bluuebunny/crossref_metadata_2025 huggingface dataset:
Diels‐Alder‐Reaktionen. VII. Über die Isomerisierung von 2‐Vinylbicyclo[2,2,1]hepten‐(5)
Authors: Duschek Ch. , Jentzsch R. , Kasper H. , Pritzkow W. , Schmidt H. , Zimmermann G.
Published: December 2004

Die Isomerisierung von exo/endo‐2‐Vinylbicyclo[2,2,1]hepten‐(5) in Gegenwart von Na/Al2O3führt schnell zur Einstellung des thermodynamischen Gleichgewichtes zwischen exo‐ und endo‐2‐Vinylbicyclo[2,2,1]hepten‐(5) und cis‐ und trans‐2‐Äthyliden‐bicyclo[2,2,1]‐hepten‐(5). Wesentlich langsamer wird Vinylnortricyclen gebildet, das sich bis zu einer Gleichgewichts‐konzentration von etwa 75% bei 60°C anreichert. Die Temperaturabhängigkeit der Isomerisierungs‐gleichgewichtskonstanten gestattet die Berechnung der Isomerisierungsenthalpien und ‐entropien.
d‐NMR‐Untersuchung der behinderten Rotation am ‐Bindungsinkrement. III. N‐substituierte Carbamid‐ und Thiocarbamidsäure‐O‐äthylester
Authors: Kleinpeter E. , Widera R. , Mühlstädt M.
Published: December 2004

Die NMR‐Spektren einer Reihe N‐substituierter Carbamid‐ und Thiocarbamidsäure‐O‐äthylester zeigen für die einzelnen Protonengruppen bei tiefer Temperatur jeweils zwei Signale. Diese werden der syn‐ und der anti‐Form mit Hilfe von Eu(fod)3‐Verschiebungsversuchen zugeordnet. Die dynamischen NMR‐Parameter der behinderten Rotation werden bestimmt und diefreien Aktivierungsenthalpien ΔG≠ berechnet. Die Ergebnisse werden hinsichtlich Doppelbindungsbildungstendenz des Heteroatoms und sterischen bzw. konjugativen Effekten der Substituenten diskutiert.
1,3‐Dicyclohexyl‐2,4‐bis‐(cyclohexylimino)‐1,3‐diazetidin – ein Nebenprodukt bei Peptidsynthesen mit Dicyclohexylcarbodiimid sowie 1‐Hydroxybenzotriazol als Zusatzkomponente
Authors: Jakubke H.‐D. , Klessen Ch.
Published: December 2004

In einer Nebenreaktion dimerisiert Dicyclohexylcarbodiimid unter Kupplungsbedingungen und besonders in Gegenwart von 1‐Hydroxybenzotriazol unter Bildung des 1,3‐Dicyclohexyl‐2,4‐bis‐(cyclohexylimino)‐1,3‐diazetidin 6. Die Struktur von 6 konnte durch spektroskopische und chemische Methoden sichergestellt werden.
β‐Thiocyanatovinylcarbonylverbindungen. IV. Darstellung und Reaktionen der 2‐Thiocyanatomethylen‐cycloalkanone‐(1)
Authors: Schulze B. , Herre S. , Brämer R. , Laux C. , Mühlstädt M.
Published: December 2004

2‐Thiocyanatomethylen‐cycloalkanone‐(1) 2 wurden aus den entsprechenden 2‐Chlormethylen‐cycloalkanonen‐(1) 1 dargestellt. Bei der Umsetzung mit substituierten Phenylhydrazonen isolierten wir 2,4‐Dinitrophenylhydrazone (4b, 4c und 4e) bzw. 1,2,3‐Thiadiaziniumperchlorate (5a, 5a′) sowie substituierte Pyrazole (7e, 7f). Die Reaktion von 2 mit flüssigem Ammoniak führte sowohl zu Isothiazolen (8a, 8b) als auch Bis‐(2‐acyl‐vinyl)‐sulfiden (9c, 9f).
Organische Phosphorverbindungen. VIII. Zur Solvolyse von Desmethyltrichlorphon (2,2,2‐Trichlor‐1‐hydroxy‐äthanphosphonsäuremonomethylester)
Authors: Schneider Peter , Fischer Gerhard W.
Published: December 2004

Desmethyltrichlorphon 3, ein in vivo entstehender Metabolit des Insektizides Trichlorphon 1, unterliegt in wäßriger Lösung einer Fragmentierung zu Monomethylphosphat und Dichloracetaldehyd und nicht – wie bisher vermutet – einer der Trichlorphon‐DDVP‐Umlagerung analogen Reaktion zum Desmethyl‐DDVP 4 und dessen nachfolgender Spaltung. In gleicher Weise fragmentieren die Desmethylverbindungen anderer Wirkstoffe vom Trichlorphon‐Typ. Parallel zur Fragmentierung erfährt 3 eine HCl‐Eliminierung zum Hydrat 19 des 2,2‐Dichlor‐1‐oxo‐äthan‐phosphonsäuremonomethylesters.
Diels‐Alder Reactions with Some N‐Substituted Maleimides
Authors: Khattab Samir A. , Khalifa Mohamed A. , Mahgoub Safaa A.
Published: December 2004

A series of endo‐carbonyl‐1,2‐dihydro‐(3,4,5,6‐tetraphenyl)‐N‐substituted phthalimides (5a–e) has been synthesized by the Diels‐Alder reaction of tetracyclone (2) with some N‐substituted maleimides (1a–e). Decarbonylation of the adducts 5a, b afforded the dihydrophthalimides 6a, b. The dihydro adducts 7a, b and 8a, b were obtained when phencyclone (3) and 2,3‐dimethylfurane (4) were allowed to react with maleimides 1a, b. Dehydrogenation of the dihydro adducts 5a, b, 6a, b, 7a, b, 8a, b yielded the adducts 9a, b, 10a, b, 11a, b, 12a, b, respectively. The dihydro adducts 6a, b, in contrast to the dihydro adducts 7a, b, reacted further with one molecule of a dienophile to provide the dihydro adducts 14a, b, 15a, b and 16a, b. The dihydro adducts 16a, b, were also obtained in one step when one molecule of 2 was allowed to react with two molecules of each of the N‐substituted maleimides 1a, b.
NMR‐Untersuchungen an Dicyclopentadienderivaten. VI. Shifteffekte von Substituenten unterschiedlicher Elektronegativität auf 13C‐chemische Verschiebungen
Authors: Kleinpeter E. , Borsdorf R.
Published: December 2004

Die Veränderungen der 13C‐chemischen Verschiebungen in einer Reihe monosubstituierter Cyclohexane und (exo)‐10‐substituierter Tetrahydro‐exo‐dicyclopentadien‐Derivate werden für Substituenten unterschiedlicher Elektronegativität bestimmt und die Größe der Substituentenverschiebungen Δδ auf die α‐, β‐ und γ‐ständigen C‐Atome diskutiert.
Untersuchungen zum Einfluß der Polymermatrix auf die thermische Rückreaktion von photochromen 2,4‐Dinitrobenzylpyridinen
Authors: Klemm D. , Klemm E. , Schüler K. , Hörhold H.‐H.
Published: December 2004

