Über die Autoxydation gesättigter Fettsäuren IV: Sauerstoff-Verbrauch und Bildung von Peroxiden bei der Oxydation von Laurin- und Stearinsäure sowie ihrer Methylester

Autoxidation of Saturated Fatty Acids IV: Oxygen Consumption and the Formation of Peroxides in the Oxidation of Lauric and Stearic Acids and their Methyl Esters The investigation showed a reproducible course of oxygen uptake and peroxide formation. In the oxidation of free acids the oxygen uptake was considerably higher than the corresponding peroxide content. The amounts of peroxides determined are so small that secondary reactions may be assumed to occur at relative ease under the experimental conditions. The higher content of peroxide compounds in the oxidation of methyl esters compared to that in the oxidation of free acids indicated a hindrance of the subsequent reactions which are associated with the decomposition of the peroxides. The experiments showed that initially an unusually large part of the absorbed oxygen is consumed in the formation of peroxides. The formation of split products can therefore occur here only with great difficulty in contrast to the case of free acids.     

Darstellung und Reaktionen von 2-Mercapto-6-thioxo-thiopyran-3-carbonsäure-Derivaten

Synthesis and Reactions of 2-Mercapto-6-thioxo-thiopyran-3-carboxylate derivatives 6-Amino-thiopyran-2-thiones ( 1 ) react with dihydrogen sulfide in the presence of pyridine and triethyl amine to yield 6-thioxo-thiopyran-2-thiolates ( 2 ). Methylation of 2 gives the methylthio compounds 3 and 4 . Further methylation of 3a and 4a yields the thiapyrylium salt ( 7 ). The reaction of 2-imino-thiopyran ( 6 ) with carbon disulfide represents another route to the 6-methylthio-thiopyran-2-thione ( 4a ). The 2-methylthio-thiopyran-6-thione ( 3a ) undergoes substitution of the methylthio group with amines to 8 or reacts with phenylhydrazine to phenylhydrazono-thiopyrane ( 9c ). 6-Thioxo-thiophen-2-thiolates ( 2a , b ) react with hydrazine hydrate to give hydrazono-thiopyranes ( 10a , b ) which can be S-methylated. On the contrary 2c gives with hydrazine hydrate under ring transformation the pyridine-2-thiolate ( 11 ). N,S-Acetals ( 12 ) and 1,3,4-thiadiazoles ( 15 ), which give rise to new pyridine derivatives ( 14 ) and ( 17 ), can be obtained from 1-Amino-pyridin-2-thiolate ( 11 ).     

Darstellung und Reaktionen von α-Halogenbenzyl-silanen

Preparation and Reactions of α-Halogenobenzyl-silanes α-Bromobenzyl-dimethylchlorosilane 3 , bis-(α-bromobenzyl)-dimethylsilane 8 and the corresponding α-chlorobenzyl-compounds 5 and 13 have been prepared by reaction of benzyl-dimethylchlorosilane 1 resp. dibenzyl-dimethylsilane 2 with N-bromosuccinimid and sulfurylchlorid. The α-halogenobenzyl-dimethylchlorosilanes 3 and 5 have been treated with water, alcohols and phenol, to give the corresponding silanols 15 and 16 , siloxanes 17 and 18 , alkoxy- and phenoxysilanes 19 and 20 . Reactions of 3 with brenzcatechin, o-aminophenol and o-aminobenzylalcohol give 6- resp. 7- membered silaheterocycles 21 – 23 .     

Über die Autoxydation gesättigter Fettsäuren V: Angriff des Sauerstoffes und Bildung von Peroxiden bei der Oxydation von Laurin- und Stearinsäure sowie ihrer Methylester

Autoxidation of Saturated Fatty Acids V: The Attack of Oxygen Consumption and the Formation of Peroxides in the Oxidation of Lauric and Stearic Acids and their Methyl Esters No unsaturated compounds were found amongst the products of oxidation. Alkan-2-ones and alkanals containing one C-atom lesser than the fatty acid chain were identified as the primary products of degradation of the acids and esters. From the composition and periodic occurrence of the products of degradation, one can conclude that preferentially a β-oxidation takes place. The formation of alkanals having chain lengths shortened by one C-atom than the starting materials indicate the occurrence of α-oxidation as well, which, however, lags far behind the β-oxidation.     

Alkylendiamide und Alkylendiisoimide von Äthyleniminocarbonsäuren und -dicarbonsäuren

Alkylenediamides and Alkylenediisoimides from Ethyleneimino Carboxylic Acids and Ethyleneimino Dicarboxylic Acids Preparation and properties of some alkylenediamides from β-ethyleneiminopropionic acid and ethyleneiminosuccinic acid as well as of two alkylenediisoimides of ethyleneiminosuccinic acid are described.     

Darstellung und Reaktionen von 2-Arylamino-3-nitrochinolinen

Synthesis and Reactions of 2-Arylamino-3-nitroquinolines Condensation of 1-nitro-2,2-bis(methylthio)ethylene with esters of anthranilic acid yields 2-arylamino-3-nitro-4-quinolones. 2 . Analogously, from 1-nitro-2-anilino-2-methylthioethylene and o-aminoketones, 2-anilino-3-nitroquinolines 4 are obtained which can be reduced to 2-anilino-3-amino-quinolines 7 . The latter undergo cyclizations by usual methods to yield substituted triazolo-, imidazolo-, diazepino- and pyrazino-quinolines 9–12 . Reaction of ethyl-2-aminothiophene-3-carboxylates with 1-nitro-2-anilino-2-methylthio-ethylene affords 2-anilino-3-nitrothieno[2,3-b]-4-pyridones 5 .     

