bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies with enaminones: The reaction of enaminones with aminoheterocycles. A route to azolopyrimidines, azolopyridines and quinolines
Authors: Almazroa Sarah , Elnagdi Mohamed H. , El‐Din Abdellatif M. Salah 
Published: March 2009

AbstractThe enaminones 1b,d,f react with 4‐phenyl‐3‐methyl‐5‐pyrazoleamine 3a to yield the pyrazole derivatives 4a‐c that cyclised readily on reflux in pyridine solution in presence of hydrochloric acid to yield the pyrazolo[1,5‐a]pyrimidines 5a‐c. Similarly 3(5)‐amino‐1H‐triazole (3b) reacted with 1b,d,f to yield the triazolo[1,5‐a]pyrimidines 5d‐f. In contrast attempted condensation of the 5‐tetrazoloamine (3c) with 1a,d,e resulted in its trimerisation and only triaroylbenzene 8a,d,e was isolated. The reaction of 1a,b,d with anthranilonitrile 9a and the reaction of 1a‐c with the 2‐aminocyclohexene thiophene‐3‐nitrile 10a afforded the cis enaminones 11a‐c and 12a‐c. Similarly, reaction of 1a‐c with the methylanthranilate 9b and reaction of 1b,e with ethyl 2‐aminocyclohexene thiophene‐3‐carboxylate 10b afforded the cis enaminones 11d‐f and 12d,e respectively. Attempted cyclization of 11a‐c into quinoline failed. Successful cyclization of 11d into the quinolinone 13 could be affected, on heating for five minutes in a domestic microwave oven at full power. The reaction of 1a‐c,f with piperidine afforded the trans enaminones 14a‐d. Similarly, trans 14e was formed from the reaction of 1b with morpholine. The coupling reaction of 1b with excess of benzene diazonium chloride afforded the formazane 16. The enaminone 2 reacted with heterocyclic amines to yield the pyridones 17,18.
Study of the structure of 1‐hydroxymethylindazole and 1‐hydroxymethylbenzotriazole by X‐ray crystallography, multinuclear NMR in solution and DFT calculations
Authors: Alkorta Ibon , Elguero José , Jagerovic Nadine , Fruchier Alain , Yap Glenn P. A. 
Published: March 2009

Abstract1‐Hydroxymethylindazole and 1‐hydroxymethylbenzotriazole have been studied in solution by 1H, 13C and 15N NMR spectroscopy and the X‐ray structure of the second compound determined. DFT and GIAO calculations have been used to discuss geometries, energies (comparatively with 2‐substituted isomers) and NMR chemical shifts.
Pyrrolocarbazole analogs of aromatic skeleton of indolocarbazole natural products
Authors: Fousteris Manolis A. , Koutsourea Anna I. , Arsenou Evaggelia S. , Nikolaropoulos Sotiris S. , Stamos Ioannis K. , Leondiadis L. 
Published: March 2009

AbstractThe synthesis of seven pyrrolo[2,3‐a]carbazoles derivatives using Fischer indole cyclization conditions is described. Polyphosphoric acid trimethylsilyl ester was used as a mild catalyst for the cyclization step of intermediate arylhydrazones which were prepared from ethyl 7‐oxo‐4,5,6,7‐tetrahydroindole‐2‐carboxylate and used as such without further purification. In all cases a mixture of two products was obtained, the dihydro and the corresponding dehydrogenated one. The completion of the dehydrogenation was achieved by treatment of this resultant mixture with dichlorodicyanoquinone.
Synthesis, NMR spectra and X‐ray data of chloro and dichloro derivatives of 3‐hydroxy‐2‐phenylquinolin‐4(1H)‐ones and their cytostatic activity
Authors: Hradil Pavel , Krejčí Petr , Hlaváč Jan , Wiedermannová Iveta , Lyčka Antonín , Bertolasi Valerio 
Published: March 2009