In fester Lösung in Polymeren (Polymethylmethacrylat, Polyäthylacrylat und Polystyrol) wird die Kinetik der thermischen Rückreaktion der Farbformen der photochromen 2‐(2′,4′‐Dinitrobenzyl)‐pyridine 1–3 unterhalb Tg durch ein Zeitgesetz 2. Ordnung, oberhalb Tg (in Polyäthylacrylat) durch ein Zeitgesetz 1. Ordnung beschrieben. Die Lebensdauer der Farbform ist von der Konstitution des Polymeren abhängig und ist am größten in polaren Polymeren hoher Molmasse. Diese Ergebnisse und die ΔS≠ ‐ und ΔH≠ ‐ Werte werden unter Anwendung des Begriffes der Reaktionshöhlung auf die festen Lösungen diskutiert.
Folgeprodukte halogenierter Aldehyde. XIII. [1] Eine Neue Synthese für O, O‐Dialkyl‐O‐polyhalogenalkyl‐thionophosphorsäureester
Authors: Schnell M. , Erfurt G. , Zinner H.
Published: December 2004

O‐Polyhalogenalkyl‐thionophosphorsäureester‐dichloride 2 erhält man durch Behandeln von Polyhalogenalkoxy‐phosphor‐tetrachloriden 1 mit Schwefelwasserstoff. Die Umsetzungen von 2 mit Alkoholen führen zu den O, O‐Dialkyl‐O‐polyhalogenalkyl‐thionophosphor‐säureestern 4.
Stereochemische Untersuchungen heterocyclischer Verbindungen. III. [1] NMR‐Spektroskopische Untersuchungen von 1‐Dialkylamino‐1H‐1,2,4,6‐thia(IV)triazinen
Authors: Michalik M. , Fischer E. , Rembarz G. , Voss G. , Storek W.
Published: December 2004

NMR‐Spektroskopische Untersuchungen verschiedenartig substituierter 1‐Dialkylamino‐1H‐1,2,4,6‐thia(IV)‐triazine zeigen, daß diese Systeme nicht eben gebaut sind. Die Ergebnisse deuten darauf hin, daß im allgemeinen weder die Rotation um die exocyclische S–N‐Bindung noch die Inversion am exocyclischen Stickstoff behindert sind.
Anionen‐Massenspektroskopie von Naturstoffen. VII. Vergleichende Anionen‐kationenmassenspektroskopische Untersuchungen von Cumarin‐Derivaten
Authors: Voigt D. , Schmidt J. , Schreiber K. , Elgamal M. H. A. , El‐Bay F. K.
Published: December 2004

Die Elektronenanlagerungs‐Massenspektren (2–4 eV) von einigen einfachen Cumarinen und Furanocumarinen sind im Vergleich zu ihren entsprechenden Kationenmassenspektren untersucht worden. Die Möglichkeit der Unterscheidung einiger Isomerenpaare wird diskutiert.
Untersuchungen über die Knüpfung der Arg‐Arg‐Bindung unter Verwendung verschiedener Kupplungsmethoden
Authors: Neubert K. , Jakubke H.‐D.
Published: December 2004

Studies on the Formation of the Arg‐Arg Bond Using Different Coupling Methods

The protected peptide Boc‐Arg(NO2)‐Arg(NO2)‐Glu(OBzl)‐Ala‐OBzl, prepared by condensation of Boc‐Arg(NO2) with Arg(NO2)‐Glu(OBzl)‐Ala‐OBzl, was synthesized by ten different coupling methods. On the basis of the yields obtained and the purity of the product the coupling methods were compared concerning their efficiency on forming the Arg‐Arg bond. The best results were obtained using the mixed anhydride method and the pentafluorophenyl ester procedure, respectively.
Darstellung von Isocyanatderivaten der aliphatischen Diäther
Authors: Lesiak T. , Maciejewski L.
Published: December 2004

On the Preparation of Isocyanatoderivatives of Aliphatic Diethers

A method for the preparation of some isocyanates of aliphatic diethers of the general formula: CH3(NCO)O[CH2]nOCH(NCO)CH32a–e, where n = 1–5 has been reported. The syntheses conditions, properties, as well as the conversion of the obtained diisocyanates into the new urea derivatives were described.
Reaktionen mit Cyclobutendionen. LII. Reaktionen von 4‐Hydroxy‐3‐phenyl‐cyclobut‐(3)‐en‐onen‐(1) mit Arylhydrazinen
Authors: Ried Walter , Knorr Harald , Oremek Gerilard
Published: December 2004

Reactions of Cyclobutendiones. LII. Reaction of 4‐Hydroxy‐3‐phenyl‐3‐cyclobuten‐1‐ones with Arylhydrazines

In the reaction of hydroxycyclobutenones of the typ 1–4 with arylhydrazines 5 an unexpected reaction behaviour is found. The major products are hydrazones of different structure, the well known hydroxy‐cyclopropane‐carboxylicacid hydrazines 6 [1] are byproducts. The direction of the reaction depends on the substituents X, on the different substituted arylhydrazines and the solvents.
Eine einfache Berechnungsmethode zur Abschätzung des induktiven Effekts verschiedenartiger komplexer Substituenten
Authors: Draffehn Joachim , Ponsold Kurt
Published: December 2004

A Simple Calculation Method for the Estimation of the Inductive Effect of Different Substituents

A new method without great mathematical operations for the estimation of the inductive effect of any substituents is described. The starting values are the electronegativities and the bond lengths of the atoms of the corresponding substituent.

The IDvalues, received by this method show a good correlation with the known electronic parameters (𝔉, σ′, σ*, σIand σ) and with the velocity constants and equilibrium constants of chemical reactions, respectively.
Zur Rolle von EDA‐Komplexen bei kationischen Polymerisationen. IV. Untersuchungen an Modellsystemen in Lösung
Authors: Heublein G. , Schubert G. , Hallpap P.
Published: December 2004

On the Role of Charge‐Transfer Complexes in Cationic Polymerization. IV. Investigation of Model Systems in Solution

For the purpose of modelling the influence of donors on the cationic polymerization the complex formation between triphenylmethyl salts of the type (p‐RC6H4)3C+MtX and aromatic π‐and n‐donors was investigated. The position of the charge‐transfer bands, the equilibrium constants as well as the enthalpies and entropies of complex formation were correlated with the acceptor strength of the cations resp. the basicity of the donors. The complex formation equilibrium was found to be strongly influenced not only by electronic but also steric effects. Strong π‐donors like hexamethylbenzene and anthracene as well as n‐donors like dialkylethers show a deviating behaviour.
Synthese von nitro‐ und aminosubstituierten Thiobenzamiden durch Thiolierungsreaktionen mit elementarem Schwefel unter milden Bedingungen
Authors: Mayer R. , Viola H. , Reichert J. , Krause W.
Published: December 2004

Synthesis of Nitro‐ and Amino‐Substituted Thiobenzamides by Thiolation Reactions with Elemental Sulfur at Mild Conditions

The Synthesis of thiobenzamides2–7by basecatalyzed thiolation of nitro‐benzyl‐halides (type1), 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 (type1) with elemental sulfur and amines occuring at low temperatures to give2–4leads via structures of the type11,15and16.
Zur Radikalischen Copolymerisation ungesättigter Isocyanate mit Vinylchlorid
Authors: Höring Siegfried , Kleine Dieter , Ulbricht Joachim
Published: December 2004