Darstellung,Reaktionen und spektroskopische Charakterisierung von Zweikernaromat-metall-tricarbonyl-Komplexen

Preparation, Reactions, and Spectroscopic Characterization of Di(tricarbonylmetal) Complexes of Dinuclear Arenes Di(tricarbonychromium) complexes of dinuclear arenes have been prepared by direct reaction of the dinuclear arene with hexacarbonylchromium or by an arene exchange reaction with tricarbonyl(dimethyl terephthalate)chromium. Infrared and ultraviolet spectroscopic studies show that both tricarbonylchromium groups are structural units being practically independent of each other. On the other hand, there obviously occur distinctions to the behaviour of the mononuclear complexes both during the mass spectrometric and the photolytic decay. After ultraviolet irradiation of solutions of the complexes and acrylonitrile, in tetrahydrofurane, acrylonitrile compounds of the dinuclear complexes have been detected but could not be isolated as pure substances due to their instability. Some of the prepared complexes act under hydrogenating conditions in an autoclave versus acrylonitrile as hydrogenating catalysts, but in no case as dimerizing catalysts.     

Darstellung und Reaktionen von 2-Arylazo-2-nitro-keten-aminalen

Synthesis and Reactions of 2-Arylazo-2-nitro-keten Aminals N,N′-Disubstituted 1-nitro-2,2-diamino ethylenes 1 undergo azo-coupling to form the title compounds 2 . Their treatment with oxalyl chloride yields the imidazolidin-4,5-dione-derivatives 4. 2 react with phosgene and thiophosgene to form 6-nitro-2,4-diaryl-5-arylimino−2,3,4,5-tetrahydro-1,2,4-triazin-3-ones 5 and -thiones 6 respectively. From 2 and N-(dichloromethylene)-arylsulfoamides the 6-nitro-2,4-diaryl-5-arylimino-3-aryl-sulfonylimino-2,3,4,5-tetrahydro-1,2,4-triazines 7 arise. The reduction of 2 yields the substituted oxalic amidines 9     

Aspekte bei der Hydrierung von Fetten und Fettsäuren

Aspects of Hydrogenation of Fats and Fatty Acids Hydrogenation of fat products is of great significance, both for human and animal nutrition as well as for technical purposes. In the area of nutrition, adequate food for the increasing world population is unthinkable without utilization of all fat resources, that can be made available as food fats only after catalytic hydrogenation. In the area of technical use, a similar development is observed owing to shortage of mineral oils. Thus, fatty alcohols derived from vegetable oils and waxes can already compete in price with fully synthetic fatty alcohols derived from mineral oils. In the past 70 years of hydrogenation of fats till the present time, catalysts based on nickel have been most commonly used. In addition, small proportions of catalysts based on copper and noble metals have also been used. Homogenous catalysts have been used very recently. The present communication deals primarily with the hydrogenation of neutral fats and fatty acids using nickel catalysts. The aspects of selectivity and isomerization in the partial hydrogenation of neutral fats are discussed. In the hydrogenation of fatty acids and their derivatives, emphasis is laid on other factors, such as activity, poisoning and acid resistance of the catalyst. These factors are discussed.     

Konduktometrische und spektroskopische Untersuchungen der Wechselwirkung von Lewis-Säuren mit Halogenkomplexen

Conductometric and Spectroscopic Investigations of the Interaction of Lewis Acids with Halide Complexes The interaction of counter ions with Lewis acids has been investigated using mode systems of the type (C₆H₅)₃C^⊕ MX_n+1^⊖ (M = Sb, As, B, Fe; X = Cl, F) by means of conductometrical and UV-spectroscopic methods. The changes of conductivity were strongly dependent on the nature and concentration of the Lewis acid. The results point to 1:1-complexes between Lewis acids and counter ions. The behaviour was found to be complicated by dissoziation resp. assoziation processes. Ligand exchange reactions between Lewis acid and counter ion have also been found.     

Darstellung neuer substituierter 1,2,4-Triazin-6-carbonsäuren und 1,2,4-Triazin-6-yl-alkancarbonsäuren

Synthesis of New Substituted as-Triazine-6-carboxylic Acids and as-Triazine-6-yl-alkanoic Acids New substituted 3-amino-, 5-amino- and 3,5-diamino-as-triazine-6-carboxylic acids 4a , b , 5a , b and 6 were obtained by the hydrolysis 6-azalumazine derivatives 3a – e . Corresponding acids of the structure 10a – d , 11a , b and 12 were synthesized from 5-chlor-3-methylthio-astriazine-6-carboxylic-ester 8 . The synthesis of new 3-alkylthioderivatives of as-triazine-6-yl-acetic acid 16a – c and -propionic acid 18 and its hydrolysis to 3,5-dioxotetrahydro-as-triazine-6-yl-propionic acid 19 is reported.