AbstractAs known, some derivatives of quinolin‐4(1H)‐one possess interesting biological properties. The biological and cytostactic activity of 2‐substituted 3‐hydroxyquinolin‐4(1H)‐ones has not been reported yet. In this paper the synthesis of a series of chloro and dichloro 2‐phenyl‐3‐hydroxyquinolin‐4(1H)‐ones and their characterization by NMR spectra and X‐ray data is described. Their cytostatic properties have been evaluated and the results are reported.
Facile synthesis, spectral characterization and antimicrobial activity of 6‐substituted‐2,4,8,10‐tetra‐t‐butyl dibenzo[d,g][1,3,6,2]dioxathiaphosphocin 6‐oxides
Authors: Kasthuraiah M. , Kumar K. Ananda , Reddy C. Suresh 
Published: March 2009

AbstractSeveral novel 2,4,8,10‐tetra‐t‐butyl‐6‐substituted dibenzo[d,g][1,3,6,2]dioxathiaphosphocin 6‐oxides were synthesized in high yield by cyclocondensation of 2,2′‐thiobis(2,4‐di‐t‐butylphenol) with phosphorus oxychloride in the presence of triethylamine and a catalytic amount of dimethylaminopyridine (DMAP) in dry toluene followed by in situ reaction with different bulky phenols/thiophenols under the same reaction conditions. The structures of the synthesized compounds were confirmed by analytical, IR, multinuclear NMR studies. Their antibacterial and antifungal activities were evaluated against Staphylococcus aureus, Escherichia coli, Aspergillus niger and Fusarium oxysporium, respectively. Some of them showed moderate activity against these microorganisms.
Generation and reactivity of 3‐carbethoxy‐5‐phenyl‐5H,7H‐thiazolo[3,4‐c]oxazol‐4‐ium‐1‐olate
Authors: Pinho e Melo Teresa M. V. D. , Gomes Clara S. B. , Soares Maria I. L. , Gonsalves Antóanio M. d'A Rocha , Paixão José A. , Beja Ana M. , Silva Manuela Ramos 
Published: March 2009

Abstract3‐Carbethoxy‐5‐phenyl‐5H,7H‐thiazolo[3,4‐c]oxazol‐4‐ium‐1‐olate was generated from (2R,4R)‐N‐ethoxyoxalyl‐2‐phenylthiazolidine‐4‐carboxylic acid and its reactivity studied. This münchnone showed low reactivity as dipole although from the reaction with dimethyl acetylenedicarboxylate the corresponding (3R)‐3‐phenyl‐17H,3H‐pyrrolo[1,2‐c]thiazole‐5,6,7‐tricarboxylate could be isolated. The thermolysis of (2R,4R)‐N‐ethoxyoxalyl‐2‐phenylthiazolidine‐4‐carboxylic acid in refluxing acetic anhydride led to the synthesis of N‐(1‐ethoxycarbonyl‐2‐phenylvinyl)‐2‐phenyl‐4‐thioxo‐1,3‐thiazolidine. The structure of methyl (2R,4R)‐N‐ethoxyoxalyl‐2‐phenylthiazoliddine‐4‐carboxylate was determined by X‐ray crystallography.
One‐step synthesis of aminopyrimidines from 5‐Oxo‐4H‐benzopyrans
Authors: Salfrán Esperanza , Seoaneb Carlos , Suárez Margarita , Verdecia Yamila , Alvarez Amaury , Ochoa Estael , Martínez‐Alvarez Roberto , Martín Nazario 
Published: March 2009

AbstractNovel 4‐amino‐6‐aryl‐2‐phenylpyrimidine‐5‐carbonitriles have been prepared in one step procedure from the readily available 4‐aryl‐2‐amino‐3‐cyano‐5,6,7,8‐tetrahydro‐7,7‐dimethyl‐5‐oxo‐4H‐benzopyrans. The mass spectroscopy study under EI conditions shows molecular peaks with high intensity corresponding to the loss of benzonitrile from the C2 position of the pyrimidine ring. Semiempirical (AMI and PM3) and ab initio HF/6–31G* calculations reveal a favored distorted geometry where the three rings are not in the same plane.
Preparation of new N6, 9‐disubstituted 2‐phenyl‐adenines and corresponding 8‐azaadenines.: A feasibility study for application to solid‐phase Synthesis. I
Authors: Biagi Giuliana , Giorgi Irene , Livi Oreste , Pacchini Federica , Scartoni Valerio , Salerni Oreste Leroy 
Published: March 2009