On the Free Radical Copolymerization of Unsaturated Isocyanates with Vinylchloride

The free radical copolymerization of vinyl‐, isopropenyl‐ and p‐vinyl‐phenylisocyanate with vinylchloride in mass and tetrahydrofurane solution at 50°C is investigated. The incorporation of the isocyanate monomers in the copolymers is favoured. These monomers effect a great decrease of the rate of copolymerization and a crosslinking of the formed homo‐ and copolymers, whose extent depends on the kind and the quantity of the incorporated monomers. The crosslinking is caused by the forming of isocyanurate units.
Reaktionen von β‐Chlorvinylaldehyden. IV [1]. Synthesen von 2‐Formylmethylen‐2H‐1‐benzopyranen und Benzopyrylocyaninfarbstoffen aus β‐Chlorvinylaldehyden
Authors: Weissenfels Manfred , Hense [2] Hans‐Jörg
Published: December 2004

Reactions of β‐Chlorovinylaldehydes. IV. Syntheses of 2‐Formylmethylene‐2H‐1‐benzopyranes and Benzopyrylocyaninedyes from β‐Chlorovinylaldehydes

α‐Alkyl‐β‐chlorocrotonaldehydes react with salicylaldehyde in methanolic solution of potassium hydroxide forming 2‐formyl‐methylene‐2H‐1‐benzopyranes 1. The corresponding benzopyryliumsalts 2 which are easily available from 1 and strong acids, exist in the enolic form. They react at room temperature in alcoholic solution with elimination of ethyl formiate, yielding dark blue compounds which were identified as 2,2′‐benzopyrylotrimethincyanindyes 3. The structure of 3 has been elucidated by means of 1H‐n.m.r.‐spectra.
Folgeprodukte halogenierter Aldehyde. XIV [1]. Synthesen mit 1,2,2,2‐Tetrachlorethylisocyanat
Authors: Zinner H. , Rosenthal U. , Kruse H.‐P. , Rosenthal S. , Schnell M.
Published: December 2004

Derivatives of Halogenated Aldehydes. XIV. Reactions of 1,2,2,2‐Tetrachloroethyl Isocyanate

1,2,2,2‐Tetrachloroethyl isocyanate 2 reacts with alcohols or phenols to form the N‐tetrachloroethyl‐O‐alkyl(aryl) urethanes 3–6. With thioalcohols and thiophenols the corresponding thiourethanes 11–12 are obtained. In these compounds the chlorine in position 1 can be substituted by treatment with a nucleophilic compound in the presence of a base by way of an elimination addition mechanism. In these reactions the compounds 7–10 and 13–14 are formed. Amines attack 2 at both active centres to give the substituted ureas 15–18. Diphenyl amine, some carboxylic acid amides and benzazoles, however, react only with the isocyanate group to form the compounds 19–25. Reactions of 2‐amino‐benzazoles, 2‐amino‐pyridine and amidines with 2 yield the heterocyclic compounds 26–31.
Synthese des N‐terminal um 3 Positionen verkürzten Analogen der Rinderinsulin‐B‐Kette B 4–30 (Ala 4) in geschützter Form
Authors: Losse Günter , Stange Hans
Published: December 2004

Synthesis of the N‐terminal by 3 Positions Shortened Analogue of the Bovine Insulin B Chain B 4–30 (Ala 4) in Protected Form

Starting with the pentapeptide acid Z‐Ala‐His(Trt)‐Leu‐Cys(SEt)‐Gly‐OH and the deblocked dokosapeptide derivate H‐9‐30‐OBzl of our previously reported insulin‐B‐chain synthesis the shortened, in position 4 Ala substituted analogue B 4–30 in protected form was obtained.
Spektroskopie und Photochemie indigoider Verbindungen. V. Quantenchemische Berechnungen zum unterschiedlichen UV/S‐Spektralverhalten der trans‐ und cis‐Isomeren thioindigoider Verbindungen
Authors: Sühnel J. , Gustav K.
Published: December 2004

Spectroscopy and Photochemistry of Indigoid Compounds. V. Quantum Chemical Calculations on the Different UV/VIS Spectral Behaviour of trans‐ and cis‐Isomers of Thioindigoid Compounds

The concept of non‐bonding S…O‐interaction [3] has been proved for some thioindigoid compounds. The different spectral behaviour of trans‐ and cis‐isomers with regard to the long wave absorption band is mainly dependent on the number of S…O‐structural units and on the S…O‐distance. As compared to a coplanar structure twisting about the central double bond can result both in an increasing and a decreasing spectral shift.
Synthese von 6‐Ethyl‐7‐aryloxy(thio)methyl‐4‐hydroxychinolin‐3‐carbonsäure‐ethylestern
Authors: Schrötter E. , Raddatz A. , Herudek D.
Published: December 2004

Synthesis of 6‐Ethyl‐7‐aryloxy(thio)methyl‐4‐hydroxy‐quinoline‐3‐carboxylic Esters

By etherification of phenoles and thiocresol with 2‐ethyl‐5‐nitrobenzyl chloride 2 to 1‐ethyl‐2‐aryloxy(thio)methyl‐4‐nitrobenzenes 3, reduction of 3 to the corresponding amino compounds 4, condensation of 1‐ethyl‐4‐amino‐2‐aryloxy(thio)methyl‐benzenes 4 with ethoxymethylen‐malonic ester to substituted aminomethylenmalonic esters 5 and thermal cyclization potential coccidiostatic 6‐ethyl‐7‐aryloxy(thio)methyl‐4‐hydroxyquinoline‐3‐carboxylic esters 6 have been synthesized. The structure of substituted quinolines was examined by n.m.r.
3‐Amino‐4‐cyanpyridazine durch Cyclisierung von Nitrilen
Authors: Gewald K. , Oelsner J.
Published: December 2004

3‐Amino‐4‐cyano‐pyridazines by Cyclization of Nitriles

The reaction of arylglyoxale hydrazones or benzilhydrazone with malononitrile yields the 3‐amino‐4‐cyano‐pyridazines2which may be converted into substituted 4‐amino‐pyriimido [4,5‐c]pyridazine3and 4‐amino‐isothiazolo[3, 4‐c]pyridazines4. From ω‐hydrazino‐acetophenone and malononitrile the 1,2‐diaminopyrrole derivative6is formed.
Mehrfunktionelle N‐Tenside. I. Nucleophile Substitutionen an Bischlornitrosoverbindungen 2. Reaktionen mit Thioharnstoff, substituierten Thioharnstoffen, Salzen und Estern von Dithiocarbaminsäuren und Mercaptoheterocyclen [1]
Authors: Beger J. , Thielemann C. , Thong P. D.
Published: December 2004

Polyfunctionalized N‐Tensides. I. Nucleophilic Substitutions with Bischloronitroso Compounds. 2. Reactions with Thiourea, Substituted Thioureas, Salts and Esters of Dithiocarbamic Acid and Mercaptoheterocyclic Compounds

