Adsorptive Entfernung von Alkoxyphenolen aus Ketonen und Estern mit Aktivkohle – Experimente und Modellierung

Ultra pure chemicals are most notably used in electronics, optics, pharmaceutics and analytics. For the production of ultra pure liquids adsorptive removal of trace compounds and moisture is the preferred treatment. Adsorption experiments with the model system activated carbon/alkoxyphenol in ketones and esters as solvent are presented. Points of interest are the investigation of adsorption mechanisms as well as the measurement and modelling of adsorption isotherms.     

Adsorptive Entfernung von Schwefelverbindungen aus Erdgas

Prior to the technical use of natural gas, toxic and corrosive components need to be removed. This work provides results from dynamic fixed‐bed experiments for the adsorption of sulfurous compounds, CO₂ and H₂O from carrier gas (CH₄ or N₂) on two adsorbents (zeolite 5A, silica‐alumina‐gel) used in industrial applications. The breakthrough curves were measured at ambient conditions (298 K, 1.3 bar) in a trace level concentration range up to 2000 mol‐ppm. Adsorption isotherms were derived using mass balances and a simple linear driving force model was fitted to the curves. Good agreement of experimental data and model calculation was obtained.     

Zur Reaktion von Cyanodithioformiaten mit primären Aminen

Reactions of Cyanodithioformates with Primary Amines N-Alkyldithiooxamides 3 and N,N -dialkyldithiooxamides 4 were synthesized in good yields by reaction of cyanodithioformates 1 with primary aliphatic amines. N-Alkylcyanothioformamides 2 , intermediates in these reactions were obtained in very low yields only. The reaction of 1 and diaminoethane or 1.3-diaminopropane afforded imidazolidine-2-thione 5a respectively perhydropyrimidine-2-thione 5b . The reaction of 1 with 1-chloro-2-aminoethane did gave 2-thiocarbamoylthiazoline 7 .     

Selektivhydrierung von Fettstoffen mit metallorganischen Mischkatalysatoren nach Ziegler-Sloan-Lapporte III: Selektivhydrierung von gesättigten und ungesättigten Fettnitrilen zu gesättigten und ungesättigten,primären und sekundären Fettaminen

Selective Hydrogenation of Fats and Derivates Using Ziegler-Type Organometallic Catalysts III: Selective Hydrogenation of Saturated and Unsaturated Fatty Acid Nitriles to Saturated and Unsaturated Primary and Secundary Amines A tallow oil nitrile fraction with 66% oleonitrile and 27% stearonitrile was hydrogenated under use of homogeneous nickel- or cobalt-metallorganic catalysts from Ziegler-type with high selectivity to the corresponding saturated primary and secondary amines or under conservation of the double bond in the oleonitrile to unsaturated primary or secondary fatty amines. The realized selectivities were: 97% for stearylamine, 100% for oleylamine, 97% for distearylamine and 76% for dioleylamine.     

Kirkwoodsche Korrelationsfaktoren von binären Systemen mit Alkoholen und Diäthyläther

Kirkwood Correlation Factors of Binary Systems with Alcohols and Diethylether The KIRKWOOD theory allows the calculation of a correlation factor for describing the association of polar substances. For the systems n-hexane + diethylether cyclohexane + 1-propanol cyclohexane + 1-butanol benzene + methanol benzene + ethanol benzene + 1-propanol benzene + 1-butanol benzene + 1-hexanol benzene + 1-octanol the experimental values of dielectric constant and the calculated correlation factors are presented. From the concentration dependence of the correlation factors, calculated by use of the KIRKWOOD -FRÖHLICH -equation for mixtures, the existence of widely ramified associations of methanol and the formation of clusters of ethanol, propanol-(1), butanol-(1), hexanol-(1) and octanol-(1) is deduced. In the systems benzene + alcohol in most of the cases some specific interactions between the two components are supposed to exist.     

Zirkonium-katalysierte Oxidation von primären aromatischen Aminen zu Nitroverbindungen mit tert-Butylhydroperoxid

Zirconium-catalysed Oxidation of Primary Aromatic Amines to Nitro Compounds Using tert-Butylhydroperoxide A broad range of primary aromatic amines ( 1a–x ) with electron donating and accepting substituents are oxidized in good to excellent yields to the nitro compounds 3a–x using tert-butylhydroperoxide as the oxidant and Zr(OtBu)₄ as the catalyst. The corresponding nitroso compounds 2m, 2n, 2s and 2u can be isolated in the conversion of electron-rich anilines 1m, 1n, 1s and 1u . The aminopyridines 5a–d are also converted to the corresponding nitropyridines 6a–d , but in lower yields (41–47%).