bluuebunny/crossref_metadata_2025_split huggingface dataset:
13C‐, 14N‐ und 1H‐kernresonanzspektroskopische Untersuchungen an m‐/p‐substuierten N‐Methylpyridiniumjodiden
Authors: Wehrli F. W. , Giger W. , Simon W. 
Published: December 2004

AbstractIn a series of 21 m‐/p‐substituted N‐methylpyridinium salts, N‐methyl proton, carbon‐13 and pyridinium nitrogen‐14 chemical shifts were determined by heteronuclear double resonance, and partly in the case of the 14N nucleus and the methyl protons by direct measurement. In a few compounds the quadrupole relaxation times proved to be too short for the 14N coupling to be detected. This problem was overcome by adequately rising the sample temperature. For all three nuclei a marked dependence of the chemical shifts on the nature of the substituent could be established. Increased nitrogen π‐electron density shifts the resonances towards higher fields. In the case of the 14N shieldings, this tendency is attributed to changes in the paramagnetic screening term, whereas for 13C and 1H an interpretation is given in terms of a neighbour anisotropy contribution. The latter explanation is based on the observation that the calculated carbon and hydrogen charge densities show no significant variations throughout the series. Excellent shift correlations were obtained with Hammett substituent constants when σ+‐values were used for donor substituents. A similar substituents, dependence could be observed for the direct 13CH methyl coupling constants, whose magnitude increases with decreasing nitrogen charge density.
Absolute Konfiguration von δ‐Carotin aus der Tomatenmutante Del/Del 65–3–54–5
Authors: Buchecker R. , Eugster C. H. 
Published: December 2004

Abstract(+)‐δ‐Carotene (II) isolated from a tomato mutant is shown by comparison of its circular dichroism with that of (+)‐α‐carotene to possess at C(6) the chirality of natural (+)‐α‐carotene (I) and ε‐carotene (III).
Schmelzreaktionen mit Aluminiumchlorid. 6. Mitteilung [1]. Zur kenntnis der carbazolierung von anthrimiden in aluminiumchlorid‐schmelzen
Authors: Wick A. K. 
Published: December 2004

AbstractThe behaviour of di‐(1‐anthraquinonyl)‐amine, when cyclised in pyridine‐aluminium chloride or pure aluminium chloride fusions, has been compared. The formation of blue educt complexes with aluminium chloride in the latter case has been revealed as a factor which inhibits cyclisation. The results are discussed and generalised, classifying carbazolation of anthrimides as an intramolecular Scholl‐type reaction.
Über Pterinchemie. 35. Mitteilung [1]. Herstellung von 6‐aminomethyl‐6‐methyl‐5,6,7,8‐tetrahydropterin, ein Beitrag zur frage der Existenz von parachinoid‐dihydropterinen
Authors: Viscontini M. , Frater‐Schroeder M. , Argentini M. 
Published: December 2004

AbstractDie erste Synthese eines 6, 6‐disubstituierten Tetrahydropterins, nämlich des 6‐Aminomethyl‐6‐methyl‐5, 6, 7, 8‐tetrahydropterins, wird beschrieben: Das durch Anlagerung von Blausäure an 6‐Methyl‐7, 8‐dihydropterin entstandene 6‐Cyano‐6‐methyl‐5, 6, 7, 8‐tetrahydropterin wird acetyliert, reduziert und anschliessend desacetyliert. Entgegen unserer Erwartung bildet das 6‐Aminomethyl‐6‐methyl‐tetrahydropterin bei der Oxydation durch Luftsauerstoff unter physiologischen Bedingungen kein Parachinoid‐dihydropterin, sondern wird direkt zu 6‐Methyl‐7, 8‐dihydropterin, Formaldehyd und Ammoniak abgebaut.
Zur Photochemie des Benzfurazans
Authors: Georgarakis M. , Rosenkranz H. J. , Schmid H. 
Published: December 2004