Reaction of bischloronitroso compounds 1 with thiourea and substituted thioureas gives 2‐aminothiazoles and 3‐alkyl‐2‐iminothiazolines‐(4). Ammoniumdithiocarbamate formes 4‐thiazolinethiones‐(2), and esters of the dithiocarbamic acids give 2‐alkylmercaptothiazoles. N‐substituted salts of dithiocarbamic acid and mercaptoheterocyclics react in boiling ethanol to form S‐(β‐oximinoalkyl)‐dithiocarbamates 8 and in some cases 4‐thiazolinthiones‐(2) 9.
Synthese von Heterocyclen durch C–C‐Knüpfung. III. Heterocyclensynthesen durch intramolekulare En‐Reaktion
Authors: Schmitz Ernst , Heuck Uwe , Preuschhof Helmut
Published: December 2004

Synthesis of Heterocyclic Compounds by C–C‐bond Closure. III. Syntheses of Heterocyclic Compounds by Intramolecular En‐reaction

Cyclohexenyl‐acrylamides 1, bearing an alkyl or phenyl group at nitrogen, undergo cyclization to hexahydroindolones 2 on heating above 200°. The reaction follows the pattern of an intramolecular En‐reaction. Methacrylic acid, crotonic acid, fumaric acid or maleic acid may be part of the starting molecule in place of acrylic acid; cyclopentenyl‐amides may be used in place of cyclohexenyl‐amides. Pyrrolidone‐3‐acetic acids 16 undergo rearrangement to piperidone‐4‐carboxylic acids 17 on heating in the presence of strong alkali.
Desaktivierungsverhalten von Arenen und Heteroarenen. XVII. Löschung der Fluoreszenz von Kationen durch Anionen
Authors: Bendig JÜRgen , Kreysig Dieter , Gebert Horst , Regenstein Wolfgang
Published: December 2004

Deactivation Behaviour of Arenes and Heteroarenes. XVII. Fluorescence Quenching of Cations by Anions

Fluorescence quenching, caused by cation‐anion interaction in the excited state, was investigated for the combinations of 13 acridinium and acridizinium ions (fluorophors) and chloride, bromide and iodide (quenchers). The obtained dependence of rate constants of dynamic quenching process on the acceptor properties of cations in the case of chloride is interpreted by the model of electron transfer in the encounter state. The resulting limit‐rate constants of quenching are greater than those of diffusion of neutral molecules, caused by the Coulomb‐interaction between cation and anion.
Cyclisierungsreaktionen von 1‐[2‐Amino‐1‐cyan‐2‐thio‐]ethylen‐pyridiniumbetainen
Authors: Fischer E. , Rembarz G. , Wollin K.‐M.
Published: December 2004

Cyclization Reactions of 1‐[2‐amino‐1‐cyano‐2‐thio‐]ethenepyridinium Ylides

1‐[2‐Amino‐1‐cyano‐2‐thio‐]ethene‐pyridinium ylides 1 can be alkylated with methyliodide or α‐haloesters and α‐haloketones, respectively, to form 1‐[2‐alkyl(aryl)amino‐1‐cyano‐2‐methylthio‐ethene‐1]pyridinium iodides 2a‐–e or 1‐[2‐alkyl(aryl)‐amino‐1‐cyano‐2‐alkoxy(aryl)‐carbonylmethylthio‐ethene‐1] pyridinium salts 3a–f. With the exception of 3a–b the compounds 3 or 1 react with haloketones to yield 1‐[4‐amino‐2‐alkyl‐(aryl)amino‐5‐benzoyl‐thiene‐3]pyridinium salts 4a–m or 3‐alkyl‐4‐aryl‐2‐(1‐cyano‐1‐pyridinium)methylene‐Δ4‐thiazoline salts 5a–f.
Über heteroorganische Verbindungen. LII. Thiophosphonsäureamide und ihre Derivate
Authors: Almasi L. , Feneşan I. , Biró V.
Published: December 2004

Heteroorganic Substances LII. Amidothiophosphonic Acids and Their Derivatives

The synthesis of amidocyclohexanthiophosphonic‐ and amidophenylthiophosphonic‐acids is described. The structure are determined by means of spectroscopical and chemical methods. These compounds 1–3 have not a bipolar structure, as assumed formerly [2] in the case of compound 3, but exist in a thiono‐thiolo tautomeric equilibrium, which lies far on the site of the thiono‐form. The alkylation of 1–3 with diazomethan gives S‐methyl‐, respectively O‐methyl‐derivatives. The alkylation of the ambident anions with CH3I gives only S‐methylderivatives, whereas the acylation with CH3COCl occurs at the oxygen atom.
Chemische Synthese der Oligonucleotide dpG‐A‐T‐A‐T‐C, dpG‐A‐T‐C‐T‐T‐T‐T und dpT‐T‐T‐C‐A‐T‐C‐A‐T
Authors: Weiss R. , Birch‐Hirschfeld E. , Reinert H.
Published: December 2004

Chemical Synthesis of the Oligonucleotides dpG‐A‐T‐A‐T‐C, dpG‐A‐T‐C‐T‐T‐T‐T and dpT‐T‐T‐C‐A‐T‐C‐A‐T

For studies of some sequence dependent structural factors the oligonucleotides dpG‐A‐T‐A‐T‐C, dpG‐A‐T‐C‐T‐T‐T‐T and dpT‐T‐T‐C‐A‐T‐C‐A‐T were required. Their chemical synthesis is reported according to the diester method.
Modellrechnungen zum Gegenioneneinfluß auf die kationische Polymerisation; Der Zerfall der gemischten Halogenoantimonate SbCl5Br− und SbClBr
Authors: Zwanziger Heinz , Reinhold Joachim , Hallpap Peter , Heublein Günther
Published: December 2004

Model Calculations on the Counterion Effect in the Cationic Polymerization; Decay of the Mixed Halogenoantimonates SbCl5Br− and SbClBr

The decay of the halogenoantimonates SbCl5Br− and SbClBr according to SbCl5Br− → SbCl5 + Br− resp. SbCl4Br + Cl− and SbClBr → SbBr5 + Cl− resp. SbClBr4 + Br− has been investigated by the quantum‐chemical CNDO/2 method including geometry optimization. The calculations show that the dissociation of the SbCl bond needs more energy (7,8 kcal/mol) than the dissociation of the SbBr bond.

