heinrich Konigshofen

Heinz Ziemann

Wolfram Sirges

Ursula Pentling

Reinhard Preuss

Lothar Ruetz

Joachim Haider

Michaela Meiers

Gerhard Arnold Braun

Markus Oberth&uuml;r

This invention relates to covulcanizable anti-aging agents which can be produced by the reaction of p-phenylenediamines, which are optionally substituted, and/or of sterically hindered phenols, with bifunctional alkyl, aryl and/or aralkyl compounds and by subsequent reaction of the products thus obtained with sulfur and/or sulfur donor compounds. The anti-aging agents according to the present invention maintain their efficacy over a long period of time and are distinguished in particular by the fact that in practice, they are hardly extracted from the vulcanized products by water, by oil and/or petrol, or by hydraulic fluids.

Covulcanizable anti-aging agents

Process for preparing 4-aminodiphenylamine

The present invention provides a process for preparing (4-nitroso-phenyl)phenyl-hydroxylamine which is characterized in that nitrobenzene is reacted in the presence of hydroxide and/or oxide-containing bases, optionally in the presence of solvents, at temperatures of 20 to 180.degree. C. and pressures of 0.1 to 10 bar. The process according to the invention has the particular advantage that it uses inexpensive and cost-effective nitrobenzene as starting material instead of the nitrosobenzene conventionally used hitherto.

Process for preparing (4-nitro-sophenyl)phenylhydroxylamine

4-aminodiphenylamines are prepared by hydrogenating nitrosobenzene or mixtures of nitrosobenzene and nitrobenzene with hydrogen in the presence of bases containing hydroxide, oxide and/or alkoxide groups and heterogeneous catalysts in inert aprotic solvents at temperatures of from 0 to 200.degree. C. and at pressures of from 0.1 to 150 bar.

Process for the preparation of 4-aminodiphenylamine

This invention relates to easily conveyable and easily meterable mixtures having high stability in storage, containing aromatic mineral oils and phenylenediamines, the content of phenylenediamines in the mixture being 1 to 99 wt. %. The mixtures of mineral oils and phenylenediamines according to the invention are used in the production of rubbers and rubber articles.

Easily transportable and meterable mixtures of aromatic oils and

4-aminodiphenylamines are produced by hydrogenating nitrobenzene with hydrogen in the presence of bases containing hydroxide and/or oxide groups and heterogeneous catalysts and in the presence of inert aprotic solvents at temperatures of 0 to 200.degree. C. and pressures of 0.1 to 150 bars.

Process for producing 4-aminodiphenylamine

The invention relates to enantiomerically pure bisphosphines of the general formula (I) ##STR1## where R is as defined in the description, a process for their preparation and their use in metal complexes as catalysts for asymmetric reactions, in particular asymmetric hydrogenations.

Bisphosphines as catalysts for asymmetric reactions

The invention relates to novel bisphosphonates and to processes for their preparation and for their resolution into the enantiomers. The bisphosphonates according to the invention are valuable intermediates for the preparation of bisphosphine compounds, especially chiral bisphosphine ligands. These in turn are constituents of transition metal complexes which are used as catalysts inter alia in asymmetric hydrogenation. The novel bisphosphonates have the general formula (I) ##STR1## in which R.sup.1 is linear or branched alkyl having up to 6 carbon atoms, aryl or aralkyl, each of which can optionally be substituted, or two radicals R.sup.1 together are a bridging hydrocarbon radical having up to 6 carbon atoms,

Intermediates for the synthesis of bisphosphine compounds

The invention relates to novel enantiomerically pure bisphosphines of the general formula (I) ##STR1## in which R, R.sup.1 and R.sup.2 have the meanings given in the description, a process for the preparation thereof and the use thereof in metal complexes as catalysts for asymmetric hydrogenations.

Bisphosphines for asymmetric hydrogenation catalysts

The present invention relates to novel 2-arylpropenoic acids, derivatives thereof, processes for their preparation and their use in the preparation of S-ketoprofen.

Intermediates and their use in the preparation of s-ketoprofen

New .alpha.-trifluoromethyl-substituted, saturated bicyclic amines of the formula ##STR1## in which R.sup.1 represents hydrogen, C.sub.1 - to C.sub.8 -alkyl or C.sub.1 - to C.sub.8 -alkoxy,

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Monheim, Germany

Christian Laue