AbstractIrradiation of benzofurazan (1) in benzene solution yields the azepine derivative 3 as the main photoproduct. Addition of methanol in the dark to the irradiated benzene solution of 1 results in the isolation of 3 together with a new product, methyl‐1‐cis, 3‐cis‐N‐(4‐cyano‐buta‐1, 3‐dien‐1‐yl)‐carbamate (1‐cis, 3‐cis‐2). Irradiation of 1 in methanol solution gives a mixture of the stereoisomeric methyl N‐(4‐cyano‐buta‐1, 3‐dien‐1‐yl)‐carbamates, from which the 1‐trans, 3‐cis isomer of 2 could be isolated in pure form.The observed photoproducts are formed via the reactive intermediates a, a nitrile‐(nitrile oxide), and c, a nitrene, neither of which was isolated.
Hormon‐Rezeptor‐Beziehungen: Synthese und eigenschaften von Nε‐dansyllysin21‐adrenocorticotropin‐(1–24)‐tetrakosipepid
Authors: Schwyzer R. , Schiller P. W. 
Published: December 2004

AbstractWe are investigating interactions between hormones and their potential receptor molecules by means of biologically active, synthetic hormone derivatives. The substituents are so chosen that they can supply quantitative information about specific contacts or convert the hormone to an ‘affinity marker’. We describe the synthesis of Nε‐dansyllysine21‐adrenocorticotropin‐(1–24)‐tetrakosipeptide. In fat cells and in adrenal cells of the rat the dansyl substituent does not seem to impair the interaction between the peptide moiety and its biological receptors. It allows for affinity studies by fluorescence depolarisation and for measurement of intramolecular and intermolecular distances by means of energy transfer (fluorescence sensibilisation).
Über den Einfluss des Kontaktterms auf die Lantlianiden‐Verschiebung der NMR.‐Signale aromatischer stickstoffheterocyclen
Authors: Huber H. , Pascual C. 
Published: December 2004

AbstractThe inclusion of a contact term in the calculation of the paramagnetic shifts induced by Eu(tmhd3) does not Improve the predicted values.
Synthese von lipophil substituierten ACTH‐Peptiden
Authors: Brugger M. 
Published: December 2004

AbstractWith a view to rendering ACTH peptides absorbable by the oral route, a series of such peptides with increased lipophilic character was built up. This paper describes the synthesis of eleven derivatives of the ACTH peptide [D‐Ser1, Lys17,18]‐β‐corticotrophin‐(1–19)‐nonadeca‐peptide, containing lipophilic alkyl substituents of different kinds and sizes, bound to the carboxyl of terminal proline either by ester or amide linkage.The unsubstituted peptide [D‐Ser1, Lys17,18]‐β‐corticotrophin‐(1–19)‐nonadecapeptide, and its C‐terminal amide were also synthesized.
Photochemisches Verhalten von 3,4‐Diarylsydonen. Vorläufige Mitteilung
Authors: Märky M. , Hansen H.‐J. , Schmid H. 
Published: December 2004

Abstract3, 4‐Diphenyl‐sydnone (1a) and 3‐p‐tolyl‐4‐phenyl‐sydnone (1b) on irradiation with a mercury high‐pressure lamp in pyrex vessels yield 2,4,5‐triphenyl‐ (3a) and 2‐p‐tolyl‐4,5‐diphenyl‐1,2,3‐triazole (3b), respectively. Irradiation of 1a and 1b in the presence of dimethyl acetylene‐dicarboxylate or indene leads to the formation of the pyrazoles 4a and 4b and the Δ2‐pyrazolines 5a and 5b, respectively. Reactive intermediates of the photoreaction of 1a and 1b seem to be the diazirines 2a and 2b, which open to give the 1,3‐dipolar structures 8a and 8b.
Computer‐Drawn Molecular Orbitals: An aid for the users of MO‐programs
Authors: Haselbach E. , Schmelzer A. 
Published: December 2004

AbstractA computer program is described, which generates a simplified pictorial representation of computed molecular orbitals. As examples, the highest occupied MO's of the two C8‐rotamers of the cyclopropylcarbinylcation (C4H7+), of pyridine and of barrelene (bicyclo[2.2.2]octatriene) are given.
Die Kristallstruktur des (−)‐O‐Methyllaurepukins (1, 2‐Methylendioxy‐11‐methoxy‐6a, β‐aporphin‐6β‐oxid)
Authors: Oberhänsli W. E. 
Published: December 2004

AbstractThe crystal and molecular structure of the O‐methyl derivative of the aporphine alkaloid laurepukin has been determined by direct methods, which are described. A short discussion of the structure is given.
The Synthesis and Borohydride Reduction of some Alloxazine Derivatives
Authors: Müller Franz , Dudley Kenneth H. 
Published: December 2004

