bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and fluorescence properties of substituted 7‐aminocoumarin‐3‐carboxylate derivatives
Authors: Corrie John E. T. , Munasinghe V. Ranjit N. , Rettig Wolfgang 
Published: March 2009

Abstract4‐Trifluoromethyl‐ or 6‐bromo‐substituted 7‐diethylaminocoumarin‐3‐carboxamide derivatives 2 and 3, each containing a maleimide have been synthesized as potential fluorescent labeling reagents for thiol groups in proteins and their fluorescence properties have been determined. The 4‐trifluoromethyl substituted compound 2 has a significantly greater Stokes shift than the comparable compound lacking this group, but both the new coumarins have low fluorescence quantum yields (ϕf). When a 4‐trifluoromethyl substituent is present, the 3‐carboxamide is unusually labile to hydrolysis. Bromination of ethyl 7‐diethylaminocoumarin‐3‐carboxylate 17 gave the 6‐ and 8‐bromo derivatives 18 and 19 respectively, and also the 8‐bromo‐7‐monoethylamino compound 20. ϕf for the latter compound is 100‐fold greater than for its diethylamino analogue 19. Fluorescence lifetime measurements support an interpretation based on the twisted intramolecular charge transfer (TICT) model to explain these large differences in ϕf.
Synthesis of 2,4‐diaminopyrrolo[2,3‐d]pyrimidines via thermal fischer indolization. Pyrazole formation with ytterbium triflate catalysis
Authors: Bundy Gordon L. , Schwartz Theresa M. , Palmer John R. , Banitt Lee S. , Watt William 
Published: March 2009

AbstractThe high‐yield synthesis of the 2,4‐diaminopyrrolo[2,3‐d] pyrimidine 4 (PNU‐87663) via a Bischler‐like alkylation‐cyclization sequence was reported earlier. We describe herein an alternative synthesis of this potent antioxidant and several analogs based on the thermal Fischer indolization, starting from hydrazino substituted pyrimidines 5 and 13. In several cases where the thermal Fischer indolization failed, attempts to catalyze the reaction with Lewis acids, especially ytterbium triflate, led to the surprising and unprecedented formation of pyrazolo[3,4‐d]pyrimidines, e.g. 1‐methyl‐3‐phenyl‐4,6‐di‐1‐pyrrolidinyl‐1H‐pyrazolo[3,4‐d]pyrimidine (24), with the loss of the elements of methane. Mechanistic details of this transformation remain to be investigated.
Conformationally constrained dipeptides. Obtention of enantiomerically pure 6‐acetamido‐5‐oxo‐1,2,3,5,6,7‐hexahydro‐3‐indolizine carboxylic acid
Authors: Millet Régis , Meulon Emmanuelle , Goossens Laurence , Houssin Raymond , Hénichart Jean‐Pierre , Rigo Benoît 
Published: March 2009

AbstractThe separation of a stereoisomeric mixture of esters 6, and the synthesis of the new enantiomerically pure unsaturated 6,5‐fused bicyclic lactam 2 are described. The key‐step involves trimethylsilyl iodide cleavage, without racemization, of a vinylogous carbamate. The cis N‐ acetylamino acid 2 is a new scaffold for the synthesis of rigid β‐turn mimetics.
Efficient synthesis of 3,5‐functionalized isoxazoles and isoxazolines via 1,3‐dipolar cycloaddition reactions of 1‐propargyl‐ and 1‐allylbenzotriazoles
Authors: Katritzky Alan R. , Button Martin A. C. , Denisenko Sergey N. 
Published: March 2009

Abstract3‐Aryl‐5‐(benzotriazol‐1‐ylmethyl)‐ 10a‐f and 3‐p‐methoxyphenyl‐5‐(α‐benzotriazol‐1‐yl‐α‐ethoxymethyl)‐isoxazole (13) were prepared in high yields by 1,3‐dipolar cycloadditions of 1‐propargyl‐benzotriazole (5) and (α‐ethoxypropargyl)benzotriazole (8), respectively, with nitrite oxides 3a‐f (prepared in situ from benzohydroximoyl chlorides 2a‐f). The benzotriazol‐1‐ylmethyl moiety was further elaborated by sequential lithiation and reaction with aldehydes, alkyl halides and Michael acceptors. Similar 1,3‐cycloadditions using 1‐allylbenzotriazole (6) and 1‐(α‐ethoxyallyl)benzotriazole (7) afforded 3,5‐substituted isoxazolines 11b, f and 12 in excellent yields.
New fused pyrazines. Synthesis of pyrido[3′,2′:4,5]‐thieno[2,3‐e]pyrrolo[1,2‐a]pyrazine derivatives
Authors: El‐Kashef H. S. , El‐Dean A. M. Kamal , Geies A. A. , Lancelot J. C. , Dallemagne P. , Rault S. 
Published: March 2009

