Abstract: 2-Alkyl-3-aryl- or -heteroaryloxaziridines are prepared in a particularly advantageous manner by oxidizing corresponding N-alkyl-aryl- or -heteroarylaldimines with an aromatic percarboxylic acid or a salt thereof in the presence of water, a water-soluble base, and a water-miscible solvent, at temperatures below 30° C. Using this method, it is also possible to obtain novel 2-alkyl-3-aryloxaziridines.

Abstract: The invention relates to a process for preparing 2,3,5,6-tetrahaloxylylidene compounds of formula (I) where each Hal is independently fluorine or chlorine, and X is fluorine, chlorine, bromine, —O—R, or —O—C(═O)R, where R is hydrogen, a straight-chain or branched C1-C12-alkyl- or a C6-C14-aryl radical, by reacting 2,3,5,6-tetrahaloxylylidenediamines of formula (II) with an alkyl nitrite and/or nitrous acid in HX as a solvent.

Abstract: 2-Alkyl-3-aryl- or -heteroaryloxaziridines are prepared in a particularly advantageous manner by oxidizing corresponding N-alkyl-aryl- or -heteroarylaldimines with an aromatic percarboxylic acid or a salt thereof in the presence of water, a water-soluble base, and a water-miscible solvent, at temperatures below 30° C. Using this method, it is also possible to obtain novel 2-alkyl-3-aryloxaziridines.

Abstract: The invention relates to a process for preparing 4-chlorobiphenyl by (a) reacting biphenyl and chlorine in the presence of one or more ring-chlorination catalysts, and (b) subjecting the reaction mixture obtained in step (a) to fractional distillation to obtain 4-chlorobiphenyl.

Abstract: The present invention relates to the preparation of nitrobenzoic acids by oxidizing particular nitrotoluenes, nitrobenzyl alcohols, esters and/or ethers in the presence of nitric acid at elevated temperature and elevated pressure. It has been found that the particular nitrotoluenes, nitrobenzyl alcohols, esters and/or ethers may be oxidized particularly reliably and in high yields using nitric acid to the benzoic acid derivatives when they are metered into the nitric acid.

Abstract: The invention relates to a process for preparing 2,3,5,6-tetrahaloxylylidene compounds of formula (I) 1

Abstract: 2-Alkyl-3-aryl- or -heteroaryloxaziridines are prepared in a particularly advantageous manner by oxidizing corresponding N-alkyl-aryl- or -heteroarylaldimines with an aromatic percarboxylic acid or a salt thereof in the presence of water, a water-soluble base, and a water-miscible solvent, at temperatures below 30° C. Using this method, it is also possible to obtain novel 2-alkyl-3-aryloxaziridines.

Abstract: The invention relates to a process for the preparation of d,l-menthol by catalytic hydrogenation of compounds which have the carbon skeleton of menthane containing at least one double bond and are 3-substituted by oxygen and/or of menthone or isomenthone or mixtures of such compounds using hydrogen at temperatures of 100 to 200° C. and at hydrogen partial pressures between 2 and 50 bar and/or by rearrangement of menthol stereoisomers in the presence of hydrogen at temperatures of 0 to 140° C. and at hydrogen partial pressures between 0.1 and 20 bar in the presence of noble-metal-containing catalysts.

Abstract: Process for the preparation of d,l-menthol by catalytic isomerization of stereoisomers of menthol or mixtures of these isomers at temperatures of from 30 to 170° C. in the presence of a supported ruthenium catalyst, the support material used being Al2O3.

Abstract: Ru/Pd catalysts on supports are used for the preparation of mixtures of substituted or unsubstituted cyclohexylamine and substituted or unsubstituted dicyclohexylamine in variable amounts by catalytic hydrogenation of substituted or unsubstituted aniline at elevated temperature and elevated H2 pressure. These catalysts are characterized in that they contain no halogen or sulphur compounds.

Abstract: A continuous process for the preparation of aromatic di- and/or polyamines by catalytic hydrogenation of the corresponding aromatic di- and/or polynitro compounds with hydrogen, characterized in that, in a reactor with a catalytic fixed bed or trickle bed at a pressure between 5 and 100 bar and a reaction temperature of from 100 to 220° C. a) the aromatic di- and/or polynitro compounds, optionally in the presence of a solvent, are introduced into a product stream comprising essentially recycled hydrogenated product, water and hydrogen, and b) a part of the product stream is removed continuously from the reactor system.

Abstract: The present invention relates to a process for the preparation of aliphatic oligocarbonate diols bya) transesterifying dimethyl carbonate with aliphatic diols in the presence of soluble transesterification catalysts in a gas-liquid countercurrent apparatus to form oligocarbonates until the degree of conversion of the initial dimethyl carbonate is more than 80% andb) removing methanol and traces of dimethyl carbonate in an apparatus which generates gas bubbles in the oligocarbonates until the degree of capping of the terminal OH groups with methoxycarbonyl groups is less than 5%.

Abstract: Catalysts containing ruthenium and palladium for the hydrogenation of aromatic amines to cycloaliphatic amines. Methods for making and using the catalysts.

Abstract: Aromatic amines are produced by catalytic hydrogenation of corresponding aromatic nitro compounds in the gas phase, by carrying out the hydrogenation in the presence of catalysts which, besides palladium, vanadium and lead, contain in addition molybdenum, tungsten and/or rhenium on a ceramic support having a BET surface area of less than 40 m.sup.3 /g, at temperatures of from 180.degree. C. to 500.degree. C. in a catalyst bed and in a molar ratio of hydrogen to the nitro group or nitro groups of 3:1 to 30:1.

Abstract: A low-pressure process for the hydrogenation of aromatic amines to give the corresponding symmetrical dicycloaliphatic amines in the presence of rhodium catalysts which are unmodified or modified by Ir, Ru, Os, Pd and/or Pt or mixtures of these metals, on supports modified by oxides of Cr, Mo, W, Mn and/or Re or mixtures of these oxides.

Abstract: The present invention relates to a low-pressure process for hydrogenating aromatic amines to give the corresponding cycloaliphatic amines in the presence of rhodium catalysts.

Abstract: A process for the production of aromatic amines by catalylic hydrogenation.

Abstract: A high-pressure process for hydrogenating aromatic amines to give mixtures of the corresponding cycloaliphatic amines and dicycloaliphatic amines in variable ratios in the presence of rhodium catalysts.

Abstract: Aromatic amines are produced by catalytic hydrogenation of nitroaromatic compounds in the gas phase. The catalyst includes palladium and lead on graphite or on a graphite-containing coke support. From 30 to 6000 equivalents of hydrogen for each equivalent of nitro groups are contacted with the catalyst during this process.

Abstract: Aromatic amines are produced by hydrogenation of the appropriate aromatic nitro compounds in the vapour phase on fixed catalysts. The catalysts contain supported metals active in hydrogenation, the reaction is carried out under adiabatic conditions at a pressure of from 1 to 30 bar, an inlet temperature of from 200.degree. to 400.degree. C. and a maximum catalyst temperature of 500.degree. C.