AbstractUnequivocal syntheses of N(1 or 3)‐mono‐substituted 7, 8‐dimethylalloxazines are described. The borohydride reduction of various alloxazines has been studied under aerobic and anaerobic conditions, in the absence of light. These reactions are discussed in relation to other work on 7, 8‐dimethylisoalloxazines (flavins) and on certain flavoproteins.
Etudes sur les composés organométalliques, XIII [1] Action d'organomagnésiens sur la benzalacétone
Authors: Dubsky George Jon , Jacot‐Guillarmod André 
Published: December 2004

AbstractThe reactions of benzalacetone with n‐BuMgBr and PhMgBr have been compared with the corresponding reactions with the diorganomagnesium complexes of ether and pyridine. The results obtained by using different mole ratios of reactants and orders of addition show that the conjugated addition reaction is enhanced if a monomeric diorganomagnesium reagent is available; this condition can be realized either by adding a diorganomagnesium complex to the ketone or by complexing the diorganomagnesium with pyridine. Probable reaction mechanisms for normal and conjugated addition reactions are suggested.
Organic phosphorus compounds 53 preparation and properties of bis‐(chloromethyl)‐phosphinic and ‐thiophosphinic acid derivatives as well as tertiary phosphine oxides and sulfides containing two ClCH2 groups [1]
Authors: Maier Ludwig 
Published: December 2004

AbstractBis‐chloromethyl‐phosphinates, ‐thiophophinates, and ‐phosphinic amides are formed in fair yield by treating either bis‐chloromethyl‐phosphinic or‐thiophosphinic chloride with alcohols, thiols, or amines in the presence of equivalent amounts of acid binding agents. Unexpectedly, the thiophosphinates show no insecticidal activity and only the β‐cumaryl derivative exhibits a low herbicidal activity.Reduction of bis‐chloromethyl‐thiophosphinic chloride to bis‐chloromethyl‐phosphinous chloride is effected with (PhO)3P at 170°. Interaction of this chloride, (ClCH2)2PCl, with Grignard reagents yields tertiary phosphines, which at slightly above room temperature are unstable, but which may be characterized as oxides or sulfides.
Equilibres conformationnels de glucides au niveau de liaisons s̀ sp2‐sp3 CC. II Dérivés d'hydrozones d'aldéhydo‐sucres
Authors: Tronchet J. M. J. , Baechler Br. , Jotterand A. , Perret Mlle F. 
Published: December 2004

AbstractA series of alkyl‐and aryl‐hydrazones of different types of aldehydo‐sugars with blocked hydroxy groups have been studied, mainly by PMR. spectroscopy. No traces of the azoalkane or ene‐hydrazine forms were detected; the hydrazones were found to exist only in the syn form, except for the cases where an intramolecular hydrogen bond between the ‘amino’ hydrogen of the hydazono group and an oxygen o the glycosyl group provides an extra‐stabilization to the anti isomer. Most of these syn hydrazones seem to exist as an equilibrium of the ‘classical’ eclipsed rotamers. The influence of solvent polarity both on configurational and conformational equilibria has been examined.The factors which determine the relative stability of the conformers about a sp2‐sp3 s̀ bond, particularly some kind of non‐bonded attraction, are discussed.
Thermische Umlagerungen von (+)‐Isopinocampheol und (−)‐Isopinocamphon
Authors: Schulte‐Elte K. H. , Gadola M. , Ohloff G. 
Published: December 2004

AbstractShort‐path thermolysis of (+)‐isopinocampheol (1) at about 330° in the gas phase yields mainly (—)‐(3 S, 4 S)‐3, 7‐dimethyl‐octa‐1,6‐dien‐4‐ol (2). Longer heating of 2 at about 290–330° yields as main products the diastereoisomeric hydroxy‐Δ8‐iridenes 3, 4 and 5 in ratios dependent on temperature. Above 400°, formation of 4‐methylpent‐3‐en‐1‐al (7) and 2‐butene (8) predominates. Compounds 7 and 8 also appear as the stable final thermolysis products of 3, 4 and 5 above 500°. Small quantities of (+)‐iso‐dihydrocarveol (6) always occur as by‐product in the thermolysis of 1.Short‐path thermolysis of (—)‐isopinocamphone (13) at about 430° leads, with slight epimerisation, to the three diastereoisomeric oxo‐Δ8‐iridenes 15, 18 and 17 via (+)‐(3 S)‐3, 7‐dimethylocta‐1, 6‐dien‐4‐one (14). Structure and stereochemistry of all reaction products are established spectroscopically and chemically.
Photochemische Reaktionen. 65.(vorläufige) Mitteilung. Spezifisch π → π*‐induzierte Photoisomerisierungen von 10‐Dimethoxymethyl‐Δ1,9‐octal‐2‐on. Ein photochemischer Zugang zu [4.4.3]‐12‐Oxapropellan‐Derivaten
Authors: Gloor J. , Schaffner K. , Jeger O. 
Published: December 2004

