Intramolekulare 1,3-dipolare Cycloadditionen von Arylaziden mit Alkinylsubstituenten

Intramolecular 1,3-Dipolar Cycloadditions of Aryl Azides with Alkynyl Substituents Reaction of substituted 4-chlorobut-2-ynes 1 with 2-acetaminophenol and 2-aminothiophenol, respectively, leads to the corresponding ethers and thioethers 3 that can be converted into the alkynyl substituted aryl azides 4 by diazotation and reaction with sodium azide. Intramolecular 1,3-dipolar cycloaddition yields 4H-[1,2,3]triazolo [5,1-c] [1,4] benzoxazines and benzothiazines 5 . In the same way 1,4-bis(2-acetaminophenoxy)but-2-yne 6 reacts to a 3-(2-azidophenoxy-methyl)-triazolobenzoxazine 9 . Its thermal decomposition gives the azomethine 11 .     

Synthese von 5-Hetaryl-1,3-dithiol-Derivaten durch Reaktion von Hetarylmethyl-dithiokohlensäurediestern mit Schwefelkohlenstoff

Synthesis of 5-Hetaryl-1,3-dithiole Derivatives by Reaction of Hetarylmethyl-dithiocarbonates with Carbon Disulfide (Pyrid-2-yl)- and (quinol-2-yl)-dithiocarbonates 4 and 7 cyclocondense with carbon disulfide to yield 4,5-disubstituted 1,3-dithiole-2-thiones 5 and 8a – d after alkylation reaction. 8 is transformed into the 2-oxo-derivatives 9 by reaction with mercuric acetate. A series of heterocyclic substituted dithiocarbonates 10a , 10b , 12a , 12b , and dithiocarbamates 12c – g , respectively, is synthesized by reactions of halomethylheterocycles with the corresponding salts of xanthates or dithiocarbamates.     

Synthese substituierter N-Hydroxylactame,Lactame, Chinolin-N-oxide und Chinoline durch katalysierte Reduktive Cyclisierung von 2-Nitrocinnamoyl-Verbindungen mit Wasserstoff/Platinschwarz

Synthesis of Substituted N-Hydroxylactams, Lactams, Quinoline-N-oxides, and Quinolines by Catalyzed Reductive Cyclization of 2-Nitrocinnamoyl Derivatives with Hydrogen/Platinum Black Substituted nitrobenzenes 1a–1m , consisting of two series of 6 analogous compounds, containing the structural unit of an α,β-substituted 2-nitrocinnamoyl group have been reductively cyclized by means of hydrogen in the presence of platinum black catalyst to form four types of heterocycles: N-hydroxylactams 2a and b , lactams 3 and 4 , quinoline-N-oxides 5a–d , and quinolines 6a and b . The type of substituents at the 2-nitrocinnamoyl group is of significance for the type of heterocycle formed in this reaction. It is of special interest that by the use of the reduction system hydrogen/platinum black the probability to obtain N-hydroxylactams or quinoline-N-oxides, which are difficult to obtain by alternative procedures, becomes much higher than by the use of many reducing agents acting noncatalytically.     

Synthese von 4-Alkoxy-2-hydroxyphenylketoximen als Metallextraktions-Reagenzien

Synthesis of 4-Alkoxy-2-hydroxyphenyl Ketoximes as Reagents for Metal Extraction The C-Acylation (Friedel-Crafts reaction) of resorcinol with aluminium chloride, the monoetherification in 4-position of the resulting 2,4-dihydroxyphenylketones, and the preparation of oximes ( 8, 9, 10, 11 ) from this ketones were investigated. The compounds obtained are characterized by elemental analysis, and the i.r., u.v. and ¹H-n.m.r. spectra are discussed. Solubility data of some oximes are determined in water, octane and toluene. The extraction properties for copper-(II)-and iron-(III)-ions are measured by isotope methods in relation to the extragent structure, the extraction time and the pH-range.     

Synthese von Dibenzo-tetrathiafulvalenen mit 1,3-Dithiol-2-yl-phosphonsäureester-Struktur

Synthesis of Dibenzo-tetrathiafulvalenes Containing 1,3-Dithiol-2-yl-phosphonic Ester Structures 1,3-Dithiol-2-ylphosphonate esters ( 3a-d ) with a dibenzo-tetrathiafulvalene unit were synthesized directly from trialkylphosphite and 6,6′-dioxo- ( 2a , c ) and 6,6′-dithioxo-4,4′,8,8′-tetrakis(alkylthio)-2,2′-bi-1,3,5,7-tetrathia-s-indacenylidenes ( 2b , d ). The influence of the type of trialkylphosphite, of the reaction temperature and the solvent on the regioselectivity of the reaction was studied. In toluene the tristetrathiafulvalene ( 4c ) was exclusively obtained from 2c .     

