Ciba-geigy Corporation

Ciba-geigy Ag

Givaudan Corporation

Grant S.a.

Eric Plattner

Christos Comninellis

Gottfried Seifert

Jacques Bersier

Horst H Jager

Tibor Somlo

Sebastian Staubli

Otto W Gordon

Frank Doppenberg

Fred Von Kaenel

Martin Burli

Hans-Ulrich Herrmann

Robert U Osterwalder

Production of pulp by the soda-anthraquinone process (SAP) with recovery

A process for the preparation of 5-nitro-1,4-naphthoquinones of formula ##STR1## wherein R is hydrogen, a C.sub.1 -C.sub.4 alkyl radical or a C.sub.1 -C.sub.4 alkoxy radical, by oxidation of 1-nitronaphthalene or a suitably substituted 1-nitronaphthalene, which process comprises carrying out the reaction with manganese(III) sulfate as oxidizing agent or a mixture of manganese(III) sulfate and cerium sulfate. The maganese(III) sulfate consumed can be regenerated electrolytically with good current yield. The process is environmentally safe, as the oxidizing agent and the solvent, if any, can be reused.

Process for the preparation of 5-nitro-1,4-naphthoquinone

There is disclosed a process for the preparation of 1-aminoanthraquinones from 5-nitro-1,4,4a,9a-tetrahydroanthraquinones with a basic reducing agent, which process is carried out under pressure in the temperature range above 100.degree. C. and in an aqueous-organic medium. The process affords very pure 1-aminoanthraquinone, which is, inter alia, an important intermediate.

Process for the preparation of 1-aminoanthraquinones

Process for the manufacture of an aldehyde

The invention describes a process for the production of benzanthrone by reacting anthraquinone with glycerol and/or acrolein, using anthrone as reducing agent. Benzanthrone is an important intermediate for dyes and is used in particular for the preparation of vat dyes.

Process for the production of benzanthrone

The invention relates to an improved process for the production of 2-amino-1-naphthalenesulfonic acid (Tobias acid). This improved process makes it possible to obtain Tobias acid which has only a very low content of 2-aminonaphthalene and in high space-time yield. The process starts from 2-hydroxynaphthalene and comprises the following main reaction steps:

Process for the production of 2-amino-1-naphthalenesulfonic acid

An electrochemical process for the preparation of benzanthrones and planar, polycyclic aromatic oxygen-containing compounds is described. The process is carried out in an acid medium in an electrolytic cell which is separated by a diaphragm into a cathode compartment and an anode compartment. In the cathode compartment, anthraquinone or an anthraquinone derivative is reduced electrolytically to oxanthrone and the latter is reacted with glycerol to give the corresponding benzanthrone. In the anode compartment, a transition metal ion is simultaneously converted electrolytically from a lower oxidation stage into the next higher oxidation stage. The metal ion of higher valency is then used in the anolyte as an oxidizing agent by means of which the corresponding oxygen-containing compounds are obtained, starting from planar, polycyclic aromatic compounds.

Electrochemical process for the preparation of benzanthrones and planar,

A process for the manufacture of sulphonic acid fluorides of the formula RSO.sub.2 F, wherein R represents a straight-chain or a branched alkyl or cycloalkyl radical is provided. The process is carried out in liquid hydrogen fluoride and comprises reacting thio compounds of the formula R--S--X, wherein R has the indicated meaning and X is hydrogen or --S--R, with nitrogen dioxide and/or dinitrogen tetroxide. The obtained sulfonic acid fluorides are useful intermediates for the manufacture of a great number of other compounds. By means of electrochemical fluorination they can also be converted into the corresponding perfluoroalkylsulphonic acid fluorides, which can be used as a basis for oil and water repellants.

Process for the manufacture of sulphonic acid fluorides

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Seltisberg, Switzerland

Eric Plattner