bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alkylation des β‐énaminoesters cycliques: Relation entre la taille et la réactivité
Authors: Célérier Jean‐Pierre , Deloisy‐Marchalant Elisabeth , Lhommet Gérard 
Published: April 2009

AbstractLes β‐enaminoesters cycliques sont C‐alkylés régiospécifiquement et seul l'isomère Z est obtenu. Les conditions opératoires différent selon la taille du cycle, plus douces avec les cycles de grande taille et plus drasti‐ques avec les petits cycles où la conjugaison est plus importante. Différentes données physicochimiques permettent d'avencer une explication reliant la différence de réactivité avec la taille du cycle des β‐énaminoesters.
Synthèse de derivès du nitro‐5 imidazole potentiellement actifs en chimiothèrapie
Authors: Alcalde Ermitas , Mañás Laura , Valls Natividad , Elguero José 
Published: April 2009

AbstractSix derivés du méthyl‐2 nitro‐5 imidazole portant en position 1 une chaîne CH2CH2Het, Het étant un sel de pyridinium ou d'imidazolium 1‐substitué ont été synthétises. Ils ont fait l'objet d'une étude rmn, proton et carbone‐13, comparativement á d'autres nitroimidazoles. Ces composés ne présentent pas d'activité cytostatique.
The thermal isomerization of 1‐(α‐aroyloxybenzylideneamino)‐4,5‐di‐methyl‐1,2,3‐triazoles (isoimides) to the corresponding imides
Authors: Maroulis A. J. , Hadjiantoniou‐Maroulis C. P. 
Published: April 2009

AbstractThe title isoimides rearrange upon heating to the corresponding imides through a [1,3] O⇀N aroyl transfer. The reaction is slightly accelarated by electron withdrawing substituents in the migrating moiety and retarded by electron donating as it is suggested by the positive (+0.5) Hammett ϱ value. The mechanism operating is either a rate determining nucleophilic attack by the nitrogen lone pair on the carbonyl carbon or a sigmatropic [π2s + σ2a] process which does not involve the lone pair of electrons on nitrogen and π or‐bitals of the carbonyl group.
Synthesis and CMR analysis of phenoxazinone derivatives related to the actinomycin D chromophore
Authors: Sehgal Raj K. , Sengupta Sisir K. , Dieter R. Karl 
Published: April 2009

AbstractSynthesis of 2‐deamino‐ and 2‐deamino‐2‐nitro‐chromophores of actinomycin was accomplished by reaction of nitrous acid in fluoroboric acidviadiazotization of the 2‐amino group in the chromophore. Structural assignments were made by cmr and pmr.
Préparation d'aryloxyméthyl‐1 triazoles‐1,2,3
Authors: Loubinoux Bernard , Colin Jean‐Luc , Tabbache Samir 
Published: April 2009

AbstractLa synthèse d'aryloxyméthyl‐1 triazoles‐1,2,3, régulateurs de croissance potentiels des végétaux, est réalisee par cycloaddition de composés acétyléniques sur les azides correspondants; ces derniers sont eux‐mêmes préparés par réaction entre l'azidure de sodium et les chlorures d'aryloxyméthyles.
Dérivés de la dihydro‐2,4 triazole‐1,2,4 thione‐3 et de l'amino‐2 thiadiazole‐1,3,4 à partir de nouvelles thiosemicarbazones d'esters
Authors: Malbec Frédérique , Milcent René , Barbier Géo 
Published: April 2009

AbstractUne nouvelle synthèse générale des dihydro‐2,4 triazole‐1,2,4 thiones‐3 disubstituées en position 4 et 5 est proposée. Ces hétérocycles sont obtenus par action d'amines primaires, d'arylhydrazines ou d'aroylhydrazines sur les thiosemicarbazones d'esters. Celles‐ci sont préparées par action de chlorhydrates d'iminoéthers sur la thiosemicarbazide dans le diméthylformamide. Les thiosemicarbazones se prêtent à d'autres réactions avec les acides forts, les anhydrides et chlorures d'acides; par thermolyse, ils donnent des dérivés de l'amino‐2 thiadiazole‐1,3,4. Enfin, deux dérivés du [1,2,4triazolo][3,4‐b]thiadiazole‐1,3,4 ont été préparés.
The reaction of chlorosulfonyl isocyanate with epoxides. A novel conversion of epoxides to cyclic carbonates
Authors: Murthy K. S. Keshava , Dhar D. N. 
Published: April 2009