Synthese von Cyclobutan durch Dehalogenierung von 1,4-Dihalogenbutanen mit Alkalimetalldämpfen. Zur Relation von radikalischen und metallorganischen Reaktionskanälen

Synthesis of Cyclobutane by Dehalogenation of 1,4-Dihalogenbutane in Alkali-Metall-Bathway. The Relation of Radical and Metallorganic Reaction-channels. Gasphase dehalogenation of 1,4-dichloro-, 1-chlor-4-bromo, 1,4-dibrombutanes and 1,4-dibrompentane by Na/K vapors produces cyclobutane resp. methylcyclobutane with selectivities of resp. 55.5, 46.7, 32.0 and 17 moles/100 moles. Side products of the reaction are ethylene and hydrogen, yields of which increase with increasing temperature and rising degree of substitution of chlorine by bromine. A mechanism is discussed in which the initiation step is the generation of halobutyl radicals of the type H₂Ċ (CH₂)₂ CH₂X (X = Cl, Br) which are reacting further in two ways – by formation of tetramethylenediradical, splitting off the second halogen atom, or by the formation of the metallorganic compound 1-kalium-4-halogenbutane, which further cyclisize to cyclobutane splitting off KX. Using some methods of theoretical chemistry such as quantumchemical calculations based on ab initio (STO-3G) and semiempirical (AM1) structures, on the relative energies of conformeres of halogenbutylradicals and on models of the metallorganic intermediates, but also by conformation calculations of the content of rotation isomers of the intermediate formed, the correlation between the two reaction channels in dependence of the type of halogen was estimated. The calculations showed, that only about 20% of cyclobutane are generated by the radical pathway. The high predominance of the metallorganic channel in the case of 1,4-dichlorbutaneis caused by the high lifetime of chlorobutyl radicals in comparison with his bromoanalogues.     

Synthese von nitro- und aminosubstituierten Thiobenzamiden durch Thiolierungsreaktionen mit elementarem Schwefel unter milden Bedingungen

Synthesis of Nitro- and Amino-Substituted Thiobenzamides by Thiolation Reactions with Elemental Sulfur at Mild Conditions The Synthesis of thiobenzamides 2 – 7 by basecatalyzed thiolation of nitro-benzyl-halides (type 1 ), especially at low temperatures, and the selective synthesis of p- and m-nitro-thio-benzamides ( 2 , 3 ) or p-and m-amino-thiobenzamides ( 5 , 6 ), respectively, are described. o-Nitro-benzylhalides (→ 4 , 7 ) are less reactive than p- and m-nitro-benzylhalides. The reaction of nitrobenzylhalides (type 1 ) with elemental sulfur and amines occuring at low temperatures to give 2 – 4 leads via structures of the type 11 , 15 and 16 .     

Synthese und Reaktionen von 1,3-Azaphosphorinan-2-thionen

Synthesis and Reactions of 1,3-Azaphosphorinane-2-thiones Aminopropylphosphines, R P(H) (CH₂)₃ NH₂, react with carbon disulfide to give 1,3-azaphosphorinane-2-thiones. In presence of strong bases the title compounds are converted by alkyl halides into 2-alkylthio-3, 4, 5, 6-tetrahydro-1, 3-azaphosphorines whereas in absence of bases quaternization at the phosphorus atom occurs to give 2-thiono -1,3-azaphosphorinanium salts. The structures of the compounds prepared are elucidated by IR. ¹H-n.m.r. and mass spectra.     

Zur Synthese von Octahydrochinazolinonen und deren Reaktion mit Persäure

The Synthesis of Octahydroquinazolinones and their Reaction with Peracid By reaction of cyclohexanone-2-carboxamide with ammonia and aldehydes, octahydroquinazolinones 2a–f , and with Schiff bases octahydroquinazolinones 3a–c are formed. 2-Hydroxycyclohexanone-2-carboxamide forms with ammonia and butyraldehyde the hydroxyocta-hydroquinazolinone 4 . Compound 2e reacts with monoperoxiphthalic acid to the hydroxyoxaziridine 5e which reacts with alkali hydroxide to compound 6. 8 yields with peroxy acid the hydroperoxy epoxide 9 .     

