Bayer Aktiengesellschaft

Deutsche Gold- Und Silber-Scheideanstalt Vormals Roessler

Bayer Corporation

Hermann Seifert

Helmut Waldmann

Wolfgang Swodenk

Wulf Schwerdtel

Otto Weiberg

Gunter Prescher

Rolf Wirthwein

Gerd Schreyer

Reinhard Lantzsch

Willi Hofen

Uwe Stelzer

Herbert Klenk

Christoph Jupe

Klaus Jelich

Werner Lindner

Volker Mues

Peter Feyen

Ralf Goedecke

Achim Hupperts

Karl Steinbeck

Gebhard Rauleder

Daniel M Wasleski

David M Mayes

Gerd Siekmann

Karl-Hermann Reissinger

Helmut Waldman

Gerd Grah

Egon Kohler

Method for producing heterocyclic compounds

The present application relates to a process for preparing compounds of the formula (I)

Process for preparing heterocyclic compounds

The application describes a process for preparing 4-hydroxyanilines by the reaction of phenols with diazonium salts and subsequent reduction.

Process for preparing 4-hydroxyanilines

The invention relates to process for the preparation of an O-alkyl, O-alkyl phosphorochloridothioate by 1) reacting A) a thiophosphoryl halide with B) an alcohol, in the presence of C) a tertiary amine acid acceptor and D) a solvent, and 2) reacting the resultant product with a second alcohol, different from the alcohol used in step 1). In the preferred embodiment, the intermediate product is not isolated before reaction with the second alcohol.

Process for preparing O-alkyl, O-alkylphosphorochloridothioates

The invention relates to a new process for the preparation of 5-hydroxy-3,4,5,6-tetrahydro-pyrimidine derivatives of the general formula (I) ##STR1## in which R represents optionally substituted alkyl, which is characterized in that amidines of the general formula (II), ##STR2## in which R has the abovementioned meaning, are reacted with epichlorohydrin of the formula (III) ##STR3## if appropriate in the presence of a diluent at temperatures between 0.degree. C. and 150.degree. C.

Process for the preparation of 5-hydroxy-3,4,5,6-tetrahydro-pyrimidine

A simplified process for preparing the known insecticide 0,S-dimethylthiolphosphoric acid amide of the formula ##STR1## inexpensively, in high purity and with minimum waste water and gas which would have to be specially treated to avoid environmental pollution, comprises

Preparation of O,S-dimethyl-thiolophosphoric acid amide

The invention relates to an improved process for the preparation of polyhydric phenols by hydroxylation of phenols with peroxidic hydroxylating agents and in the presence of 0.00005 to 0.03% by weight (relative to the phenols employed) of substances which can form chelate complexes with metal ions, such as nitrogen-containing di- or poly- carboxylic acids or phosphoric acid derivatives. The products of the process are known to be useful in the fields of photography, dyestuffs, plastics, fragrances and flavors.

Process for the preparation of polyhydric phenols

A process has been developed for the purification of expoxides containing carbonyl compounds as impurities wherein the carbonyl compound content is up to 2% by weight of epoxide. Purification is effected by treatment with compounds containing at least one NH.sub.2 group.

Process for the purification of epoxides

Caprolactones such as .epsilon.-caprolactone are stabilized against discoloration with dihydroxybenzenes such as hydroquinone or compounds of the formula ##STR1## in which R.sub.1 is alkyl of 1 to 8 carbon atoms, and

Stabilizing caprolactones with dihydroxybenzenes

In a process for the continuous preparation of pure organic solutions of percarboxylic acids having 2 to 5 carbon atoms, by

Process for the preparation of percarboxylic acid solutions

A process for the preparation of .epsilon.-caprolactone comprising:

Preparation of .epsilon.-caprolactone

An improved process for the preparation of a polyhydric phenol by hydroxylation of a phenol with a peroxidic hydroxylating agent, is disclosed. The improvement resides in that before the hydroxylation, all or some of the mixture to be hydroxylated is treated with a cation exchanger.

A process for the production of pyrocatechol and hydroquinone by the hydroxylation of phenol in the nucleus with hydrogen peroxide, wherein phenol is reacted at the start of the reaction with substantially anhydrous hydrogen peroxide and wherein the reaction is carried out in the presence of a strong acid.

Process for the hydroxylation of phenol

The invention relates to a process for the provision of 5-(oxiranylmethyl)-1,3-benzodioxole by reaction of 5-(2-propenyl)1,3-benzodioxole with a percarboxylic acid having 1 to 8 carbon atoms in an inert organic solvent.

Process for the preparation of 5-(oxiranylmethyl)-1,3-benzodioxole

A process has been invented for the preparation of pyrocatechol and hydroquinone which comprises reacting a solution which is substantially anhydrous and free from hydrogen peroxide, of a percarboxylic acid in an inert, organic solvent, with phenol at temperatures from -10.degree. C. to 80.degree. C. The compounds obtained according to the invention are known, important industrial chemicals which are used in large amounts in the field of photography and of dyestuffs and plastics and in the field of scents and flavorings.

Growing community of inventors

Cologne, Germany

Hermann Seifert