Dissociation of the complex anions is facilitated with increasing Br content.
Stereochemische Untersuchungen mit der 13C‐NMR‐Spektroskopie. V. Methyl‐ und tert.‐butylsubstituierte Cyclohexane
Authors: Jancke H. , Werner H.
Published: December 2004

Stereochemical Investigations by Means of 13C‐N.M.R.‐Spectroscopy. V. Methyl‐ and tert.‐Butyl‐substituted Cyclohexanes

The 13‐chemical shifts of some cyclohexanes with methyl and tert. butyl as substituents in configurational different positions are discussed. The substituent effects of the methyl and t‐butyl groups, respectively, on the C‐atoms of the ring are different and can be explained with the aid of long range (γ and δ) steric interactions. It is shown, that in all investigated compounds a twisted conformation of the ring is prefered instead of an axial arrangement of a t‐butyl group.
Cyansäureester. 29. Benzoxazolin‐thion‐N‐imidsäureester und ihre Folgereaktionen
Authors: Martin D. , Wenzel A.
Published: December 2004

Cyanic Acid Esters. 29. Benzoxazoline‐thione‐N‐imid Esters and Their Consecutive Reactions

Oxazoline‐thiones‐(2) and aryl cyanates react to form the corresponding isoureas 4. These compounds are remarkably stable against electrophilic reagents. The aminolysis of 4 proceeds two pathways: a transformation of the imid ester residue to the amin and a ring opening reaction by attack of the amin to the CS‐bond. The hydrazinolysis causes a ring‐transformation of the oxazoline‐ to the 1,3,4‐triazole system.
Zur Reaktion der N‐Sulfinylamine mit Isocyaniden und die Synthese von 2,5‐Diaryl‐3,4‐diarylimino‐1,2,5‐thiadiazolidin‐S‐oxiden
Authors: Beckert R. , Mayer R.
Published: December 2004

The Reaction of N‐Sulfinylamines with Isocyanides and Synthesis of 2,5‐Diaryl‐3,4‐diarylimino‐1,2,5‐thiadiazolidin‐S‐oxides

N‐Sulfinylamines 1 react with isocyanides 2 to give isocyanates 3, isothiocyanates 6, and especially 2,5‐diaryl‐3,4‐diarylimino‐1,2,5‐thiadiazolidin‐S‐oxides 7.

This new heterocyclic ring system 7 can also be synthesized in high yields by a cyclization reaction of tetraarylated oxalic amidines 9 with thionyl chloride.

The acid catalyzed hydrolysis of the heterocyclic compounds 7 leads to oxalic anilides 8, the hydrolysis with alkali forms amidines 9. The amidine 9a reacts with N‐sulfinyl‐p‐toluenesulfonamide 11 to give an open chained adduct 12.
Sauer katalysierter Disulfidaustausch von S‐Alkylthio‐cystein‐Derivaten
Authors: Kunzek Herbert , Haupt Renate , Huschert Günter
Published: December 2004

Proton‐Catalyzed Disulfide Exchange of S‐Alkylthio Cysteine Derivatives

Although N‐unprotected S‐alkylthio cysteine derivatives are relatively stable in acid solutions, N‐acylsubstituted and N‐urethane protected S‐alkylthio cysteines react easily by disulfide exchange. As a rule the frequently used tert.‐butyloxycarbonyl amino protecting group, present in ethylthio cysteine derivatives can′t be removed selectively without disulfide cleavage, whilst the 2‐(p‐biphenylyl)isopropyloxycarbonyl and the 2‐phenyl‐isopropyloxycarbonyl amino protecting groups are removable without any structure change of the alkylthio thiol protecting groups. It is advisable to realize this acid demasking of the amino groups by means of weak deblocking reagents. Comperative experiments in acid solution prove S‐tert.‐butylthio group to be the most stable protecting function, whilst isopropylthio cysteine derivatives are more stable than the corresponding S‐ethylthio compounds. All these results and experiments with addition of different thiols as well as u.v.‐spectroscopic investigations indicate, that the observed acid catalyzed disulfide exchange proceeds via a carbonyl neighbouring group effect and formation of thiazolidinium and thiazolinium intermediates, respectively.
Photokatalytische Systeme. XXXIV. Über die Photoreduktion von Carboxylato(cuproin)kupfer(II)‐Chelaten in Alkoholen
Authors: Rehorek D. , Jarzynowski T. , Stasicka Z.
Published: December 2004

Photocatalytic Systems. XXXIV. On the Photoreduction of Carboxylato(cuproine) Copper (II) Chelates in Alcohols

In contrast to the behaviour in nonpolar aprotic solcents, the photolysis of cuproine copper(II) chelates of the type Cu(NN) (RCOO)2 (R  CH3, C(CH3)3; NN = sterically hindered heterocyclic 1, 2‐diimine ligand) in alcohols does not lead to formation of free radicals.

A two‐step mechanism with non‐radicalic intermediates is derived from e.s.r. spin trapping and microsecond flash photolysis experiments.
Azoperoxide. VII. Thermolyse von α‐Alkylazo‐alkylhydroperoxiden
Authors: Schulz Manfred , Missol Udo
Published: December 2004

Azoperoxides. VII. Thermolysis of α‐Alkylazoalkylhydroperoxides

The thermal decomposition of 1‐methylazo‐1‐hydroperoxycyclohexane 1 and 1‐tert.‐butylazo‐1‐hydroperoxycyclohexane 2 was studied in ethylbenzene and in the case of 2 also in other solvents. Decomposition products and decomposition rates of the azo and the peroxy groups were selectively estimated. The title compounds decompose faster than the analogous azo compounds and alkylhydroperoxides. A induced homolysis of both initiator groups is proposed; the compounds are not „bifunctional initiators”︁.
Der Substituenteneinfluß auf IR‐Spektrenparameter von 4′‐phenylsubstituierten (E)‐Styryl‐methyl‐sulfonen
Authors: Siegmund Manfred , Wegener Wolfgang , Schleinitz Klaus‐Dieter
Published: December 2004

The Influence of Substituents on the I.R. Spectral Parameters of 4′‐Phenylsubstituted (E)‐Styryl‐methyl‐sulphones

The positions and integrated intensities of the bands corresponding to characteristic vibrations of eight 4′‐phenylsubstituted (E)‐styryl‐methyl‐sulphones were determined and correlated with substituent constants. The results demonstrate a linear dependence of the wavenumbers ofvSO2andVCC vibrations, respectively, with the electrophilic substituent constants σ. Otherwise the square roots of the integrated intensities A1/2(vsso2) and σgave no linear correlation.

The influence of the substituents on the i.r. spectral parameters is discussed and compared with π‐bond orders and π‐electron densities. These magnitudes reflect qualitatively the behaviour of i.r. frequencies and intensities of selected absorption bands.
1H‐NMR‐Untersuchungen zur Identifizierung E/Z‐isomerer Vinylthiophosphate und Vinylphosphate
Authors: Preiss A. , Dietzel St. , Fedgenhäuer H. , Hesse B.
Published: December 2004

1H‐N.M.R.‐Studies on the Identification of E/Z‐isomeric Vinyl Phosphorothioates and Vinyl Phosphates

The E/Z assignment of 1, 1, 2‐tri and tetrasubstituted vinyl phosphorothioates and vinyl phosphates by 1H‐n.m.r. investigations is described. While the assignment of 1, 1, 2‐trisubstituted compounds is based on a positiv nuclear Overhauser effect which exists between ortho phenyl protons and the vinyl proton of the Z isomer, the configuration of the tetrasubstituted compounds has been determined by lanthanide induced shifts. The effect of different europium coordination in the vinyl phosphorothioates and vinyl phosphates on the paramagnetic shifts is discussed.
Zur Berechnung des HLB‐Wertes isomerer und substituierter Alkansulfonate
Authors: Sowada Rudolf
Published: December 2004

Concerning the Calculation of HLB Values of Isomeric and Substituted Alkane Sulphonates

