Degussa Aktiengesellschaft

Asta Medica, Aktiengesellschaft

Degussa - Huls Ag

Frank Hubner

Klaus Huthmacher

Steffen Krill

Horst Bethge

Herbert Tanner

Roland Moller

Herbert Klenk

Thomas Beisswenger

Rainer Hahn

Gerhard Sator

Karlheinz Drauz

Horst Weigel

Stephan Rautenberg

Alfred Olbrich

Rainer Gewald

Gunes Giray

Ulrich Gora

Thomas Tacke

Hans Joachim Hasselbach

Joachim Goede

Bernd Drapal

Hermann Schmitt

Claus Rehren

Nongyuan Shi

The invention relates to an improved method for the production of 2,3,5-trimethylhydroquinone by rearranging 4-oxo-isophorone (keto-isophorone, 3,5,5-trimethylcyclohex-2-en[e]-1,4-dione) to a trimethylhydroquinone diester and by its subsequent saponification. ##STR1##

Method for the production of trimethylhydroquinone

A process for the production of .alpha.-tocopherol esters, derivatives or homologs thereof of the general formula ##STR1## in which the mono- or diester of a hydroquinone is reacted with an allyl alcohol derivative or an allyl alcohol in the presence of zinc halides and proton-liberating acids at a temperature of 25.degree. to 100.degree. C.

Process for the production of .alpha.-tocopherol esters

The invention relates to the production and purification of salts of 6,8-bis (amidiniumthio)octanoic acid, its enantiomers (+)-6,8-bis(amidiniumthio)octanoic acid and (-)-6,8-bis (amidiniumthio)octanoic acid and of the esters of these compounds as well as to their use to produce dihydrolipoic acid and .alpha.-lipoic acid.

Production and use of salts of 6,8-bis (amidiniumthio)-octanoic acid

A method of producing 3,5,5-trimethylcyclohexa-3-ene-1-one (.beta.-isophorone) including a catalyst of an oxide or mixed oxide of at least one element of the groups IIa, VIII, Ib, IIIa and Va of the periodic system. Isomerization is carried out without the addition of an organic base. The space-time yield in the production of .beta.-isophorone by the isomerization of .alpha.-isophorone is at a level suitable for an industrial application. .beta.-isophorone is especially suitable as an intermediate product for producing ketoisophorone.

Method of producing 3, 5,

The present invention is relative to a method of producing dry thioctic acid in which a raw material in which concentrated thioctic acid is present is treated with liquid or supercritical CO.sub.2, thus yielding thioctic acid with low residual solvent contents in a simple industrial method.

Method of producing dry thioctic acid

An improved process for the production of 2,3,5-trimethylhydroquinone by rearrangement of 4-oxoisophorone (ketoisophorone, 3,5,5-trimethyl-2-cyclohexen-1,4-dione) to yield a trimethylhydroquinone diester and the subsequent saponification thereof. Trimethylhydroquinone is in turn an important starting material for the production of vitamin E.

Process for the production of trimethylhydroquinone diesters and of

A method of producing 3,5,5-trimethylcyclohexa-3-ene-1-one (.beta.-isophorone) by isomerization of 3,5,5-trimethylcyclohexa-2-ene-1-one (.alpha.-isophorone) in a liquid phase in the presence of a homogeneous or heterogeneous catalyst in which a mixture with a relatively low concentration of .beta.-isophorone is drawn off from the reaction container and the .beta.-isophorone isolated by vacuum distillation. .beta.-isophorone is an important synthetic structural element for the production of carotinoids, vitamins and pharmaceutical products.

Method of producing .beta.-isophorone by the isomerization of

An improved method of producing 3,5,5-trimethylcyclohex-2-ene-1,4-dione (KIP) by the oxidation of 3,5,5-trimethylcyclohex-3-ene-1-one (.beta.-IP) in the presence of managansalene-like catalysts and certain catalytic additives. ##STR1## KIP is an important intermediary product in the synthesis of trimethylhydroquinone, an initial substance in the synthesis of vitamin E. Furthermore, KIP is an initial compound for the synthesis of various carotinoids.

Method of producing ketoisophorone

The invention relates to the production and purification of salts of 6,8-bis(amidiniumthio) octanoic acid, its enantiomers (+)-6,8-bis(amidiniumthio)octanoic acid and (-)-6,8-bis (amidiniumthio)octanoic acid and of the esters of these compounds as well as to their use to produce dihydrolipoic acid and .alpha.-lipoic acid.

Production and use of salts of 6, 8-bis (amidiniumthio) -octanoic acid

A method of producing salcomine by reacting ethylene diamine with salicylaldehyde and a cobalt salt in a liquid reaction medium containing solvent.

Method of producing salcomine

RS-thioctic acid with a novel morphology which is obtained by a recrystallization process.

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Ober-Ramstadt, Germany

Frank Hubner