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:
1,2-Dichlorobenzene can be prepared by reacting 1,2,4-trichlorobenzene in the gas phase with hydrogen. The reaction is carried out at a temperature from the boiling point of the starting material up to about 400.degree. C. and over a platinum-spinel catalyst.
Abstract:
Process for the preparation of an arylglyoxylic acid of the formula Ar--CO--COOH, wherein Ar is optionally substituted aryl, which process comprises oxidizing the corresponding arylethane-1,2-diol of the formula ##STR1## with oxygen or a gas containing molecular oxygen, in an aqueous alkaline medium and in the presence of a platinum-group metal catalyst and, as an activator, a material selected from lead, lead compounds, bismuth and bismuth compounds, at a temperature of up to the boiling point of the reaction mixture; e.g. phenylglyoxylic acid is produced from phenylethane-1,2-glycol preferably using platinum activated with lead, bismuth, or compounds thereof.
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.
Abstract:
3-Fluoro-4,6-dichlorotoluene can be prepared in a particularly favourable manner by first chlorinating 3-fluorotoluene at low temperature in the presence of a Friedel-Crafts catalyst and a heterocyclic cocatalyst to give a mixture containing 3-fluoro-4-chlorobenzene and 3-fluoro-6-chlorobenzene, and subsequently, without intermediate isolation, further chlorinating this mixture, at higher temperature, after addition of further Friedel-Crafts catalyst and further heterocyclic cocatalyst, to give 3-fluoro-4,6-dichlorotoluene.
Abstract:
The new process for the preparation of 2-nitrobenzaldehydes of the general formula ##STR1## in which X.sub.1 and X.sub.2 either independently of one another represent hydrogen or halogen or one of the substituents represents nitro and the other substituent then represents hydrogen,by oxidation of 2-nitrotoluenes of the general formula ##STR2## in which X.sub.1 and X.sub.2 have the meaning indicated above is characterized in that the oxidation with oxygen or an oxygen-containing gas is carried out in the presence of at least one alkoxyalkylamine as a solvent and in the presence of strong bases.
Abstract:
Halogenated benzenes are hydrodehalogenated in a particularly advantageous manner and at low temperatures by contacting them at temperatures of between 100.degree. and 250.degree. C. together with hydrogen with a catalyst prepared by application of one or more salts of palladium and/or platinum and, if desired, of copper to an alumina or titanium dioxide support.