Based on LIN's hydrophobicity index HLB values have been calculated for the isomeric dodecane sulphonates and some substituted pentadecane‐1‐sulphonates.
Zur Beschreibung der Wechselwirkung zwischen p‐substituierten Benzaldehyden und NMR‐Verschiebungsreagenzien
Authors: Piegsa U. , Radeglia R. , Doerffel K.
Published: December 2004

Investigations to the Interaction between p‐Substituted Benzaldehydes and N.M.R.‐Shift Reagences

The influence of n.m.r. shift reagents (Eu(fod)3 and Pr(fod)3) on the chemical shifts of p‐dimethylaminobenzaldehyde has been investigated at 13C and 1H‐n.m.r. spectroscopy. The induced shifts of the protons are quantitatively explained on the basis of pseudocontact interaction. In 13C‐n.m.r. spectra significant contact interactions have also been noted. The 13C induced shifts have been separated into pseudocontact and contact contributions by two different methods. Calculations of relative equilibrium constants in mixtures have been carried out for p‐dimethylaminobenzaldehyde, p‐nitrobenzaldehyde, anisaldehyde and benzaldehyde. The relative equilibrium constants show a good correlation with the Hammett substituent constants.
Chemistry and application of organic isocyanates. III. Reaction of Poly(oxyethylene)sucrose with n‐Octadecyl or Stearoyl Isocyanate
Authors: Lesiak T. , Iwaszkiewicz‐Nowak J. , Spychaj‐Fabisiak E.
Published: December 2004

Chemie und Anwendung von organischen Isocyanaten. III. Umsetzungen von Poly(oxethylen)saccharose mit n‐Octadecyl‐ und Stearoyl‐isocyanaten

Die Synthese von neuen N‐n‐Octadecyl‐ und N‐Stearoylcarbaminsäureestern der Poly(oxethylen)saccharose und die Schaumkraft der erhaltenen Verbindungen werden beschrieben. Oberflächenspannungen wäßriger Lösungen aller gewonnenen N‐substituierten Urethane werden in Abhängigkeit von der Konzentration untersucht und mit jenen von Na‐Dodecylsulfat und K‐Oleat verglichen.
Synthesen von β‐Fur‐2‐yl‐α‐halogenacrylonitrilen
Authors: Jähnisch K. , Seeboth H.
Published: December 2004

Syntheses of β‐Fur‐2‐yl‐α‐halogenacrylonitriles

Syntheses of β‐fur‐2‐yl‐α‐halogenacrylonitriles 2a–f by Wittig‐olefination of furfurales, Hunsdiecker‐reaction of β‐(5‐nitro‐fur‐2‐yl)‐α‐cyanoacrylic acid 3, halogenation of β‐fur‐2‐yl acrylonitriles and reaction of furfurales with β‐azido‐α‐halogen‐γ‐methoxy‐Δα,β‐crotonolactones 9 are described.
Zur Berechnung effektiver Kohlenstoffzahlen für Heterogruppen enthaltende Paraffinketten Methylengruppenäquivalent‐Werte einiger Heterogruppen
Authors: Sowada Rudolf
Published: December 2004

On the Calculation of Effective Carbon Numbers for Paraffin Chains Containing Hetero Groups. Methylene Group Equivalent Values for Some Hetero Groups

Effective carbon numbers and hydrophobicity indices for paraffin chains containing hetero groups have been calculated by means of STAUFF/KLEVENS′ equation from published cM data for adequately substituted alkylbenzene sulphonates and alkane sulphonates resp. Methylene group equivalent values ME are given for some hetero groups. Via ME values critical micelle concentrations for alkylbenzene sulphonates and for alkane sulphonates containing hetero groups can be calculated.
Steroide. 66.1H‐NMR‐Untersuchungen. Konfigurationszuordnung 15, 16, 17‐trisubstituierter Steroide
Authors: Schönecker B. , Tresselt D. , Schubert G. , Ponsold K.
Published: December 2004

Steroids. 66.1H‐N.M.R.‐Investigations. Configurational Assignment of 15, 16, 17‐Trisubstituted Steroids

The1H‐n.m.r.‐spectra of 15, 16, 17‐trisubstituted estra‐1,3,5(10)‐trienes are discussed in view of the configurational assignment of the substituents. A reliable elucidation of their stereo‐chemistry is possible on the basis of the coupling constants J16H,17H, J15H,16Hand J14αH,15H. Additional parameters are the chemical shifts of the 15‐, 16‐, 17‐ and 18‐protons (13β‐methyl group) and the downfield shift of carbinol proton signals, caused by the reaction of hydroxyl groups with trichloroacetyl isocyanate. The chemical shifts of the 13β‐methyl group can be calculated for compounds with trans configuration from substituent increments and for the other compounds by comparison with the chemical shifts of 16, 17‐disubstituted compounds. The influence of different 16α‐substituents on the chemical shifts of 15α‐ and 17α‐protons is investigated. The downfield shifts of 15‐ and 17‐proton signals due to the addition of trichloroacetyl isocyanate to 15, 17‐diols depend on the configuration of the 16‐substituents.
Konstitution und Redoxstabilität von Kupfer(II)‐Komplexen mit substituierten Hydrazinen
Authors: Kempe G. , Bögel M. , Roewer G.
Published: December 2004

Constitution and Redox Stability of Copper(II)‐Complexes with Substituted Hydrazines

CuCl2 reacts with substituted hydrazines forming chelates of the CuIIL2Cl2 type (L = RCONHNH2, RCONHN(C6H5)2, RCONHNHCOR, H2NNHCO(CH2)nCONHNH2) which are characterized by quantitative analysis, i.r. and e.p.r. spectra. The complex polyhedron exhibits the geometry of a tetragonally distorted octahedron of C2v symmetry. The complexes undergo intramolecular redox decomposition in acetonitril forming Cu(I) species.

The rate constants increase with decreasing half wave oxydation potential and decreasing Homo energy of the hydrazine ligands, respectively.
Über die Photochromie der Fulgide. IX Untersuchungen zur Photochemie des α‐3,5‐Dimethyoxyphenyl‐δ‐δ‐dimethylfulgids
Authors: Ilge H.‐D. , Langbein H. , Reichenbächer M. , Paetzold R.
Published: December 2004

The Photochromism of Fulgides. IX. Investigations of the Photochemistry of α‐3,5‐Dimethoxyphenyl‐δ,δ‐dimethylfulgide

The mechanism of photoisomerization of α‐3,5‐dimethoxyphenyl‐δ, δ‐dimethylfulgide was investigated by means of u.v./vis‐ and fluorescence spectroscopy. The quantum yields of E‐Z isomerization and cyclisation were determined in various solvents and at different temperatures. Triplet sensitization of E‐Z isomerization by several sensitizers has been found. The thermal dark reactions of the deep coloured species were reinvestigated.
Über einige Zusammenhänge zwischen massenspektrometrischen Ionenhäufigkeiten und Moleküleigenschaften an element‐organischen Verbindungen der Gruppe IVb. Massenspektren der Trialkylhydride des Si, Ge und Sn
Authors: Hottmann K.
Published: December 2004

About Some Correlations between Mass‐spectral Abundances of Ions and Properties of Molecules on Element‐organic Compounds of IVb‐Elements