AbstractThe synthesis of the title compounds was achieved using the key intermediate ethyl 4,6‐dimethyl‐3‐(pyrrol‐1‐yl)thieno[2,3‐b]pyridine‐2‐ carboxylate 2. This latter compound was obtained via the interaction of the thienopyridine amino ester 1 with 2,5 dimethoxytetrahydrofuran in acidic medium.
Reactivity of N‐benzyl‐3‐nitrophthalimide: A facile access to isoindolo[1,2‐d][3,5]benzothiazocine derivatives
Authors: Chihab‐Eddine Abderrahim , Jilale Abderrahim , Daïch Adam , Decroix Bernard 
Published: March 2009

AbstractA functionalized isoindolo[1,2‐d][3,5]benzothiazocine 2B has been synthesized in three steps from the nitro‐imide derivative 5. The key step of this sequence was the cyclization of the thioglycolic acid derivative 9 under acidic conditions. An evaluation of the reactivity of the imide 5 and the corresponding N‐acyliminium ion toward borohydride reduction, organometallic addition, Meyer‐Schuster rearrangement and intermolecular alkoxylation and thioalkoxylation reactions was reported.
The synthesis and first full structural elucidation of a benzotriazole azo dye
Authors: Graham Duncan , Kennedy Alan R. , Teat Simon J. 
Published: March 2009

AbstractAlthough azo dyes containing benzotriazole are of interest as substrates for surface enhanced resonance Raman scattering, SERRS, little is known of their molecular structure due to their poor crystal growth properties. We recently synthesised a highly crystalline dihydroquinoline via an unusual condensation reaction and we report herein that the azo‐benzotriazole dye subsequently formed was sufficiently crystalline to allow structural elucidation using synchroton radiation. It was found that this benzotriazole dye exists as the unexpected 6‐isomer and the structure of the dihydroquinoline moiety changes markedly on coupling due to increased delocalisation.
Synthesis of 1‐substituted [1,2,3]triazolo[4,5‐d]pyridazines as precursors for novel tetraazapentalene derivatives
Authors: Ramanaiah K. C. V. , Stevens Edwin D. , Trudell Mark L. , Pagoria Philip F. 
Published: March 2009

AbstractA series of 1‐substituted 4,5‐diformyl‐[1,2,3]triazole derivatives were prepared by 1,3‐dipolar cyclo‐addition of aryl azides with acetylene dicarboxaldehyde mono‐diethylacetal. The triazoles were readily converted into 1‐substituted [1,2,3]triazolo[4,5‐d]pyridazines in good yields. The 1‐(2‐nitrophenyl)‐[1,2,3]triazolo[4,5‐d]pyridazine was found to be a useful intermediate for the generation of the novel 5H‐benzo[1,2,3]triazolo[1′,2′:1,2]triazolo[4,5‐d]pyridazin‐6‐ium inner salt ring system.
New routes to the synthesis of pyridazinone, ethoxypyridine, pyrazole and pyrazolo[1,5‐a]pyrimidine derivatives incorporating a benzotriazole moiety
Authors: Al‐Omran Fatima , Abd El‐Hay Osama Yousef , Abou El‐Khair Adel 
Published: March 2009

AbstractA new approach to the synthesis of pyridazinone, ethoxypyridine, pyrazole and 7‐aminopyrazolo‐[1,5‐a]pyrimidine derivatives. The structure of the newly synthesized compounds was elucidated by elemental analyses, ir, 1H nmr spectra and in some cases by 13C nmr investigations.
A new diaza‐18‐crown‐6 ligand containing two quinolin‐8‐ylmethyl side arms: Crystal structures and characterization of the ligand, the protonated ligand and its mononuclear barium(II) and dinuclear copper(II) complexes
Authors: Dalley N. Kent , Xue Guoping , Bradshaw Jerald S. , Zhang Xian Xin , Harrison Roger G. , Savage Paul B. , Krakowiak Krzysztof E. , Izatt Reed M. 
Published: March 2009

AbstractA new 7,16‐bis(quinolin‐8‐ylmethyl)‐1,4,10,13‐tetraoxa‐7,16‐diazacyclooctadecane ligand, L, has been prepared and its crystal structure reported. In addition, the structure of the protonated ligand H2L has been determined. H2L is of interest because of interatomic interactions between the ligand and perchlorate ions. The mononuclear Ba(II) (BaL), and dinuclear Cu(II) (Cu2L) complexes of L have been prepared and their crystal structures determined. Stability constants and other thermodynamic data valid in methanol at 23 or 25° for these and several other complexes of L have been obtained. Among the metal ions studied, L forms the most stable complex with Ba2+. In addition, L selectively binds Cu2+ over Ni2+ by about 3 orders of magnitude. Some of the complexes have been studied using nmr and uv‐vis spectroscopic techniques. Crystal data are given for L, space group, P21c, a = 8.8325(14) Å, b = 13.808(3) Å, c = 13.310(3) Å; β = 94.72(2)° Z=2, R = 0.0727; for H2L, space group, P21/c, a = 14.685(3) Å, b = 15.035(6) Å, c = 17.369(4) Å, β = 90.366(12)°, Z = 4, R = 0.0781; for BaL, space group, Pbcn, a = 17.314(3) Å, b = 9.539(2) Å, c = 22.081(3) Å, Z = 4, R = 0.0354; and for Cu2L, space group, Cc, a = 19.762(2) Å, b = 14.413(2) Å, c = 14.935(2) Å, β = 98.753(12)°, Z = 4, R = 0.0564. Cu2+ forms a hydroxo‐bridged dinuclear complex with L while Ba2+ forms a mononuclear complex with L in which its two side arms are not involved in complexation.
Synthesis of functionalized cyclic enamines from lithium alkylphenyl sulfones and N‐carbo‐tert‐butoxy lactams
Authors: Arias Luis A. , Arbelo David , Alzérreca Arnaldo , Prieto José A. 
Published: March 2009