AbstractA suitably substituted pyrimidine 1 was converted to a number of title compounds. Nucleophilic substitu tion involving the chlorine atoms in 1 by treatment with phenylmethanethiol yielded 2 or 3, depending on the reaction temperature. Treatment of 3 with an amine afforded 6‐phenylmethanesulfanyl‐N4‐substituted‐2‐phenyl‐pyrimidine‐4,5‐diamines 4–7. These pyrimidines were converted into 2‐phenylpurines 8–11 and 2‐phenyl‐8‐azapurines 12–14, by treatment with triethyl orthoformate in the presence of hydrochloric acid (or acetic anhydride), or with potassium nitrite and acetic acid respectively. The thioether function on C(6) was then converted into a sulfonyl group by oxidation with m‐chloroperoxybenzoic acid affording purines 15–18 and their 8‐azaanalogs 19–21; these compounds, as crude products, were treated with an amine to yield the corresponding adenines 22–25 or 8‐azaadenines 26–31. All reactions were performed under conditions com patible with the possible use of a thiomethyl resin in place of phenylmethanethiol to bind the pyrimidine ring of 1 to a solid phase.
The synthesis of substituted indazoles via cyclization of various hydrazones in the presence of polyphosphoric acid (PPA)
Authors: Guofu Qiu , Jiangtao Su , Xichun Feng , Lamei Wu , Wenjin Xu , Xianming Hu 
Published: March 2009

AbstractResearch directed toward the discovery of nitric oxide synthase inhibitor led to synthesis of a series of substituted indazoles via the intramolecular cyclization of various hydrazones of substituted acetophenones and benzophenones in the presence of polyphosphoric acid (PPA). The structures of the indazoles were determined by elemental analysis, H nmr, ir, and ms.
Indium‐mediated facile preparation of 2‐(heterocyclic thio)‐1‐(2,3,4‐trimethoxyphenyl)ethanone in aqueous media
Authors: Yang Song , Song Bao‐An , Zhang Hua , Hu De‐Yu , Jin Lin‐Hong , Liu Gang 
Published: March 2009

AbstractAn environmentally benign and efficient process for the preparation of 1‐(2,3,4‐trimethoxyphenyl)‐2‐substituted heterocyclic thio ethanone derivatives was achieved by the reactions of mercapto compounds with 2‐bromo‐1‐(2,3,4‐trimethoxyphenyl)ethanone in water mediated by indium in very high yields. Antifungal activities of the compounds were examined and moderate activity was obtained.
New results on the reactivity of 5,6‐diamino‐4‐hydroxy‐2‐mercaptopyrimidine
Authors: Cosimelli Barbara , Iadanza Manuela , Novellino Ettore , Spisani Raffaella 
Published: March 2009

AbstractThe reaction of 5,6‐diamino‐4‐hydroxy‐2‐mercaptopyrimidine with mono‐ and α,ω‐dihalocompounds has been reinvestigated. Alkyl derivatives of 5‐amino group, not previously described, have been obtained as reaction products. A comparison with the reactivity of 6‐amino‐4‐hydroxy‐2‐mercaptopyrimidine has been also performed.
Synthesis of new non‐symmetrical substituted 7,7′‐bisindolizines by the direct reaction of 4,4′‐bipyridinium‐ylides with dimethyl acetylenedicarboxylate
Authors: Rotaru Alexandru V. , Danac Ramona P. , Druta Ioan D. 
Published: March 2009

AbstractWe report here on the synthesis of some novel non‐symmetrical substituted bisindolizines by 3+2 dipolar cycloaddition reaction. New compounds were prepared by the direct reaction of isolated non‐symmetrical substituted 4,4′‐bipyridinium bisylides with dimethyl acetylenedicarboxy late (DMAD). The obtained compounds can be used as precursors of fluorescent markers in fluorometric analysis.
Spiro‐heterocycles from substituted pyridines, pyrans and thiopyrans
Authors: Padmavathi Venkatapuram , Reddy Boggu Jagan Mohan , Chandra Boreddy , Reddy Obula , Padmaja Adivireddy 
Published: March 2009