Mass Spectra of Symmetrical Trialkylhydrids of Si, Ge and Sn

The monoisotopic mass spectra of (C2H5)3ZH, (n‐C3H7)3ZH and (n‐C4H9)3ZH (Z = Si, Ge, Sn), (CH3)3SiH and (C2H5)3SiD at 70 eV are reported. The main reactions and changes in the competition behaviour with variation of central atom Z and length of alkyl‐chain are discussed in terms of physical‐organic theory of mass spectra (POT) and of QET. There are some serious discrepancies with respect to the POT. The fragmentation behaviour is in good agreement with consequences of the QET. The analogic carboniumcompounds are included in the discussion.
Aktivierungsentropien radikalischer Additionsreaktionen mittels MINDO/3‐UHF‐Rechnungen
Authors: Köhler H.‐J. , Knoll H.
Published: December 2004

Activation Entropies of Free Radical Addition Reactions via MINDO/3‐UHF‐Calculations

A MINDO/3‐UHF study on the additions of methyl radicals to acetone, formaldehyde, ethylene, and isobutene indicates that the transition state occurs later with non‐terminal C‐addition as compared to terminal C‐addition. Distinctly lower activation entropies are obtained for non‐terminal addition.
Push‐pull‐Butadiene. II [1]. Reaktionen von 2‐Aryl‐4,4‐bis(methylthio)buta‐1,3‐dien‐1,1‐dicarbonitrilen mit Malononitril und Cyanessigsäure‐ethylester
Authors: Peseke K.
Published: December 2004

Push‐pull‐Butadienes. II. Reactions of 2‐Aryl‐4,4‐bis(methylthio)‐1,3‐butadiene‐1,1‐dicarbonitriles with Malononitrile and Ethyl Cyanoacetate

2‐Aryl‐4,4‐bis(methylthio)‐1,3‐butadiene‐1,1‐dicarbonitriles 1 react with sodium salts of malononitrile or ethyl cyanoacetate 3 to give 4‐aryl‐2‐methylthio‐1,4‐pentadiene‐1,1,5,5‐tetracarbonitriles and ethyl‐4‐aryl‐1,5,5‐tricyano‐2‐methylthio‐1,4‐pentadienecarboxylates 4, respectively. Also, arylethylidenemalononitriles 5 and bis(methylthio)methylenemalononitrile or ethyl bis(methylthio)methylenecyanoacetate 6 afford 4. Substituted dihydropyridines 8 are prepared by treating 4 with aromatic amines. Compounds 4 d, e can be converted to 2‐amino‐6‐aryl‐4‐methylthio‐benzene‐1,3‐dicarbonitriles 11 a, b.
Synthese von N‐sulfinylgeschützten Aminobenzylhalogeniden und Umsetzung mit Nucleophilen
Authors: Beckert R. , Mayer R.
Published: December 2004

Synthesis of N‐Sulfinylprotected Aminobenzylhalides and Reactions with Nucleophiles

N‐Sulfinylaminotoluenes 3 react with sulfuryl chloride or N‐bromosuccinimide to give N‐sulfinylaminobenzylchlorides 4 and N‐sulfinylaminobenzylbromides 5, respectively.

o‐N‐Sulfinylaminobenzylchloride 4 a can also be synthesized by the reaction of o‐aminobenzylalcohol 6 with thionyl chloride.

Nucleophiles react with benzylhalides 4 and 5 to form aminobenzyl ethers, thioethers, and amines 7–9.

Tetrahydrochinazolinethione 11 can be formed by the reaction of 4 a or 5 a with thiocyanate ions followed by the hydrolysis of intermediate 10.
Untersuchung zur Ringöffnungspolymerisation von 2‐Phenoxymethyl‐1,4,6‐trioxa‐spiro‐[4,4]‐nonan
Authors: Klemm E. , Haase L.
Published: December 2004

Investigation of Ring‐Opening Polymerization of 2‐Phenoxymethyl‐1,4,6‐trioxa‐spiro[4,4]‐nonan

Under the conditions of a radical induced cationic ringopening‐polymerization the spiro ortho ester 1b can be polymerized with diphenyliodoniumtetrafluorborat/benzpinacol (1:1). The optimal initiator concentration is 2–2.5 mol‐% Ph2I+BF4−. The average molecular weight is 6000, Tg = −4°C. Polymerization of 1b in presence of BF3 · Et2O produced identical results. The structure of polymer 2b was indicated by its analysis as well as its infrared spectra.
Untersuchungen zur Sulfochlorierung von Paraffinen. X. Über die Anwendbarkeit additiver Inkremente bei der Auswertung der 13C‐NMR‐Spektren von Alkanmono‐ und ‐disulfochloriden und von Chloralkansulfochloriden
Authors: Radeglia R. , Schmidt‐Renner W.
Published: December 2004

Studies on Sulphochlorination of Paraffins. X. The Application of Additive Increments for the Interpretation of 13C‐N.M.R. Spectra of Alkane Mono‐ and Disulphochlorides and of Chloroalkane Sulphochlorides

Increments which consider the influence of chlorine and sulphonylchloride substituents on the 13C‐n.m.r. shifts of alkanes were calculated and discussed. The application of additive increments for the calculation of 13C‐n.m.r. chemical shifts of alkane‐1,2‐disulphonylchlorides, branched alkane monosulphonylchlorides, sulphochlorinated 1‐alkylchlorides and chlorinated 1‐alkane sulphonylchlorides is demonstrated. The limitations of the method are discussed.
Synthese und dielektrische Eigenschaften kristallin‐flüssiger alkyliminomethyl‐substituierter Benzoesäurephenylester
Authors: Weissflog W. , Möckel P. , Tschimeg Sh. , Kresse H. , Demus D.
Published: December 2004

Synthesis and Dielectric Properties of Liquid Crystalline Alkyliminomethyl‐Substituted Phenylbenzoates

The synthesis of 4‐n‐alkyliminomethyl‐phenyl‐4′‐n‐alkoxybenzoates and their mesomorphic properties are described. We have investigated the dielectric constants and the relaxation frequencies (MHz‐region) of the nematic and smectic A phases.
Zur Pyrolyse von Cycloalkenoaromaten
Authors: Günschel H. , Zimmermann G. , Lorenz R. , Ondruschka B. , Nowak S.
Published: December 2004

On the Pyrolysis of Cycloalkenoaromatics

The products of pyrolysis of tetraline (1), indane (2), 2‐methylindane (3), and tetrahydroacenaphthene (4) in mixtures of n‐paraffins were analyzed by gas chromatography. Results show that by temperatures between 700° and 800°C and residence times of about 0.2 s more than 80% of the reaction products are aromatics. The main pathway of the decomposition of 1, 2, and 4 is the dehydrogenation in direction to the corresponding complete aromatic systems or indene respectively. In the case of 3 we found less than 10% of 2‐methylindene but more than 40% of skeleton isomeres. The formation of skeleton isomeres can be explained by the concept of radical rearrangements.
Synthese von Pyrrolo[1,2‐a]chinazolinonen, Indolo[1,2‐a]chinazolinonen, Pyrrolo[1,2‐a]thieno[3,2‐e]pyrimidinonen, Benzothieno[3,2‐e]‐pyrrolo[1,2‐a]pyrimidinonen und 6H‐Cyclohepta[4,5]thieno‐[3,2‐e]pyrrolo[1,2‐a]pyrimidinonen
Authors: Süsse M. , Johne S.
Published: December 2004