AbstractSelective n → π* excitation of the α,β‐unsaturated enone 1 in hydrocarbon solvents resulted in a deconjugation reaction to 3, reminiscent of results previously reported for similar systems [2], whereas the photoreactivity of 1 in alcohol solvents at wavelengths >3400 Å was so small that only product 4 has been identified as yet.Excitation of the π → π* transition of compound 1 at 2537 Å initiated additional phototransformations which could not be effected by irradiation in the first absorption band. The [4.4.3]‐12‐oxapropellane derivative 2 was identified as one of the two new major photo‐isomers. A 6:8 mixture of products 2 and 3, plus about 1 part of an isomer of still unknown structure (see however, the Addendum), were readily formed in hydrocarbon solvents, and a 1:10 ratio of 2 and the unknown product was obtained in methanol. Abstraction of a methoxyl hydrogen by the ketone oxygen is proposed to account for the primary photochemical step in the cyclization to 2. A hydrogen‐deuterium isotope effect of 2.7 was observed in a competitive experiment using 1 and 1‐d6. 34% of one deuterium atom were exchanged for hydrogen when 1‐d6 was photolyzed to 2‐d6 in t‐butyl alcohol, which suggests an intermediate of type a in the pathway 1 → 2 possessing a readily exchangeable proton.Steric considerations would require a strongly distorted, non‐planar excited‐state geometry of the enone group of 1 for the oxygen to approach a methoxyl hydrogen. The transformation 1 → 2 represents a novel reaction type in photochemical processes of conjugated enones which are specifically induced by π → π* excitation only.
Über die flüchtigen Anteile der Ananas
Authors: Näf‐Müller Regula , Willhalm B. 
Published: December 2004

AbstractA gas chromatographic investigation of the volatile part of a pineapple concentrate led to the identification of 59 substances, 35 of which were not previously found in pineapple. The identifications and syntheses of some esters (Δ3‐ and Δ4‐unsaturated, β‐hydroxy, β‐acetoxy, and δ‐acetoxy) and of a new sulfur compound are given.
The Isolation, Structure, and Synthesis of Davana Ether, an Odoriferous Compound of the Oil of Artemisia pallens Wall.
Authors: Thomas Alan F. , Pitton Gertrud 
Published: December 2004

AbstractSeveral stereoisomers of 2,6,10‐trimethyl‐2:5, 7:10‐diepoxy‐dodeca‐3,5,11‐triene (3) have been isolated from the oil of Artemisia pallens. The synthesis of the isomeric mixture is described.
Die farbstoffsensibilisierte Photo‐Oxygenierung von β‐Damascol. Ein einfaches Verfahren zur Darstellung von β‐Damascenon
Authors: Schulte‐Elte K. H. , Müller B. L. , Ohloff G. 
Published: December 2004

AbstractThe oxirane derivative 2a of β‐damascone which appears as the main product in the photo‐oxygenation of β‐damascol (1a), besides the α‐hydroxy‐hydroperoxides B and C, can easily be transformed into β‐damascenone (8) [1] by a sequence of acid catalyzed reactions.The structure and stereochemistry of the photo‐oxygenation products of 1 a and its derivatives 1 b and 1 c are determined. The epoxyketone 2 is a secondary product of the unstable allylhydroperoxide A, while ketones 12 and 13 result from an α‐hydroxy‐hydroperoxide fragmentation of B and C, respectively.
Farbstoffsensibilisierte Photo‐Oxygenierung von 6,6‐Dimethylfulven. Eine neue 1,2‐Dioxolan‐Umlagerung
Authors: Skorianetz W. , SchulteW‐Elte K. H. , Ohloff G. 
Published: December 2004