AbstractThe facile reaction of chlorosulfonyl isocyanate (CSI) with epoxides is described. The initially formed 2‐chlorosulfonylimino‐1,3‐dioxolane 2a‐e and N‐chlorosulfonyl‐1,3‐oxazolidin‐2‐one 3a‐e derivatives undergo smooth hydrolysis to yield the corresponding 1,3‐dioxolan‐2‐one 4a‐e and 1,3‐oxazolidin‐2‐one 5a‐e derivatives respectively. This reaction sequence provides a convenient one‐pot method for the conversion of epoxides to cyclic carbonates. Substrates such as 1g‐i are exceptions to this otherwise general reaction pathway.
Pyridazines. XXIII. A novel pyridazine into pyrazole ring transformation
Authors: Heinisch Gottfried , Waglechner Richard 
Published: April 2009

AbstractTreatment of phenyl(4‐pyridazinyl)methanols 1a and 1b with p‐toluenesulfonic acid at elevated temperatures causes transformation into the C‐4 substituted pyrazole derivatives 8a and 8b. Limitations of this novel rearrangement reaction as well as mechanistic considerations are discussed. Furthermore, the preparation of hitherto unknown 4‐pyridazinylmethanols 1b, 3, and 7 is described.
Reaction of methyl tetronate with some amines. Synthesis of substituted 4‐aminobut‐2‐enolides
Authors: Shandala Mowafak Y. , Ayoub Mikdad T. , Mohammad Moyayed J. 
Published: April 2009

AbstractA series of substituted 4‐aminobut‐2‐enolide derivatives have been synthesized by reaction of a variety of substituted amines with methyl tetronate. The 1H and 13C nmr spectral analysis of all compounds synthesized are given.
Reaction of ethyl γ‐bromo‐β‐methoxycrotonate with carbonyl compounds. Synthesis of 4‐methoxy‐6‐substituted‐5,6‐dihydro‐2H‐pyran‐2‐ones and 3‐substituted 3‐pyrazolin‐5‐ones
Authors: Shandala Mowafak Y. , Ayoub Mikdad T. , Mohammad Mouayed J. 
Published: April 2009

AbstractEthyl β‐methoxycrotonate I reacts with substituted carbonyl compounds II in benzene to give 4‐methoxy‐6‐substituted‐5,6‐dihydro‐2H‐pyran‐2‐ones III. The reaction of IIIa and j with hydrazine hydrate in ethanol leads to 3‐[(1′‐thienyl‐1‐hydroxy)methyl]‐5‐hydroxy‐1H‐pyrazole (IVa) and 3‐[1′‐styryl‐1′‐hydroxy)methyl]‐5‐hydroxy‐1H‐pyrazole (IVj) in good yields. The structure of the products were assigned and confirmed on the basis of their elemental analysis and the electronic absorption, infrared and nmr spectra.
Synthèse de dérivés imidazopyridiniques et pyridinotriaziniques
Authors: Mayrargue Joëlle , Labidalle Serge , Randriatsoa Jean , Moskowitz Henri , Miocque Marcel 
Published: April 2009

AbstractLes propargyl‐1 pyridiniums substitues en 2 par un reste hydroxylamine ou hydrazine se cyclisent par chauffage en imidazopyridiniums. Les analogues substitués par la méthylhydrazine ou la N,N‐diméthylhydrazine sont, dans les mèmes conditions, cyclisés avec formation de pyridino‐as‐triaziniums. Cette différence de réactivaté est discutée.
Synthesis of new derivatives of 4‐amino‐2,4‐dihydro‐1,2,4‐triazol‐3‐one as potential antibacterial agents
Authors: Malbec Frédérique , Milcent René , Vicart Patrick , Bure Anne Marie 
Published: April 2009