A Synthesis of Pyrrolo[1,2‐a]quinazolinones, Indolo[1,2‐a]‐quinazolinones, Pyrrolo[1,2‐a]thieno[3,2‐e]pyrimidinones, Benzothieno[3,2‐e]pyrrolo[1,2‐a]pyrimidinones and 6H‐Cyclohepta[4,5]‐thieno[3,2‐e]pyrrolo[1,2‐a]pyrimidinones

α‐Cyano‐γ‐halo‐crotonnitriles (1) synthesized (e.g. via Knoevenagel reaction and by subsequent halogenation) react with primary arylamines (2) to substituted 1‐aryl‐2‐amino‐3‐cyano‐pyrroles (3). We found that the reaction yields pyrrolo[1,2‐a]quinazolin‐5‐ones (6) in a one‐pot procedure if anthranilic esters (4) and compounds of the general formula5are used. The analogous treatment with 2‐amino‐3‐ethoxy‐carbonyl‐thiophene derivatives (8) leads to pyrrolo[1,2‐a]thieno‐[3,2‐e]pyrimidin‐5‐ones, benzothieno[3,2‐e]pyrrolo[1,2‐a]pyrimidinones and 6H‐Cyclohepta[4,5]‐thieno[3,2‐e]pyrrolo[1,2‐a]pyrimidinones as thiadiazastereoid analogs9.

This reaction is suitable for the synthesis of various heterocyclic ring systems.
Mikrobielle Reduktion 2,2‐disubstituierter Cyclopentan‐1,3‐dione. Darstellung chiraler Cyclopentanderivate für die Synthese von 8‐Methyl‐prostaglandinen
Authors: Schwarz S. , Truckenbrodt G. , Meyer M. , Zepter R. , Weber Gisela , Carl Constanze , Wentzke M. , Schick H. , Welzel H.‐P.
Published: December 2004

Microbial Reduction of 2,2‐Disubstituted Cyclopentan‐1,3‐diones. Synthesis of Chiral Cyclopentane Derivatives Useful as Intermediates for 8‐Methyl Prostaglandins

The microbial reduction of the 2,2‐disubstituted cyclopentan‐1,3‐diones 3ac giving rise to the chiral compounds 2, 4b and 4c is described.

The incubation products can be used as intermediates for 8‐methyl prostaglandins.

The structures of the fermentatively formed compounds, including their chirality and optical purity have been established by comparison with authentic specimen (cp. 2) or by chemical and spectroscopic methods (cp. 4b, 4c) respectively.
1H‐ und 13C‐NMR‐chemische Verschiebungen von 5‐Ring‐Schwefel‐ und Selenheterocyclen Ein Beitrag zum Zusammenhang zwischen Elektronenstruktur und 13C‐chemischer Verschiebung von CO‐, CS‐ und CSe‐Gruppierungen
Authors: Poleschner H. , Radeglia R. , Fanghänel E.
Published: December 2004

1H‐ and 13C‐N.M.R. Chemical Shifts of 5‐Membered Sulfur and Selenium Heterocycles A Contribution about the Relation between Electronic Structure and 13C Chemical Shifts of CO, CS, and CSe Groups

The 1H‐ and 13C‐N.M.R. chemical shifts of 1,3‐dithiole‐ 1–3, 1,3‐thiaselenole‐4–6 and 1,3‐diselenole‐2‐ones, ‐thiones and ‐selones 7–9 and the 13C‐N.M.R. chemical shifts of the corresponding saturated compounds 1,3‐dithiolane‐2‐one 10, ‐thione 11 and ‐selone 12 as well as 1,3‐diselenolane‐2‐thione 13 and ‐selone 14 are submitted. The 13C chemical shifts of the ring‐carbon atoms C‐4, C‐5 and C‐2 in dependence on the endo‐ and exocyclic ring heteroatoms (O, S, Se) are demonstrated by shift increments and discussed. In the unsaturated heterocycles linear dependences are observed for (i) 1H‐ and 13C‐NMR chemical shifts of the methine fragments in 4‐position and (ii) 13C chemical shifts of CS and CSe carbons in analoguous substituted compounds. The 13C absorptions of C‐2 are shifted to lower field in the series CO, CSe, CS (analoguous substituted compounds). This observation is not to understand by variations in the δE term of the 13C chemical shift but much better by changes in the electron density distribution.

Die in den letzten Jahren zu beobachtende stürmische Entwicklung methodischer und apparativer Aspekte der NMR‐Spektroskopie schwerer Kerne ließ die 13C‐Kernresonanz zu einer Routine‐methode für die Strukturaufklärung in der organischen Chemie werden. Die 13C‐NMR‐Spektroskopie ist in dieser Hinsicht besonders leistungsfähig, da die 13C‐NMR‐chemische Verschiebung – der wichtigste Parameter dieser Methode – sehr empfindlich auf Strukturänderungen reagiert und diese Einflüsse häufig durch Inkremente beschrieben werden können. Da man bei der Signalzuordnung und Spektreninterpretation oft auf experimentelles Vergleichsmaterial angewiesen ist, kommt der Kenntnis von Zusammenhängen zwischen Molekülbau und Spektrenparametern eine allgemeine Bedeutung für die Strukturanalytik zu.
Zur Berechnung der mizellaren Aggregationszahl homologer und isomerer Alkansulfonate
Authors: Sowada Rudolf
Published: December 2004

On the Calculation of Micellar Aggregation Numbers for Homologous and Isomeric Alkane Sulphonates

Based on CHUJO's correlations the following equation is derived to calculate micellar aggregation numbers m for homologous and isomeric alkane sulphonates: log m = 0,713 + 0,085 · I · Fs · nC

It is shown that variation of the critical micelle concentration is not the only factor determining the m values of detergents. cM and m values for the unknown isomeric pentadecane sulphonates have been calculated.

Detergents with functional groups in middle positions are of great interest due to very low m values besides low cM values.
Untersuchungen über die Autoxidation verzweigter Olefine. I, Autoxidation von 2‐Methylalk‐1‐enen und 2‐Methyalk‐2‐enen
Authors: Bilas W. , Pritzkow W. , Höbold W.
Published: December 2004

Studies on the Autoxidation of Branched‐chain Olefins. I. Autoxidation of 2‐Methylalk‐1‐enes and 2‐Methylalk‐2‐enes

The products of the autoxidation of 2‐methylpent‐1‐ene, 2‐methylpent‐2‐ene, 2‐methylhex‐1‐ene, 2‐methylhex‐2‐ene, 2,4,4‐trimethylpent‐1‐ene, and 2,4,4‐trimethylpent‐2‐ene were analyzed by gas chromatography. The identification of the products corresponding to the individual peaks was possible by comparison with authentic substances or by preparative gaschromatographic separation and n.m.r.‐spectroscopy of the isolated samples. In this way not only the epoxides and the products of the oxidative cleavage of the CC‐double bond but also the allylic alcohols formed by LiAlH4‐reduction of the oxidation mixtures could be identified and analyzed. From the results the compositions of the original oxidation mixtures were calculated.