AbstractThe dye sensitized photo‐oxygenation of 6,6‐dimethylfulvene (1) in solution at 15° gives enol lactone 2, along with ketoles 3 and 4. The following mechanism is proposed: initially formed endoperoxide 11 undergoes a 1,2‐dioxolan rearrangement to give allen epoxide 12, which then isomerizes to cyclopropanone 13. 13 can then cyclise to give 2 and 3.
Theoretical Study of the Structure and the Physico Chemical Properties of 1,2‐Benzyne
Authors: Haselbach E. 
Published: December 2004

AbstractThe structure of 1,2‐benzyne (I) has been optimized with respect to its total molecular energy using the MINDO/2 SCF‐procedure. The results indicate a bond length of ∼1.26 Å for the strained triple bond. The overall geometry suggests that I possesses considerable resonance energy. The calculated heat of formation (ΔHf(I) = 107 kcal/mole) is in good agreement with an estimate from mass spectrometric studies (ΔHfexp(I) = 118 ± 5 kcal/mole). From model calculations for bent acetylene the strain energy of I is estimated to be about 60 kcl/mole. Some chemical reactions of I are discussed in the light of the results.
Kernquadrupolresonanz von 35Cl in Chloracetylenen
Authors: Gerber P. , Labhart H. , Kloster‐Jensen Else 
Published: December 2004

AbstractNuclear quadrupole coupling constants of 35Cl observed in a series of chloroacetylenes are compared with results from quantum‐chemical estimates of different degree of refinement. The correlation with values calculated by an iterative Extended Hückel procedure in the Townes‐Dailey approximation is bad. It can be strikingly improved by introducing a correction proportional to the net charge on the carbon atom adjacent to the Cl‐atom. The correlation is then of the same quality as with ab initio calculations by Straub & McLean.
Solvolysis of α‐Bromo‐p‐aminostyrene. Mesomeric vinyl cations, Part IV
Authors: Grob C. A. , Pfaendler H. R. 
Published: December 2004

AbstractThe preparation of α‐bromo‐p‐aminostyrene (1b) and its solvolysis rates and products have been reexamined in detail. In buffered 50 vol % aqueous dioxane between pH* 13 and 3 the reaction rate is independent of hydrogen ion concentration. The ratio of the solvolysis products, viz. p‐aminoacetophenone (3b) and p‐aminophenylacetylene (5a), however, varies with the pH* and with the buffer concentration.These findings confirm the unimolecular (SN1‐E1) mechanism involving an intermediate vinyl cation. The acid‐catalysed hydration mechanism proposed by Schubert & Barfknecht is thereby excluded.
On the Mechanism of the Thermal and Photolytic Cyclization of Diphenylamines to Carbazoles
Authors: Wentrup C. , Gaugaz M. 
Published: December 2004

AbstractThe product of photolysis of di‐p‐tolyamine in petroleum ether is 3,6‐dimethylcarbazole. The primary product of gas‐phase thermolysis of di‐p‐tolylamine at 850–1000°/0.01–0.05 Torr is also 3,6‐dimethylcarbazole. In the higher temperature range monomethylcarbazole and carbazole are also formed. Thermolysis of tetra‐p‐tolylhydrazine at 800–1000° gives only di‐p‐tolylamine, the latter decomposing further in the higher temperature range. It is concluded that carbazole formation involves in both cases an electrocyclization of the ortho‐positions, and not a rearrangement, and that diphenylaminyl is not an intermediate.
Photoinduzierte nucleophile Substitution von 3‐substituierten 2,1‐Benzisoxazolen (unter Ringöffnung)
Authors: Giovannini E. , Rosales J. , De Souza B. 
Published: December 2004

AbstractOn UV.‐irradiation in strongly acidic solution 3‐alkyl‐ and 3‐aryl‐2,1 benzisoxazoles, respectively, yield 5‐substituted 2‐aminophenylketons.
Alkaloide aus Evonymus europaea L.
Authors: Klásek A. , Šantavý F. , Duffield M. A. , Reichstein T. 
Published: December 2004

AbstractFrom the seeds of Evonymus europaea L. (Celastraceae) the three previously described alkaloids A, B and C were isolated and their empirical formulae determined by mass spectrometry. Alkaloid B, now named evozine, C32H39NO15 (14), alkaloid A, now named evorine, C34H41NO16 (15), and alkaloid C, shown to be identical with Parter's & Libiseller's evonine, C36H43NO17 (17), are respectively tri‐, tetra‐, and penta‐O‐acetyl derivatives of deacetylevonine (13), C26H33NO12. Vigorous alkaline hydrolysis of the latter yields the previously known evonic acid (3).Deacetylevonine (13) is an ester of evonic acid (3) and a hypothetical polyhydroxy compound C15H24O10 (2), which is unstable on alkaline hydrolysis.By partial saponification and partial acetylation, these three alkaloids can be converted into each other, at the same time giving rise to a fourth alkaloid D (16), C34H41NO16, which we name iso‐evorine. This had been obtained already by M. Osowiecki (unpublished).
Base‐Catalyzed Hydrogen‐Deuterium Exchange in Sulfonium Cations
Authors: Barbarella G. , Garbesi A. , Fava A. 
Published: December 2004