AbstractThirty new 2‐substituted‐4‐amino‐5‐alkyl or aryl‐2,4‐dihydro‐1,2,4‐triazol‐3‐ones and ten 2‐substituted‐5‐alkyl or aryl‐4‐(5‐nitro‐2‐furfurylidene)amino‐2,4‐dihydro‐1,2,4‐triazol‐3‐ones were synthesized and characterised by their sharp melting points, elemental analysis, ir and 1H nmr spectra. These new derivatives of 5‐nitro‐2‐furaldehyde were screened for their antibacterial activities. Most of the compounds showed good activity against one test organism, Staphylococcus aureus. For a few compounds, C.M.I. ranged from 4 to 8 μg/ml (higher results than nitrofurantoin).
The synthesis of polycyclic thiophenes derived from phenanthrene intermediates
Authors: Baldwin Larry J. , Tedjamulia Marvin L. , Stuart John G. , Castle Raymond N. , Lee Milton L. 
Published: April 2009

AbstractThe synthesis of benzo[b]triphenyleno[2,1‐d]thiophene (9), benzo[b]triphenyleno[1,2‐d]thiophene (13), 5‐methylbenz[7,8]anthra[2,1‐b]thiophene (17), l‐methylchryseno[3,4‐b]thiophene (18), triphenyleno[1,2‐c]dibenzothiophene (22), triphenyleno[2,1‐a]dibenzothiophene (26), triphenyleno[1,2‐a]dibenzothiophene (29), and triphenyleno[2,1‐b]dibenzothiophene (30) is described.
MNDO studies on five‐membered 1,3‐heterocyclic systems. Part I. The acidity of the azolium cations
Authors: Geijo Fernando , López‐Calahorra Francisco , Olivella Santiago 
Published: April 2009

AbstractThe technique of energy partitioning in the MNDO SCF‐MO method has been used to understand the main electronic factors which determine the acidity order of the azolium cations. It is found that the greater acidity of thiazolium cation relative to the imidazolium one can be ascribed to a substantial stabilization of the one‐center energy term associated to the sulphur atom in the conjugate base, suggesting a higher effective electronegativity of this atom.
Studies on the synthesis of heterocyclic compounds. XV. Preparation of a new series of macrocycles with the diglycolyl moiety
Authors: Podda Gianni , Anchisi Carlo , Corda Luciana , Fadda Anna Maria , Maccioni Antonio 
Published: April 2009

AbstractA new series of macrocycles containing the diglycolyl moiety have been prepared. The compounds prepared were: 7,9,18,20‐tetrahydrodibenzo[b,k][1,4,7,10,13,16]hexaoxacyclooctadecin‐6,10,17,21‐tetraone (1), 1,4,7,10,13,16‐hexaoxacyclooctadecane‐2,6,11,15‐tetraone (2), 8,7,17,18‐tetramethyl‐1,4,7,10,13,16‐hexaoxa‐cyclooctadecane‐2,6,11,15‐tetraone (3) and 2,5,8,15,18,21 ‐hexaoxatricyclo[20,4,0,09.14]hexacosan‐3,7,16,20‐tetraone (4). The compound 4 has been isolated in the four diastereoisomers: trans‐syn‐trans 4a, trans‐anti‐trans 4b, cis‐syn‐cis 4c and cis‐anti‐cis 4d.
Factors which influence the formation of oxadiazoles from anthranilhydrazides and other benzoylhydrazines
Authors: Peet Norton P. , Sunder Shyam 
Published: April 2009

AbstractThe cyclization of o‐aminobenzoylhydrazine (1a) and its 5‐methyl derivative 1b with four equivalents and with one equivalent of triethyl orthoacetate (TEOA) was studied. 3‐Amino‐2‐methyl‐4(3H)‐quinazolinone (2a), 3,4‐dihydro‐2‐methyl‐5H‐1,3,4‐benzotriazepin‐5‐one (3a) and an imino ether derivative of 2a, N‐[2‐methyl‐4‐oxo‐3(4H)quinazolinyl]ethanimidic acid ethyl ester (4a) were obtained from the reaction of 1a with four equivalents of TEOA. These results were compared with those of Merour [1] who isolated 2a and 3a using the same conditions. When 1a was treated with one equivalent of TEOA, 2a, 3a, and a new product, 2‐(5‐methyl‐1,3,4‐oxadiazol‐2‐yl)benzenamine (5a) were produced, and 4a was not. Similar results were obtained with the reactions of 1b with TEOA. Authentic samples of oxadiazoles 5a and b were prepared by alternate routes. Novel acid‐catalyzed rearrangements of benzotriazepinones 3a and b, to mixtures of aminoquinazolinones 2a and b and oxadiazoles 5a and b, respectively, were found. The different relative amounts of aminoquinazolinones 2 and oxadiazoles 5 which were produced from these rearrangements allowed us to choose between two potential mechanisms for these interesting rearrangements. Treatment of 5‐nitrobenzoylhydrazine (37) with four equivalents of TEOA gave three products which were characterized, but did not lead to benzotriazepinone formation.
1,3,4‐Benzotriazepinones. Formation and rearrangement
Authors: Scheiner Peter , Frank Leroy , Giusti Irene , Arwin Sara , Pearson Shirley A. , Excellent Frendy , Harper Althea P. 
Published: April 2009