Synthese und physiko-chemisches Verhalten von Lecithinen mit verzweigten Fettsäureresten

Synthesis and Physico-chemical Behaviour of Lecithins with Branched Fatty Acid Chains Branched fatty acids widely occur as components of the lipids of microorganisms, plants and animals. For studying the biophysical and biochemical behaviour of lecithins with branched fatty acyl, we synthesized three series of glycerophosphocholines. For this purpose fatty acids (palmitic, stearic acid) with a methyl group in different positions and α-branched fatty acids with alkyl residues of different lenght were synthesized and incorporated into 1,2-diacyl-, 1-acyl-2-O-hexadecyl- and 1-O-hexadecyl-2-acyl-glycerophosphocholines. The resulted lecithins were characterized biophysical (differential scanning calorimetry, X-ray diffraction) and biochemical (interaction with phospholipase A₂).     

Durch bisquartäre Ammoniumsalze katalysierte Zweiphasenreaktion von 1-Bromoctan mit Natriumacetat und Kaliumacetat

Two-Phase Reaction of 1-Bromooctane with Sodium Acetate and Potassium Acetate Catalyzed by Diquaternary Ammonium Salts New unsaturated diquaternary ammonium salts (diquats) were prepared in two ways from ditertiary amines 3 and 1-bromoalkanes or from 1, 4-dibromobut-2t-ene and tertiary monoamines. A comparison of their catalytic ability with that of saturated diquats and with that of corresponding monoquats was made. The reaction of n-C₈H₁₇Br with NaOAc or KOAc in the two-phase system liquid-liquid without an additional solvent is catalyzed more effectively by the unsaturated diquats than by the saturated diquats and the monoquats. Most of the used quats catalyze the ester formation from NaOAc more effectively in the system liquid-liquid, however, the ester formation from KOAc more effectively in the system solid-liquid; KOAc is generally superior to NaOAc in both systems. Consequently, in the phase-transfer catalyzed ester formation from alkali acetate and alkyl halides not only the structure of the quat but also the inorganic cation of the acetate have influence on the rate of conversion.     

Synthese von Aldehyden und Carbonsäuren durch katalytische Oxidation vicinaler Diole

Synthesis of Aldehydes and Carboxylic Acids by Catalytic Oxidation of Vicinal Diols Results of studies on oxidative cleavage of aliphatic vicinal diols by oxygen in the presence of cobaltous compounds are reported. The effect of experimental conditions on the yield of aldehydes and acids are presented. Yields of 90% resp. 86% of these compounds are obtained.     

Zur Synthese von 3-Amino-pyrrolen durch Thorpe-Ziegler-Cyclisierung

On the Synthesis of 3-Amino-pyrroles by Thorpe-Ziegler-Cyclization N-Aryl and alkylaminomethylene cyanacetic acid derivatives 1 react with α-halogencarbonyl compounds 2 in the presence of potassium carbonate/sodium ethoxide to yield the substituted 3-amino-pyrroles 6. Using the same principle of cyclization pyrrole derivatives 6 can also be obtained by reaction of β-chloro- and β-alkoxymethylenemalononitriles 4 with β-aminocarbonyl compounds 5. From the malononitrile derivatives 1 containing the methylthio group in the β-position, and α-halogen ketones 7 , the 2-dicyanomethylene oxazolines 8 arise which undergo alkoholysis by treatment with sodium alkoxide to form the 3-amino-5-alkoxy-pyrrole derivatives 9 .     

Synthese und Konformationsanalyse von Pyranophanonen und Pyrylophanium-Verbindungen mit intraannularen Substituenten

Synthesis and Conformational Analysis of Pyranophanones and Pyrylophanium Compounds with Intraannular Substituents The synthesis of [3.3]dithiapyranophanone 6 and 11 is accomplished by use of the two-components-dilution-principle. Pyrolysis of their bis(sulfones) 7 and 12 gives the [2.2]pyranophanones 8 , 9 and 13 . Under preservation of conformation the intraannular carbonyl-function is used for the synthesis of methylpyranophanoles 14 , 16 and 17 . The synthesis of pyrylophanium compounds 15 and 18 is possible by elimination in trifluoroacetic acid. 6 exhibits anti-conformation within its crystal-structure and like 7 reveals temperature-dependent behavior in solution. Using 6 as an example, a combination of ¹³C-NMR-spectroscopy, forcefield-calculation and computer-simulation is applied for the first time to give evidence for molecular-dynamic processes of cyclophanes. 8 and 9 are the syn- and anti-conformers of the desired product, as shown by X-ray structural analysis. 13 reveals anti-conformation within its crystal structure as well as in solution. The conformational analysis of other new phanes described here is based on the ¹H-NMR-spectra of these pyrolysis products. As expected the intraannular substituents of Pyrylophanium-lons 15 and 18 show the characteristic upfield-shift within their ¹H-NMR-spectra.