AbstractA new class of spiro‐pyrimidines, pyrazoles and isoxazoles are prepared by nucleophilic reaction of 3,5‐diaroyl‐2,6‐diaryl‐piperidine‐4,4‐dicarbonitrile (1), 3,5‐diaroyl‐2,6‐diaryl‐tetrahydropyran‐4,4‐dicarbonitrile (2) and 3,5‐diaroyl‐2,6‐diaryl‐tetrahydrothiopyran‐4,4‐dicarbonitrile (3) with urea, N,N'‐dimethyl urea, thiourea, hydrazine hydrate and hydroxylamine hydrochloride.
Synthesis and structure of some imines containing furoxan ring derived from isosafrole
Authors: Dinh Nguyen Huu , Ly Ngo Thi , Van Le Thi Thanh 
Published: March 2009

AbstractA series of 14 imines containing furoxan and benzene rings has been prepared starting from isosafrole. The structure of reported compounds have been confirmed by elemental analysis, EI MS, UV, IR, and NMR spectroscopy. It is shown that, on treatment with Na2S2O4, the nitro group on the benzene ring was reduced to amino group, but the N→O group of the furoxan ring was not. The 1H‐ and 13C NMR signals are assigned based on their spin‐spin splitting patterns, in some cases, NOESY and HMBC spectra are used. The NOESY spectra indicate that for reported imines, the benzene and the furoxan rings could not be co‐planar; the imine group has E‐configuration.
Synthesis of 3‐(substituted)‐2,4,8,15‐tetroxa‐3‐phosphadispiro[5.2.5]hexadecane‐3‐oxides
Authors: Reddy C. Suresh , Babu Y. Hari , Sankar N. Ravi , Reddy C. Devendranath 
Published: March 2009

AbstractNovel 3‐(substituted)‐2,4,8,15‐tetroxa‐3‐phosphadispiro[5.2.5]hexadecane‐3‐oxides (3‐12) have been synthesized by cyclization of 1,5‐dioxaspiro[5.5]undecande‐3,3‐dimethanol (1) with various substituted aryl phosphorus dichloridates (2) in dry toluene‐THF in the presence of triethylamine at 40‐60 oC. Their molecular structures were determined by ir, nmr and mass spectral studies and were screened for antifungal activity against Curvularia lunata and Aspergillus niger, and antibacterial activity on Staphylococcus aureus and Escherichia coli. Most of them possess significant activity.
A mild, efficient and improved protocol for the friedländer synthesis of quinolines using lewis acidic ionic liquid
Authors: Karthikeyan Ganesan , Perumal Paramasivan T. 
Published: March 2009

AbstractLewis acidic ionic liquid is shown to be for the first time an excellent medium and efficient catalyst for the synthesis of quinolines at room temperature from o‐amino aromatic carbonyls and ketones containing active methylene group.
Total lipid, fatty acid composition and lipid oxidation of Indian white shrimp (Fenneropenaeus indicus) fed diets containing different lipid sources
Authors: Ouraji Hossein , Shabanpour Bahareh , Kenari Abdolmohammad Abedian , Shabani Ali , Nezami Shabanali , Sudagar Mohammad , Faghani Sareh 
Published: March 2009

AbstractBACKGROUND: Seafood is an important constituent of the human diet. In Iran, Indian white shrimp (Fenneropenaeus indicus) is the major cultured shrimp species as a result of market demand, local availability and growth rate. It is mainly reared using commercial feed. The purpose of this study was to evaluate the effects of replacing 50% of the fish oil by vegetable oils in shrimp feed on total lipid, fatty acid composition and lipid oxidation of shrimp muscle.RESULTS: No significant differences in total lipid content (6.1–7.3 g kg−1) were found between edible tissues of shrimp fed different diets. The major fatty acids in shrimp muscle were palmitic, oleic, lionoleic, stearic, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Higher levels of EPA and DHA were observed in muscle of shrimp fed a diet containing fish oil. Oxidative rancidity, measured as thiobarbituric acid reactive substances, for all shrimps did not exceed 0.2 mg malonaldehyde kg−1 muscle tissue, which was low and acceptable.CONCLUSION: This study had shown that the fatty acid composition of feed directly affects the fatty acid composition of Indian white shrimp muscle. Farmed Indian white shrimp can be considered as a species of low fat and shrimp muscle was quite stable to oxidation during storage. Copyright © 2009 Society of Chemical Industry
Inhibition and inactivation evaluation of exogenous glycosidases in wines using p‐nitrophenylglycosides
Authors: Cid Alicia G , Ellenrieder Guillermo 
Published: March 2009

