Bayer Aktiengesellschaft

Ferdinand Hagedorn

Helmut Fiege

Werner Evertz

Karlfried Wedemeyer

Heinz U Blank

Reinhard Lantzsch

Alexander Klausener

Hans-Joachim Traenckner

Horst Behre

Lars Rodefeld

Wolfgang Kiel

Otto Neuner

Wolfgang Eymann

Wolfgang Schenk

Rudolf Helm

Herbert Muller

Alfred Seyberlich

Robert So/ Llner

Rodulf Mayer-Mader

Provided is a process for the preparation of specific 1-substituted 2,4-dinitrobenzenes by reaction of 1-halogeno-2,4-dinitrobenzenes with mono-alkali metal salts of specific diols, in which the 1-halogeno-2,4-dinitrobenzene and the mono-alkali metal salt of the diol are simultaneously added and reacted.

Process for the preparation of 1-substituted 2,4-dinitrobenzenes

Non-explosive preparations of 1-hydroxybenzotriazole

2-Amino-6-chlorophenyl-alkylsulfanes are prepared in a particularly advantageous manner by hydrogenating 2-chloro-6-nitrophenyl-alkylsulfanes catalytically in the presence of a solvent without the addition of a further sulfur compound, and the novel compound 2-amino-6-chlorophenyl-isopropylsulfane is provided.

Process for the preparation of 2-amino-6-chlorophenyl-alkylsulfanes, and

(2RS,3RS)-3-(2'-aminophenylthio)-2-hydroxy-3-(4'-methoxyphenyl)-propionic acid methyl ester, an important precursor for the preparation of the pharmaceutical active substance diltiazem, is obtained in a particularly high stereoselectivity and yield by addition of o-aminothiophenol onto 3-(4'-methoxyphenyl)-glycidic acid methyl ester if the reaction is carried out in the presence of alkali metal salts of weak acids in the presence of catalytic amounts of iron compounds.

Process for the preparation of

A mixture of 2,4-dichloro-5-fluorotoluene and 2,6-dichloro-3-fluorotoluene which cannot be separated in an economically efficient manner and can be reacted individually to give the corresponding benzonitriles is subjected according to the invention to ammoxidation in the form of this mixture and then separated at the stage of the benzonitriles by methods known to the person skilled in the art.

Process for the preparation of 2,4-dichloro-5-fluorobenzonitrile and

4-Fluorothiophenol is obtained in outstanding purifies and yields if 4-fluorobenzenesulphonyl chloride is reacted with sodium hydrogen sulphite solution to give a solution of sodium 4-fluorobenzenesulphinate, this solution is reduced with sulphur dioxide to give 4,4'-difluorodiphenyl disulphide and finally this is reacted with sodium borohydride in a water-miscible inert organic solvent to give 4-fluorothiophenol (sodium salt). Free 4-fluorothiophenol can be isolated from the sodium salt solution by acidification.

Process for the preparation of 4-fluorothiophenol

2-Chloro-6-nitrophenyl alkyl sulphides of the formula ##STR1## in which the substituents are as defined in the description, can be prepared by reacting 2,3-dichloro-nitrobenzenes of the formula ##STR2## with mercaptans of the formula

Process for the preparation of 2-chloro-6-nitrophenyl alkyl sulphides

Methylene compounds are preferably prepared by reducing an aluminum halide complex of the formula ##STR1## in which R.sup.1 represents a C.sub.6 -C.sub.10 -aryl radical which is optionally substituted by 1 to 4 C.sub.1 -C.sub.4 -alkyl radicals, 1 to 4 fluorine, chlorine and/or bromine atoms, one C.sub.1 -C.sub.8 -alkoxy group and/or one acetoxy group, or represents a heteroaryl radical which is optionally substituted by one C.sub.1 -C.sub.4 -alkyl radical and/or one fluorine, chlorine or bromine atom and contains 5 to 10 C atoms and one O or S atom and

Process for the preparation of methylene compounds and the novel

2,2'-Dinitrodiphenyl disulphide is obtained in particularly good yields and purities in a simple manner by reacting 2-chloronitrobenzene with an aqueous alkali metal disulphide solution in the presence of phase transfer catalysts and an organic solvent.

Process for preparing 2,2'-dinitrodiphenyl disulphide

Organic compounds of reduced sulphur content and sulphur-free organic compounds can be prepared from organic mercapto and/or disulphide compounds in a particularly advantageous manner by hydrogenolytic elimination of hydrogen sulphide if the elimination of hydrogen sulphide is carried out in the presence of an organic solvent by means of an aqueous, non-oxidizing, strong acid and elemental iron, aluminium and/or zinc in the presence of catalytic amounts of nickel and/or cobalt.

Process for desulphurizing organic mercapto and/or disulphide compounds

Nitrodiphenyl(thio) ethers in which the nitro group is in the ortho- or para-position with respect to the ether oxygen or ether sulphur can be prepared from halonitrobenzones in which the nitro group is in the ortho- or para-position with respect to the halogen and, alkali metal (thio)phenolates in liquid ammonia, the reaction being carried out under pressure and at a temperature from -30.degree. C. to +140.degree. C. and the ammonia being separated off after the reaction is completed.

Process for preparing nitrodiphenyl (thio) ethers

A process for the preparation of 5-amino-2,4-dimethylacetanilide by reduction of 5-nitro-2,4-dimethylacetanilide with hydrogen is disclosed characterized in that a crude mixture containing 5-nitro-2,4-dimethylacetanilide in admixture with at least one of its position isomers is hydrogenated in a water-miscible organic solvent which optionally contains water. The 5-amino-2,4-dimethylacetanilide is separated off from the reaction mixture by means of crystallization employing a mixture of water-miscible organic solvent and water.

Process for the preparation of 5-amino-2,4-dimethylacetanilide

The invention relates to a process for the preparation of anilines which are m-substituted by chlorine, by selective dehalogenation of more highly chlorinated anilines in an acid medium in the presence of noble metal catalysts and in the presence of optionally substituted phenols. The 3-chloro- or 3,5-dichloroanilines obtainable by the process according to the invention are known intermediate products, and can be used for the preparation of plant protection agents.

Process for preparation of anilines which are m-substituted by chlorine

An improved process for the preparation of an m-halogen-substituted aniline from a polyhalogen substituted aniline by the reaction of the aniline with hydrogen in an acid medium is disclosed wherein the process is carried out in the presence of hydrogen iodide and/or a compound which under the reaction conditions yields hydrogen iodide and in the presence of an optionally substituted phenol.

Process for the preparation of m-halogen-substituted anilines

An improved process for the preparation of fused 1,2,3-triazoles by reaction of an ortho-diaminoaryl with an ester of nitrous acid in a soluent or diluent is disclosed wherein the process is catalyzed by the use of a 1,2,3-triazole.

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Leverkusen, Germany

Ferdinand Hagedorn