Abstract: A process for the preparation of 2-phenylbenzimidazole-5-sulphonic acid, characterized in that 3,4-diaminobenzenesulphonic acid is reacted at a pH between 4 and 7 in aqueous solution with 0.9 to 1.5 mol of benzaldehyde per mole of 3,4-diaminobenzenesulphonic acid and with 1.0 to 3.0 mol of SO2 per mole of 3,4-diaminobenzenesulphonic acid, or an agent which comprises 1.0 to 3.0 mol of SO2 per mole of 3.4-diaminobenzenesulphonic acid, is described.

Abstract: A process for the preparation of 2-phenylbenzimidazole-5-sulphonic acid, characterized in that 3,4-diaminobenzenesulphonic acid is reacted at a pH between 4 and 7 in aqueous solution with 0.9 to 1.5 mol of benzaldehyde per mole of 3,4-diaminobenzenesulphonic acid and with 1.0 to 3.0 mol of SO2 per mole of 3,4-diaminobenzenesulphonic acid, or an agent which comprises 1.0 to 3.0 mol of SO2 per mole of 3.4-diaminobenzenesulphonic acid, is described.

Abstract: 2-Halogenoindan-1-ones are prepared in an advantageous manner by converting anilines into diazonium salts and these, with acrylic compounds, into 3-phenyl-1-halogenoproprionic acid derivatives, and latter are cyclized.

Abstract: Quinazoline-2,4-diones are obtained in high yields and purities by reacting anthranilic acids with isocyanates and then, without isolation of the urea formed as intermediate, treating the reaction mixture with acid.

Abstract: Process for preparing haloaromatic amines by catalytic hydrogenation of the corresponding halonitroaromatic compounds, characterized in that iron-containing Raney nickel is used as catalyst, where the haloaromatic amines prepared can be used for the synthesis of photographic couplers which are useful in photographic emulsions or elements.

Abstract: 5-Fluoro-2-nitrobenzoic acid having low contents of 3-fluoro-2-nitro-benzoic acid is prepared in a simple manner by nitrating 3-fluorobenzoic acid in an anhydrous medium using an anhydrous nitrating acid and isolating and purifying 5-fluoro-2nitro-benzoic acid, by taking 7.5 to 15 parts by weight of water, based on 1 part by weight of 3-fluorobenzoic acid used, introducing the reaction mixture reacted to exhaustion into this volume of water taken, filtering off the precipitate formed and washing it with water.

Abstract: 3-Chloro-3'-nitro-4'-methoxybenzophenone with substantially lower contents of dinitro derivatives than hitherto is obtained if 3-chloro-4'-methoxybenzophenone is nitrated in from 65 to 85% strength by weight sulfuric acid with nitric acid at temperatures in the range from -20.degree. to +60.degree. C.

Abstract: Mixtures consisting essentially of cyclohexylbiphenyls, dicyclohexylbenzenes, phenylbicyclohexyls and tercyclohexyls are outstandingly suitable as heat transfer media. The mixtures can be prepared from biphenyl and cyclohexanol in the presence of bleaching earths and subsequent hydrogenation.

Abstract: Thermoplastic aromatic polycarbonates having average molecular weights Mw of at least 10,000 which contain bifunctional carbonate structural units corresponding formula (I) ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 independently of one another represent hydrogen, a C.sub.1-12 hydrocarbon, halogen,Y.sup.1, Y.sup.2, Y.sup.3 independently of one another represent hydrogen,C.sub.1-5 alkyl, a C.sub.6-12 hydrocarbon radical,at least two of the substituents Y.sup.1, Y.sup.2 and Y.sup.3 not being hydrogen and at least one of the substituents Y.sup.1, Y.sup.2 and Y.sup.3 being C.sub.1-5 alkyl,in quantities of from 100 to 1 mol-%, based on the total quantity of difunctional carbonate structural units in the polycarbonate.

Abstract: Thermoplastic aromatic polycarbonates having average molecular weight Mw of at least 10,000 which contain bifunctional carbonate structural units corresponding to formula (I) ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently of one another represent hydrogen, a C.sub.1 -C.sub.12 -hydrocarbon, halogen,m is 2 or 3 andX represents hydrogen or a C.sub.6 -C.sub.12 hydrocarbon, at least one substituent X being a C.sub.6 -C.sub.12 hydrocarbon radical,in quantities of from 100 to 1 mol-% based on the total quantity of difunctional carbonate structural units in the polycarbonate.

Abstract: Thermoplastic aromatic polycarbonates having average molecular weights Mw of at least 10,000 which contain bifunctional carbonate structural units corresponding to formula (I) ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently of one another represent hydrogen, a C.sub.1 -C.sub.12 hydrocarbon radical, halogen andR.sup.5, R.sup.6 and R.sup.7 represent hydrogen, iso-C.sub.3 -C.sub.5 -alkyl,one of the substituents R.sup.5, R.sup.6 or R.sup.7 not being hydrogen, in quantities of from 100 to 1 mol-%, based on the total quantity of difunctional carbonate structural units in the polycarbonate.

Abstract: Thermotropic aromatic polyesters which contain 3,3'-diphenyl-4,4'-dihydroxydiphenyl radicals as diphenol radicals can be processed by thermoplastic methods without decomposition, in spite of the high heat distortion resistance.

Abstract: Fully aromatic polyesters which contain 3-phenyl-4,4'-dihydroxybenzophenone radicals and/or 3-phenyl-3',4-dihydroxybenzophenone radicals as condensed units possess high mechanical properties but can still be processed without difficulties by a thermolastic method.