AbstractAnthranilic hydrazide reacts with orthoesters to produce mixtures of 3 products: 3,4‐dihyro‐5H‐1,3,4‐benzotriazepin‐5‐ones (1), 3‐amino‐3,4‐dihydro‐4‐quinazolinones (2) and 2‐(2‐aminophenyl)‐1,3,4‐oxadiazoles (4). The origin of these materials has been investigated. Product distributions depend on the nature of substituents, solvent and time. In ethanol benzotriazepinones are kinetically favored, but formed reversibly they subsequently rearrange to 2 and 4. Aminoquinazolinone formation is suppressed in aprotic solvents at moderate temperatures. Earlier failures to obtain 1 are due to its tendency to isomerize. Acid, base and thermal rearrangements have been observed. Mechanisms are proposed for the formation of 1, 2 and 4, and for the rearrangements of the benzotriazepinones. Pyrazolo‐ and imidazotriazepinones have been prepared from the corresponding o‐aminoazole hydrazides.
1‐Ethyl‐1,4‐dihydro‐4‐oxo‐7‐(pyridinyl)‐3‐quinolinecarboxylic acids. II. Synthesis
Authors: Carabateas Philip M. , Brundage R. Pauline , Gelotte Karl O. , Gruett Monte D. , Lorenz Roman R. , Opalka Chester J. , Singh Baldev , Thielking William H. , Williams Gordon L. , Lesher George Y. 
Published: April 2009

AbstractThe preparation of a variety of 1‐ethyl‐1,4‐dihydro‐4‐oxo‐7‐pyridinyl‐3‐quinolinecarboxylic acids with a range of substituents on the pyridine ring is described. Starting with the appropriately substituted aniline and using the first two steps of the Gould‐Jacobs quinoline synthesis the 7‐pyridinyl‐3‐quinolinecarboxylates can be obtained. Ethylation at the 1‐position and hydrolysis of the ester group gives the desired acid products. These compounds have significant antibacterial activity: 1‐ethyl‐1,4‐dihydro‐4‐oxo‐7‐(4‐pyridinyl)‐3‐quinolinecarboxylic acid is now in clinical study and 7‐(2,6‐dimethyl‐4‐pyridinyl)‐1‐ethyl‐1,4‐dihydro‐4‐oxo‐3‐quinolinecarboxylic acid is under advanced evaluation.
The synthesis of 4‐methyl‐2‐pyrrolidones and 3‐methyl‐1‐pyrrolidines and their mass spectral study
Authors: Lin Tay‐Yean , Kingsbury Charles A. , Cromwell Norman H. 
Published: April 2009

AbstractA number of 1‐alkyl‐4‐methyl‐2‐pyrrolidones have been prepared from methyl 4‐alkylamino‐3‐methyl butenoates. The corresponding 1‐alkyl‐3‐methyl‐pyrrolidines are obtainable by the reduction of the pyrrolidones with lithium aluminum hydride. The mass spectra of pyrrolidones and pyrrolidines have been studied. Three different mechanisms which lead to the base peak have been proposed.
Total assignment of the 13C‐NMR spectra of 5H‐indolo[1,7‐ab][1]benzazepine and 6,7‐dihydro‐5H‐indolo[1,7‐ab][1]benzazepine using two‐dimensional proton‐carbon chemical shift correlation experiments
Authors: Hallberg Anders , Martin Arnold R. , Martin Gary E. , Grönberg Gunnar 
Published: April 2009

