Hoechst Aktiengesellschaft

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Michael Mitzlaff

Hans Joachim Metz

Harald Jensen

Kurt C Habig

Theodor Papenfuhs

Gunter Siegemund

Georg Schaeffer

Konrad Baessler

Gunter Keil

Friedrich Herold

Siegfried Planker

Joachim Hackenbruch

Franz Jakob

Bettina S Herbst

Gunter H Herbst, Deceased

Ulrike M Herbst

A process for the production of fluorobenzaldehydes which comprises reacting a chlorobenzaldehyde with an alkali fluoride in a dipolar aprotic medium.

Process for the preparation of fluorobenzaldehydes

Process for the continuous preparation of 3,3'-dichloro-benzidine

Process for the preparation of 4-chloro-2,5-dimethoxyaniline by catalytic reduction of 4-chloro-2,5-dimethoxynitrobenzene with hydrogen in the liquid phase at an elevated temperature and elevated pressure, which comprises carrying out the reduction at temperatures from about 80.degree. to about 110.degree. C. and under a pressure of about 5 to 50 atmospheres gauge in an aromatic solvent in the presence of a modified platinum-on-carbon catalyst in the presence of about 0.01 to about 0.2 mole of a compound which gives a pH of 8 to 10 in aqueous solution, and in the presence of about 0.1 to about 1.0% by weight of an aliphatic, open-chain, primary, secondary or tertiary amine or a cyclic amine, in each case relative to the amount in moles and weight, respectively, of 4-chloro-2,5-dimethoxynitrobenzene employed.

Process for the preparation 4-chloro-2,5-dimethoxy-aniline

A process for the preparation of halogen-containing aromatic compounds of the formula ##STR1## wherein Hal represents fluorine, chlorine or bromine and Z represents an aromatic group which comprises reacting a halobenzene of the formula C.sub.6 H.sub.5 Hal (II) under anhydrous conditions with a halide of a bisacid having the formula Hal-CO-Z-CO-Hal (III) in a molar ratio of at least 2:1 in the presence of a haloalkane sulfonic acid of the formula Y(C.sub.n X.sub.2n)SO.sub.3 H (IV), in formulae II and III Hal and Z having the afore-mentioned meaning and Y representing fluorine or hydrogen, X at least one of fluorine and chlorine, but at least one X being fluorine, and n being an integer of from 1 to 10. The said bis-(4-halobenzoyl) compounds being useful monomers for chemically resistant plastics which are still resistant even at high temperatures.

Process for the preparation of halogen-containing aromatic compounds

Process for the preparation of 2-nitro-3-aminopyridine, and the

Aromatic bromine compounds are prepared by reacting aromatic nitro compounds with elemental bromine in the gas phase at temperatures between about 310.degree. to 550.degree. C. In this reaction, the nitro groups are selectively replaced by bromine; further bromination of the aromatic system beyond that does not take place.

Process for preparing aromatic bromine compounds

The invention relates to filaments, fibers, pulps, films and sheets from a copolyamide which has at least the recurring structural units of the formulae

Shaped structure of aromatic copolyamide from aromatic diamine mixture

Special cyclic enamides are prepared by splitting off alcohols catalytically from the corresponding alkoxylated cyclic amides, in the presence of at least one tetraalkylammonium and/or alkali metal salt of tetrafluoroboric acid and/or of hexafluorophosphoric acid as the catalyst, at a temperature of from about 120.degree. to 250.degree. C., distilling off the detached alcohol and isolating the formed enamide in known manner. Particularly preferred starting compounds are those cyclic amides which have been obtained by anodic alkoxylation of corresponding cyclic N-compounds in an alcohol in the presence of supporting electrolytes which are identical with the catalysts subsequently used for splitting off the alcohol, and by distilling off the alcohol from the reaction batch. The enamides are valuable starting products and intermediates for various syntheses, for example, syntheses of prostaglandins and of other pharmaceuticals.

Process for the preparation of cyclic enamides

Novel alkoxy derivatives of N-substituted cyclic amines of the formula ##STR1## where R.sup.1 is hydrogen, an alkyl group having from 1 to 8 carbon atoms, an aryl group having from 6 to 10 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, an aralkoxy or aroxy group,

Process for preparing fungicidal monoalkoxy and dialkoxy N-substituted

.omega.,.omega.-Dialkoxycarboxylic acid derivatives I (amides and esters) are prepared by heating .omega.-alkoxylactams II with hydrogen halide in an alcohol. When using only a catalytical quantity of hydrogen halide, there are obtained the amides, when using a quantity of hydrogen halide which is at least about equimolar, there are obtained the esters of the corresponding .omega.,.omega.-dialkoxycarboxylic acids. Since the compounds I are acetals, they may be readily converted into the corresponding .omega.-formyl compounds. Both the acetals I and the corresponding .omega.-formyl compounds are valuable intermediates for the synthesis of for example prostaglandins, sexual attractants and antioxidants.

Process for the preparation of .omega.,.omega.-dialkoxycarboxylic acid

Trimeric piperideins and trimeric pyrrolidine are prepared by saponification of 1-acyl-2-alkoxypiperidines or pyrrolidines of the general formula ##STR1## in which n means 2 or 3 R.sub.1 represents hydrogen or a linear or branched C.sub.1 -C.sub.4 alkyl radical and

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Eppstein/Taunus, Germany

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