AbstractBACKGROUND: Glycosidases are often used to improve the aroma of wines via hydrolysis of glycosidic precursors. The aim of this work was to develop a method to test activity and stability of these enzymes in wine environments using p‐nitrophenylglycosides, avoiding interference by colored substances.RESULTS: The proposed procedure for determination of glycosidase activity in wines involves quantification of the hydrolysis product p‐nitrophenol by HPLC. The method was applied to compare the inhibition of some commercial glycosidases by red and white wines. It was found that inhibition of a β‐D‐glucosidase by ethanol, glucose and gluconolactone was smaller than that produced by wine. This enzyme was also inhibited by wine fractions rich in phenolic compounds and glycosides. When glycoside fractions were first hydrolyzed, their inhibition was strongly reduced. The stability of glycosidases in red wines was tested, showing a destabilizing effect of β‐glucosidases that was stronger than in white wine.CONCLUSION: The method developed allows measurement of glycosidase activity on p‐nitrophenylglycosides in the presence of colored wine compounds. Comparison of relative glycosidase activity in wines to that in buffer solution under the same conditions can assist in the selection of appropriate aroma‐enhancing enzymes. Copyright © 2009 Society of Chemical Industry
Monthly‐, medium‐, and short‐range flood warning: testing the limits of predictability
Authors: Thielen J. , Bogner K. , Pappenberger F. , Kalas M. , del Medico M. , de Roo A. 
Published: March 2009

AbstractThis paper describes a case study that explores the limits of the predictability of floods, by combining forecasts with multiple spatial and temporal resolutions. Monthly, medium‐ and short range numerical weather prediction (NWP) data are input to the European Flood Alert System for a flood event that affected rivers in Romania in October 2007. The NWP data comprise ensembles and deterministic forecasts of different spatial resolutions and lead times from different weather prediction models. Results are explored in terms of the individual NWP components as well as the ensemble. In this case study, ensembles of monthly weather forecasts contribute only marginally to the early warning, although some indication is given as early as 3 weeks before the event. The 15‐day medium‐range weather forecasts produce early flood warning information 9 to 11 days in advance. As the event draws nearer and is in range to be captured by the higher resolution ensemble forecasts, the spatial extent of the event is forecast with much more precision than with the medium‐range. A novel post‐processing method for the calculation of river discharge is applied to those stations where observations are available, and is able to correct for time‐shifts and to improve the quantitative forecast. The study illustrates how a combination of forecasts and post‐processing improves the lead time for early flood warnings by 2 to 3 days, while remaining reliable also in the short‐range. Copyright © 2009 Royal Meteorological Society
A possible case of an ossifying fibroma in a Late Neolithic population from Portugal
Authors: Silva A. M. , Wasterlain S. N. 
Published: March 2009

AbstractThis paper discusses the differential diagnosis of an unusual bone tumour observed in the right maxilla of one adult calvarium, from the Late Neolithic collective burial of Lapa do Bugio (Sesimbra, Portugal). The differential diagnosis of the lesion gave rise to several possible pathological conditions, namely, ossifying fibroma, fibrous dysplasia, and focal cemento‐osseous dysplasia. Despite the impossibility of performing histological analysis, various macroscopic and radiological aspects lead us to consider ossifying fibroma as the most probable diagnose. This appears to be the earliest reported case of this condition in the osteoarchaeological literature, and adds to the very few palaeopathological case descriptions available for ossifying fibroma. Copyright © 2009 John Wiley & Sons, Ltd.
Hyperbranched cyclic and multicyclic polymers by “a2+b4” polycondensations
Authors: Kricheldorf Hans R. 
Published: March 2009