Abstract13C‐nmr chemical shift assignments for 5H‐Indolo[1,7‐ab][1]benzazepine and 6,7‐Dihydro‐5H‐indolo‐[1,7‐ab][1]benzazepine, made on the basis of two‐dimensional 1H‐13C chemical shift correlation experiments are reported.
1‐Iminoalkylimidazoles via cuprous imidazolide
Authors: Castro C. E. , Wade R. S. , Fukuto J. 
Published: April 2009

Abstract1‐Iminoalkylimidazoles are obtained from the novel reaction of cuprous imidazolide with alkyl halides and nitriles. The condensation produces a new class of imidazole derivatives and the ease of the reactions suggests a reasonable scope. The compound N‐(1‐N‐t‐butylimino)ethylimidazole exhibits nematicidal activity against larvae of Meloidogyne javanica at 1 ppm.
Effect of late 1970's climate shift on tropospheric biennial oscillation—role of local Indian Ocean processes on Asian summer monsoon
Authors: Pillai Prasanth A , Mohankumar K 
Published: April 2009

AbstractThe tropical climate has undergone noticeable changes on interdecadal time scales. The climate shift that occurred in the late 1970s attained enormous attention owing to its global‐scale variations in ocean temperature, heat content and El Nino Southern Oscillation (ENSO) properties. Earlier studies presented the effect of this shift on ENSO and the Asian summer monsoon–ENSO relationship. The present study is an attempt to investigate the effect of late 1970's climate shift on tropospheric biennial oscillation (TBO), which is an important tropical phenomenon that includes both air–sea processes in the tropical Indian and Pacific Ocean regions. TBO is the tendency for the Asian–Australian monsoon system to alternate between relatively strong and weak years. The study comprises a detailed analysis of the TBO cycle in the time periods before (1951–1975) and after (1978–2002) the climate shift in 1976 with the help of National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) data sets of 200‐hPa velocity potential; the Indian Ocean sea surface temperature (SST) and circulation are more obvious after the shift, although they were significant in the Pacific Ocean before 1976. The effect of ENSO in the biennial cycle is reduced with climate shift. The persistence of Asian‐to‐Australian summer monsoon has weakened in recent decades, as it is controlled by ENSO. Local oceanic processes in the Indian Ocean and local monsoon Hadley circulation have an increased role in the biennial oscillation of the Asian summer monsoon after 1976. Copyright © 2009 Royal Meteorological Society
Antioxidant activity determines on‐tree maturation in ‘Golden Smoothee’ apples
Authors: Molina‐Delgado Diana , Larrigaudière Christian , Recasens Inmaculada 
Published: April 2009

AbstractBACKGROUND: Harvest date clearly determines the postharvest storage behaviour and sensitivity of fruit to physiological disorders. Generally fruit are picked following their maturity indexes but often these indexes poorly represent the physiological state of the fruit. With this in mind, this work aimed to determine a biochemical marker capable of predicting on‐tree maturation in ‘Golden Smoothee’ apples. Changes in the non‐enzymatic and in enzymatic antioxidant potential of fruit were assessed for different harvest dates.RESULTS: Significant differences in antioxidant levels, especially ascorbate and catalase, were found. These changes were related to climatic variations, especially relating to temperature, that appeared to determine the capability of the fruit to produce ethylene. Fruit exposed to higher temperature produced less ethylene and exhibited a significant delay in the induction of their climacteric. In both seasons, changes in quality parameters during on‐tree ripening were not related to the capability of the fruit to produce ethylene, but rather to endogenous levels of antioxidants, especially catalase and ascorbate, at the earliest picking date.CONCLUSION: We hypothesize that ascorbate and antioxidant activity play a role in changes in maturity patterns exhibited by apples in orchards. Both parameters appear to be interesting markers to follow these changes. Copyright © 2009 Society of Chemical Industry
Chemical affinities between the major volatile compounds present in a grape pomace distillate
Authors: Cortés Sandra , Gil M Luisa , Fernández Esperanza 
Published: April 2009

