Rutgerswerke Aktiengesellschaft

Ruetgerswerke Aktiengesellschaft

Wolfgang Weiss

Winfried Orth

Hans W Kleffner

Emmerich Pastorek

Albrecht Laufer

Stefan Sendelbach

Rolf Losch

Michael Hassler

Heinrich Miele

Bernd Rapp

Dietrich Tonnius

Josef Gotz

A process for the preparation of isomer-free 2,5-dichloropyridine comprising alkoxylating 2-chloro-pyridine or 2-bromo-pyridine in the presence of a base at elevated temperatures, chlorinating with gaseous chlorine the alkoxylated product at ambient temperatures in an aqueous suspension in the presence of an auxiliary base, a small amount of a catalyst and optionally a small amount of an emulsifier, treating the isomer reaction mixture with a Vielsmeyer-Haack reagent, subjecting 2,5- and 2,3-dichloropyridine mixture to water vapor distillation and crystallizing the crystalline product from an alcohol-water mixture.

Preparation of isomer-free 2,5-dichloro-pyridine

In the production of 9,9-bis-(4-hydroxphenyl)-fluorene by condensation by fluorenone and phenol in a molar ratio of 1:4 to 1:8 at 30.degree. to 90.degree. C. in the presence of gaseous hydrogen chloride and .beta.-mercapto-propionic acid as catalyst, the improvement comprising mixing the completed reaction mixture with a polyalkylene glycol, distilling excess phenol from the mixture, and mixing the distillation residue with a solvent miscible with the polyalkylene glycol, recovering the crystallized product, suspending the crystallized product in water and heating the suspension to obtain highly pure 9,9-bis-(4-hydroxyphenyl)-fluorene as white crystals.

Preparation of 9,9-bis-(4-hydroxyphenyl)-fluorene

In a process for the preparation of 9,9-bis-(4-hydroxyphenyl)-fluorene by condensing fluorenone and phenol in a molar ratio of 1:4 to 1:8 at 30.degree. to 90.degree. C. in the presence of gaseous hydrogen chloride and .beta.-mercapto-propionic acid catalyst, the improvement comprising distilling water of reaction and dissolved hydrochloric acid from the completed reaction mixture, dissolving the distillation residue in a nitrile, separating the crystallized adduct of nitrile and 9,9-bis-(4-hydroxphenyl)- fluorene from the nitrile and optionally dissociating the adduct to recover high purity 9,9-bis-(4-hydroxphenyl)- fluorene.

A method for the production of heavy metal-free pyridine -3-sulfonic acid by oxidation of 3-chloro-pyridine to 3-chloro-pyridine-N-oxide, substitution of the chlorine through a sulfonic acid group, and subsequent reduction to pyridine-3-sulfonic acid. The method can be carried out using raw 3-chloropyridine-N-oxide and direct further reaction of the pyridine-3-sulfonic acid-N-oxide in the presence of Raney nickel in an alkaline solution.

Production of pyridine-3-sulfonic acid

A process for the recovery of isomeric pure 7-chloro-quinaldine from isomeric mixtures of chloro-quinaldines comprising dissolving the isomeric mixture of chloro-quinaldines in an organic solvent, adding an aqueous tartaric acid solution to the organic solution to form the tartrate of 7-chloro-quinaldine in crystalline form, recovering the crystals and treating the same with a base to obtain 7-chloro-quinaldine.

Novel separation process

A process for the production of 2-hydroxypyridine from 2-chloro-pyridine which is reacted with an aqueous alkaline solution in the presence of a tertiary alcohol.

Process for the production of 2-hydroxypyridine

A process for the preparation of quinuclidine-3-methanol comprising reacting quinuclidine-3-one acid addition salt with an alkali metal cyanide in an aqueous media to obtain 3-cyano-3-hydroxy-quinuclidine, reacting the latter with anhydrous methanol in the presence of hydrogen chloride gas followed by treatment with aqueous alkali to obtain methyl 3-hydroxy-quinuclidine-3-carboxylate, reacting the latter with thionyl chloride to form methyl 1-azabicyclo(2,2,2)oct-2-ene-3-carboxylate, hydrogenating the latter with Raney nickel to obtain methyl 1-azabicyclo(2,2,2)octane-3-carboxylate and reducing the latter to obtain quinuclidine-3-methanol which is an intermediate for mequitazine which is useful as an antihistaminic.

Preparation of quinuclidine-3-methanol

Hair dye compositions based on oxidation hair dyes which contain developer components, coupling components and oxidation components, characterized in that they contain one or more aminopyrrole derivatives of the formula: ##STR1##

Hair dye composition

Improvement of the yield and purity of phenanthrenequinone during its production by oxidation of phenanthrene by means of chromic acid in a sulfuric acidic medium is achieved by preparing a dispersion made up of phenanthrene, alkali dichromate and water at 95.degree.-100.degree. C., cooling said dispersion down to 80.degree.-85.degree. C. and carrying out the oxidation reaction under cooling and portion-wise addition of concentrated sulfuric acid in a temperature range between 80.degree. and 85.degree. C.

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Neckarhausen, Germany

Wolfgang Weiss