Abstract:
Diphenylamine can be dehydrocyclized on noble metal catalysts in the liquid phase at temperatures of 200.degree. to 340.degree. C. The reaction proceeds with a surprisingly high selectivity.
Abstract:
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 formulaHS-R.sup.1 (III)in the presence of 1-1.2 equivalents of a base per mole of mercaptan and in the presence of a phase transfer catalyst, at a temperature of 0.degree.-100.degree. C., in an aqueous or aqueous-organic medium. The majority of the 2-chloro- 6-nitrophenyl alkyl sulphides obtainable in this way are novel.
Abstract:
In the preparation of m-chloroaromatics by isomerizing corresponding o- and/or p-chloroaromatics in the liquid phase over zeolites, the activity of the zeolites remains at a high level for a particularly long time if the process is carried out in the presence of from 1 to 30 mol % of hydrogen, based on the chloroaromatics used.
Abstract:
2,4- or 2,6-dihalogeno-aniline can be prepared by reacting an amino-benzoic acid ester of the formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 have the meanings indicated in the description, with 2-2.5 moles of a chlorinating or brominating agent in an inert reaction medium at a temperature of 40.degree.-160.degree. C. and subsequently hydrolyzing and decarboxylating the dihalogenated amino-benzoic acid ester.
Abstract:
Aliphatic sulphonic acids can be prepared by reacting n-paraffins with SO.sub.2 and O.sub.2 under UV irradiation with high selectivity even at conversions of up to 12 mol % if an amount of water is added which is appropriate to ensure that after the reaction has commenced and the stationary state has been reached, the sulphoxidation proceeds in homogeneous phase.
Abstract:
Alkylated aromatic amines can be isolated from crude catalyst-containing mixtures of these with olefins by a procedure in which in general equivalent amounts of an inorganic base and water are added to the alkylation mixture, the catalyst is hydrolysed, the water present in the reaction mixture after the hydrolysis is removed by distillation and the solid catalyst residue is separated off. The catalyst-free alkylation mixture which remains is then fed to customary further working up.
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:
N-Phenyl-1-naphthylamine can be prepared by reaction of aniline and 1-naphthylamine in the liquid phase at 100-400.degree. C. under normal pressure, a catalyst mixture comprising boron and fluorine being employed. Such catalyst mixtures can be obtained, for example, by reaction of hydrogen fluoride, boric acid and aniline and/or 1-naphthylamine. The catalyst is recovered and can be employed again. The reaction can be carried out discontinuously or continuously.
Abstract:
Impure POCl.sub.3 is purified by distillation in the presence of high-boiling nitrogen compounds from the group consisting of the substituted pyridines and pyrimidines, the open-chain and cyclic aliphatic amines, the open-chain and cyclic amidines, the guanidines and the aromatic amines.
Abstract:
The new process for preparing 4,4'-dinitrostilbene-2,2'-disulphonic acid and salts thereof by oxidation of 4-nitrotoluene-2-sulphonic acid with an oxidant in the presence of strong bases is characterized in that the oxidation is carried out in a mixture of water and an organic solvent selected from the group consisting of alcohols, ethers and mixtures thereof.