AbstractBACKGROUND: The distillation of vinification by‐products to obtain alcoholic drinks is potentially an important source of income for the producing countries and avoids the environmental problem of waste management. Traditional technologies of distillation involve an important cost in terms of time and staff. Nowadays, companies install new distillation equipment, with high capacity and equipped with rectification columns, which is an important advance. Nevertheless, few studieshave been published concerning their correct management. In this study, the major volatile compounds were determined by gas chromatography in 61 samples of grape pomace distillate, corresponding to the fractions collected during seven complete distillation cycles.RESULTS: With a high degree of significance, the concentrations of 1,1‐diethoxyethane, propanol, hexanoate and ethyl acetate present positive correlations with the ethanol. However, those of benzyl alcohol, 2‐phenylethanol, furfurol, lactate, ethyl mirystate and diethyl succinate, were negative, which indicates that both groups of compounds were vented in the fractions of major or minor alcoholic degree, respectively. In addition, knowledge of the relationships between the volatile compounds contributes to improved management of an industrial distillation unit.CONCLUSION: The correlations established between the concentrations of the different volatile compounds indicate their physico‐chemical affinities or their biochemical origin. Copyright © 2009 Society of Chemical Industry
The role of surgical intervention in the management of duodenal lymphoma
Authors: Sarkhosh Kourosh , Bathe Oliver F. , Stewart Douglas A. , Mack Lloyd A. 
Published: April 2009

AbstractBackground and ObjectivesThe role of surgical management in duodenal lymphoma is controversial due to the rarity of this tumor subtype. A retrospective review of a provincial cancer registry was performed to assess the rationale for surgical management in duodenal lymphoma.MethodsPatient demographics, presentations, pathologies, surgical interventions, treatment, and associated disease‐specific survival were assessed and descriptively presented.ResultsFrom 1985 to 2005, 23 patients (mean age 58 years [22–82]) were diagnosed. The most common histology was large B‐cell lymphoma (74%). A significant proportion presented in a complicated fashion: obstruction (30%), perforation (17%), and hemorrhage (4%). Eight patients (35%) were treated with surgery alone, eight (35%) with surgery and chemotherapy, five (22%) with chemotherapy alone, and two (9%) with supportive care. Of those treated with surgery, indications were mostly emergent conditions including obstruction (58%), perforation (33%), and hemorrhage (8%). Overall median follow‐up was 14 months (1–168 months) and overall median survival was 12 months (1–168 months). There were no significant differences in survival by histology, stage, or treatment type.ConclusionsChemotherapy continues to represent the therapeutic mainstay for GI lymphomas. However, in duodenal lymphoma, a high proportion of patients require surgery mainly because of complicated presentations. J. Surg. Oncol. 2009;99:428–432. © 2009 Wiley‐Liss, Inc.
HILIC LC‐MS for the determination of 2′‐C‐methyl‐cytidine‐triphosphate in rat liver
Authors: Pucci Vincenzo , Giuliano Claudio , Zhang Rena , Koeplinger Kenneth Alan , Leone Joseph F. , Monteagudo Edith , Bonelli Fabio 
Published: April 2009

AbstractA very accurate and selective LC‐MS/MS method was developed and validated for the quantification of 2′‐C‐modified nucleoside triphosphate in liver tissue samples. An efficient pretreatment procedure of liver tissue samples was developed, using a fully automated SPE procedure with 96‐well SPE plate (weak anion exchange sorbent, 30 mg). Nucleotide hydrophilic interaction chromatography has been performed on an aminopropyl column (100 mm×2.0 mm, 3 μm) using a gradient mixture of ACN and ACN/water (5:95 v/v) with 20 mM ammonium acetate at pH 9.45 as mobile phase at 300 μL/min flow rate. The 2′‐C‐modified nucleoside triphosphate was detected in the negative ESI mode in multiple reaction monitoring (MRM) mode. Calibration curve was linear over the 0.05–50 μM concentration range. Satisfying results, confirming the high reliability of the established LC‐MS/MS method, were obtained for intraday precision (CV = 2.5–9.1%) and accuracy (92.6–94.8%) and interday precision (CV = 9.6–11.5%) and accuracy (94.4–102.4%) as well as for recovery (82.0–112.6%) and selectivity. The method has been successfully applied for pharmacokinetic studies of 2′‐C‐methyl‐cytidine‐triphosphate in liver tissue samples.