Hoechst Aktiengesellschaft

Freimund Rohrscheid

Gunter Siegemund

Wolfgang Appel

Jurgen Lau

Theodor Papenfuhs

Hartmut Fischer

Ludwig Brinkmann

Georg Grotsch

Jochen Rapp

Eckart Reske

Process for the preparation of brominated or chlorinated aromatic carboxylic acids The invention relates to a process for the preparation of bromine- or chlorine-substituted aromatic carboxylic acids by oxidation of the correspondingly halogenated alkylaromatics with oxygen or an oxygen-containing gas in the solvent acetic acid and in the presence of a transition metal bromide catalyst, which comprises a procedure in which

Process for the preparation of brominated or chlorinated aromatic

The present invention relates to a process for the preparation of 5-fluoroanthranilic acid, which comprises reacting 5-fluoro-2-bromotoluene in the presence of a catalyst and of an acidic solvent, with oxygen or an oxygen-containing gas at from 80.degree. to 220.degree. C., separating off the 5-fluoro-2-bromobenzoic acid formed and reacting it with ammonia at from 70.degree. to 180.degree. C.

Process for the preparation of 5-fluoroanthranilic acid

In a multi-step process, dixylylpropane is obtained inter alia via the hitherto unknown 1,2-dimethyl-4-(.alpha.-chloroisopropyl)benzene, the readily accessible compounds o-xylene and propene being employed as starting compounds. The process yields the desired compound in high yield and isomer purity and is distinguished by a small amount of by-products. It is therefore particularly suitable for further processing without problems. The process involves the sequence of (a) Friedel-Crafts alkylation of ortho-xylene with propylene, (b) dehydrogenation of the isoproplyxlene into isopropenylxylene, (c) which is then hydrochlorinated into chloroisopropylxylene, (d) and then alkylated with a second ortho-xylene modecule to obtain the final product dixylylpropane.

Process for the preparation of dixylylpropane

Compounds of the formula ##STR1## in which X represents hydrogen, --NO.sub.2 or --NH.sub.2 and Y represents --CH.sub.3, --COOH, --CONH.sub.2, --NH.sub.2 or --N.dbd.N--Z, in which the group --Z is ##STR2## with the proviso that if Y represents the group --N.dbd.N--Z, X is only --NO.sub.2, and if Y represents the group --CH.sub.3, X is only hydrogen, are described. A compound of the formula ##STR3## the preparation of which in a multi-stage process, in which the compounds of the general formula (I) are also obtained, is described, is preferred. The resulting 3,4'-diamino compound is suitable for the preparation of polycondensates and shaped articles, films and fibers of high heat resistance.

Process for the preparation of fluorine containing monomers

A compound of the formula ##STR1## and the dianhydride thereof are prepared by air oxidation in the presence of a catalyst mixture composed of at least 2 heavy metal salts and also bromine in an acid organic medium. The compounds can be employed for the preparation of partially fluorinated polycondensates, such as polyimides, polycarboxamides, esters of polyamidecarboxylic acids, polyamides and imide-oligomers.

Partially fluorinated tetracarboxylic acid and the dianhydride thereof,

Partially fluorinated dicarboxylic acid and the acid chloride thereof, a process for its preparation and its use. The compound of the formula (I) ##STR1## and the acid chloride thereof are prepared by air oxidation in the presence of a catalyst mixture composed of the ions of cobalt, manganese and bromine in an acid organic medium. The compounds can be used for the preparation of linear polycarboxamides and polycarboxylic acid esters.

Partially fluorinated dicarboxylic acid and the acid chloride thereof,

A process for the preparation of alkanesulfonylbenzoic acids from alkanesulfonylalkylbenzenes of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and are alkyl having 1 to 4 carbon atoms, but R.sup.2 has a meaning other than t-butyl, and X is H, F, Cl, Br or NO.sub.2, using molecular oxygen in acetic acid and/or propionic acid in the presence of a catalyst containing cobalt and bromine ions and, in particular when the meaning of R.sup.2 is other than methyl, also manganese ions, which is additionally carried out in the presence of metal ions of Main Group 2 and/or 3.