AbstractThe effects of various structural changes on the kinetic acidity of protons alpha to a sulfonium function are reported. These effects are consistent with a transition state closely resembling a carbanion. Strong rate enhancements are observed for the 4‐membered cyclic sulfonium cation but not for the other ring systems.In 5‐membered cyclic sulfonium cations the diastereotopic ring protons show high stereoselectivity towards abstraction by a base. Such stereoselectivity is diminished in going from D2O to dimethyl sulfoxide‐d6‐D2O mixtures. By contrast no stereoselectivity is exhibited by the ring protons of the 6‐ and 7‐membered cyclic sulfonium cations.Although the rates for acyclic and cyclic sulfonium cations are closely similar, the activation parameters are characteristically different. It is suggested that solvation phenomena may be responsible for this behaviour.
Hydrolyse acide du p‐nitrophényl‐diazométhane dans les mélanges H2OD2O: analyse des effets isotopiques
Authors: Diderich G. , Dahn H. 
Published: December 2004

AbstractThe velocity of the hydrogen ion catalysed hydrolysis of p‐nitrophenyl‐diazo‐methane (I) has been measured in H2OD2O mixtures, giving an isotopic αi = 0.49. The product isotope effect r = 5.1, determined from product analyses, combined with the (overall) solvent isotope effect kH/kD = 2.81, yields the primary kinetic isotope effect (kH/kD)I = 3.8, and the secondary kinetic isotope effect (kH/kD)II = 0.75. The CICH2COOH‐catalysed hydrolysis of I in H2OD2O mixtures gave a straight‐line plot of kn/kH versus the atomic fraction n of deuterium. With four carboxylic acids, as catalysts, values of about 4.3 for the kinetic (overall) isotope effects were observed.
‘Alkaloids’ in Mammalian Tissues. I. Condensation of L‐Dopa and its two mono‐O‐methyl ethers with formaldehyde and acetaldehyde
Authors: Brossi A. , Focella A. , Teitel S. 
Published: December 2004

AbstractIn der Annahme, dass gewisse Aminosäuren im Gewebe von Säugetieren Vorläufer für «alkaloidische» Tetrahydro‐isochinoline sein könnten, wurden L‐Dopa und dessen zwei Monomethyläther mit Formaldehyd und Acetaldehyd kondensiert. Die absolute Stereochemie der erhaltenen 1‐Methyl‐substituierten Tetrahydro‐isochinoline wurde durch Röntgen‐Analyse einer Schlüsselverbindung sichergestellt.
A Novel Synthesis of 2,6‐Diolefinic Esters: Ethyl and methyl trans‐2,cis‐6‐dodecadienoate, two Bartlett pear constituents
Authors: Näf F. , Degen P. , Ohloff G. 
Published: December 2004

AbstractEthyl and methyl trans‐2, cis‐6‐dodecadienoate, two Bartlett pear constituents, have been prepared by a novel two‐step synthesis: 1,6‐addition of lithium di‐cis‐1‐heptenylcuprate to ethyl or methyl trans‐2,4‐pentadienoate gave exclusively the 3,6‐diolefinic esters, which were isomerized to the desired 2,6‐diolefinic esters. The double‐bond geometry of the vinyl unit is retained during the addition step.
Quinacridones: Structure and Mechanism of Formation
Authors: Altiparmakian R. H. , Bohler H. , Kaul B. L. , Kehrer F. 
Published: December 2004

AbstractThe NMR. spectra of two acridones and twenty‐two quinacridones in (CD3)2SONaOD are reported. A NMR. technique is described for determining the composition of mixtures of various substituted quinacridones. A general mechanism is proposed for quinacridone formation via cyclodehydration of 2,5‐diarylamino‐terephthalic and 2,5‐diarylamino‐1,4‐benzoquinone‐3,6‐dicarboxylic acids/esters.