AbstractAt first, theoretical aspects of “a2+b4” polycondensations (meaning polycondensations of difunctional and tetrafunctional monomers) are discussed and compared with what is known about “a2+b3” polycondensations. The following review of experimental results is subdivided into three sections. First, syntheses of hyperbranched polyethers and polyesters by polycondensations based on equimolar feed ratios will be reported. Second, kinetically controlled (i.e., irreversible) syntheses of multicyclic polymers using equifunctional feed ratios (i.e., a2/b4 ratios of 2:1) will be described. In the third section, syntheses of multicyclic polymers via thermodynamically controlled (reversible) “a2+b4” polycondensations will be discussed. Characteristic for these polycondensations are again equifunctional feed ratios and metal alkoxides as “a2” or “b4” monomers, which catalyze rapid equilibration reactions. Finally, potential applications of the new polymers will shortly be mentioned. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1971–1987, 2009
Iron(III)‐mediated AGET ATRP of styrene using tris(3,6‐dioxaheptyl)amine as a ligand
Authors: Bai Liangjiu , Zhang Lifen , Zhu Jian , Cheng Zhenping , Zhu Xiulin 
Published: March 2009

AbstractA commercially available tris(3,6‐dioxaheptyl)amine (TDA‐1) was used as a novel ligand for activator generated by electron transfer atom transfer radical polymerization (AGET ATRP) of styrene in bulk or solution mediated by iron(III) catalyst in the presence of a limited amount of air. FeCl3·6H2O and (1‐bromoethyl)benzene (PEBr) were used as the catalyst and initiator, respectively; and environmentally benign ascorbic acid (VC) was used as the reducing agent. The polymerizations show the features of “living”/controlled free‐radical polymerizations and well‐defined polystyrenes with molecular weight Mn = 2400–36,500 g/mol and narrow polydispersity (Mw/Mn = 1.11–1.29) were obtained. The “living” feature of the obtained polymer was further confirmed by a chain‐extension experiment. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2002–2008, 2009
Novel aromatic polymers from benzaldehyde and triphenylamine derivatives: Synthesis, electrochromic, and photochemical properties
Authors: Liou Guey‐Sheng , Chang Hui‐Wen , Lin Kai‐Han , Su Yuhlong Oliver 
Published: March 2009

AbstractA series of novel triphenylamine‐based polymers were synthesized from benzaldehyde and triphenylamine derivatives. All the polymers having high molecular weight are readily soluble in many organic solvents and could be solution‐cast into amorphous films. They had glass transition temperatures (Tgs) in the range of 193–217 °C, and 10% weight loss temperatures in excess of 475 °C. Cyclic voltammograms of all polymers showed reversible oxidation redox peaks and Eonset around 0.42–0.90 V, indicating that the polymers are electrochemically active and stable. In addition, all these polymers revealed photochemical characteristics in conformity with their electrochromic characteristics. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2118–2131, 2009
Application of computer‐aided three‐dimensional skull model with rapid prototyping technique in repair of zygomatico‐orbito‐maxillary complex fracture
Authors: Li Wei Zhong , Zhang Mei Chao , Li Shao Ping , Zhang Lei Tao , Huang Yu 
Published: March 2009

AbstractBackgroundWith the advent of CAD/CAM and rapid prototyping (RP), a technical revolution in oral and maxillofacial trauma was promoted to benefit treatment, repair of maxillofacial fractures and reconstruction of maxillofacial defects.MethodsFor a patient with zygomatico‐facial collapse deformity resulting from a zygomatico‐orbito‐maxillary complex (ZOMC) fracture, CT scan data were processed by using Mimics 10.0 for three‐dimensional (3D) reconstruction. The reduction design was aided by 3D virtual imaging and the 3D skull model was reproduced using the RP technique. In line with the design by Mimics, presurgery was performed on the 3D skull model and the semi‐coronal incision was taken for reduction of ZOMC fracture, based on the outcome from the presurgery.ResultsPostoperative CT and images revealed significantly modified zygomatic collapse and zygomatic arch rise and well‐modified facial symmetry.ConclusionsThe CAD/CAM and RP technique is a relatively useful tool that can assist surgeons with reconstruction of the maxillofacial skeleton, especially in repairs of ZOMC fracture. Copyright © 2009 John Wiley & Sons, Ltd.