Process for the preparation of alkanesulfonylbenzoic acids

Partially fluorinated tetracarboxylic acid and the dianhydride thereof, a process for their preparation and their use A compound of the formula ##STR1## and the dianhydride thereof are prepared by air oxidation in the presence of a catalyst mixture composed of at least 2 heavy metal salts and also bromine in an acid organic medium. The compounds can be employed for the preparation of partially fluorinated polycondensates, such as polyimides, polycarboxamides, esters of polyamidecarboxylic acids, polyamides and imide-oligomers.

Partially fluorinated tetracarboxylic acid and the dianhydride thereof

Compounds of the formula I ##STR1## can be prepared by various process steps from 2-(4-methylphenyl)-2-hexafluoroisopropanol. Hexafluoroisopropyl-containing monomers are important starting compounds in the preparation of linear polycarboxamides and polycarboximides.

Hexafluoroisopropyl-containing monomers, process for their preparation

Partly fluorinated carboxylic acids and derivatives thereof, processes for their preparation and their use. Partly fluorinated carboxylic acids, in particular a partly fluorinated dicarboxylic acid, its acid chloride and partly fluorinated tetracarboxylic acids having various fluorine contents and their dianhydrides are obtained by atmospheric oxidation in an acid medium and at elevated temperature in the presence of a catalyst mixture of at least two heavy metal compounds and bromide ions. The compounds are used for the preparation of polycondensates and linear polycarboxylic acid amides and -carboxylic acid esters.

Partly fluorinated carboxylic acids and derivatives thereof, processes

A process for the preparation of high-purity perfluorinated compounds, specifically of an aromatic tetracarboxylic acid and its anhydride, 5,5'-[2,2,2-trifluoro-1-(trifluoromethyl)-ethylidene]bis-1,3-isobenzofuran dione, by a multi-step treatment of the crude compounds. The metal ion content of the compounds treated is reduced considerably. After polymerization with an aromatic diamine, the anhydride is used in microelectronics.

Process for the preparation of high-purity

The invention relates to a process for the isolation of p-hydroxybenzaldehyde from the reaction mixture obtained by oxidizing p-cresol with oxygen or oxygen-containing gases in methanol in the presence of Na or K hydroxide and an Mn, Ni, Cr or Co salt. The procedure in this process is optionally to add water to the reaction mixture, to heat the resulting solution and to filter off the precipitated Mn, Ni, Cr or Co oxide-hydrate, to remove the methanol from the filtrate by distillation, to cool the residual aqueous solution and thus to allow the p-hydroxybenzaldehyde to crystallize out in the form of the Na or K salt. Alternatively, the reaction mixture is first dried by atomization, the soluble constituents of the dry substance are then dissolved in hot water, the undissolved Mn, Ni, Cr or Co oxide-hydrate is filtered off and the salt of p-hydroxybenzaldehyde is again allowed to crystallize out by cooling the filtrate. A further method consists in diluting the reaction mixture with methanol, filtering off the undissolved Mn, Ni, Cr or Co oxide-hydrate, drying the filtrate by atomization, dissolving the resulting dry substance in hot water, and again allowing the p-hydroxybenzaldehyde to crystallize out as the Na or K salt by cooling the solution.

Process for the isolation of p-hydroxybenzaldehyde

Naphthalene-1,4,5,8-tetracarboxylic acid and typical derivative(s) thereof is (are) prepared by oxidation of periacenaphthindenones of the formula ##STR1## where R is H or lower alkyl, in a lower aliphatic carboxylic acid with nitric acid, optionally using also oxygen, in the presence of oxidation catalysts at temperatures above about 100.degree. C; the reaction product being worked up in known manner. Naphthalene-1,4,5,8-tetracarboxylic acid is an important preliminary product for the manufacture of dyestuffs.

Process for the preparation of naphthalene-1,4,5,8-tetracarboxylic acid

There are disclosed and claimed novel polyamides having improved properties such as high transparency and second order transition temperatures in combination with good mechanical and electrical properties at relatively high temperatures. These polyamides are derived from bis-aminomethyl-norbornanes and aliphatic or cycloaliphatic or aromatic or aromatic-aliphatic diamines, aliphatic or aromatic dicarboxylic acids, and amino carboxylic acids.

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Kelkheim, Germany

Freimund Rohrscheid