AbstractAlkylphenyl sulfones 3 are appropriate synthons for the synthesis of 2‐phenylsulfonyl alkylidene pyrro‐lidine or piperidine derivatives 1 in good to moderate yields. The lithium alkyl sulfones 4 are first reacted with the desired protected lactams and then subjected to acidic methanolysis to afford the unusual enam‐ines 1a‐e. NMR studies (COSY 1H‐1H, COSY 1H‐13C, NOE) showed the Z enamines to exist in a dynamic equilibrium with the corresponding imines 2. The stereochemistry of the described compounds was confirmed by molecular calculations.
Synthesis and structural analysis of 5‐cyanodihydropyrazolo[3,4‐b]pyridines
Authors: Quiroga Jairo , Cruz Silvia , Insuasty Braulio , Abonia Rodrigo , Cobo Justo , Sánchez Adolfo , Nogueras Manuel , Low John N. 
Published: March 2009

AbstractSeveral new 3‐aryl‐5‐cyanopyrazolo[3,4‐b]pyridines were easily prepared from 3‐amino‐5‐arylpyrazoles and α‐cyanochalcones. Structural analysis using NMR solution studies revealed the 2H‐tautomers as the preferred tautomer in solution (DMSO‐d6). X‐ray diffraction confirmed the 2H‐tautomers as the unique tau‐tomer species in the crystalline state as well. Geometry optimization of 1H and 2H‐tautomers at semi‐empirical levels (AM1, MINDO/3) were performed, indicating that in all cases the 2H‐tautomers are more stable than the corresponding 1H‐tautomers.
Pyridazines 92. Synthesis of dialkyldipyridazinodiazepinones as potential HIV‐1 reverse transcriptase inhibitors
Authors: Heinisch Gottfried , Matuszczak Barbara , Spielmann Elisabeth , Witvrouw Myriam , Pannecouque Christophe , De Clercq Erik 
Published: March 2009

AbstractTwo methods for the preparation of dialkylsubstituted dipyridazino[4,3‐b:3′,4′‐e][1,4]diazepinones and dipyridazino[3,4‐b:3′,4′‐e][1,4]diazepinones are reported. The new compounds were evaluated for their inhibitory effects against the replication of human immunodeficiency virus [HIV‐1(IIIB) and HIV‐2(ROD)] in MT‐4 cells.
Oxidation of 7,8‐diaminotheophylline with lead tetraacetate and reaction of the oxidation product, 6‐cyanoimino‐5‐diazo‐1,3‐dimethylpyrimidine‐2,4‐dione with alcohols or amines
Authors: Ueda Taisei , Yatsuzuka Naoyoshi , Nagai Shin‐Ichi , Okada Kumiko , Takeichi Emi , Segi Hiromi , Sakakibara Jinsaku 
Published: March 2009

AbstractOxidation of 7,8‐diaminotheophylline (1) with lead tetraacetate in refluxing toluene gave a mixture of 3‐amino‐5,7‐dimethylpyrimido[4,5‐e][1,2,4]triazine‐6,8‐dione (2) and 6‐cyanoimino‐5‐diazo‐1,3‐dimethylpyrimidine‐2,4‐dione (4). The latter was transformed to 2 by the reaction with 1‐propanethiol in quantitative yield. The reaction of 4 with methanol, ethanol and 1‐propanol in the presence of rhodium (II) acetate gave 5‐alkoxy‐6‐(2‐alkyl‐3‐isoureido)‐1,3‐dimethylpyrimidine‐2,4‐diones (7a‐c). A similar reaction of 4 with alkylamines such as n‐propylamine, n‐butylamine, isobutylamine and n‐hexylamine gave a mixture of 7‐alkyl‐8‐aminotheophyllines (8a‐d) and (5‐alkylamino‐1,3‐dimethyl‐2,4‐dioxopyrimidin‐6‐yl)cyanamides (9a‐d).
Design and synthesis of some new pyranoxanthenones with cytotoxic activity
Authors: Ghirtis Konstantinos , Pouli Nicole , Marakos Panagiotis , Skaltsounis Alexios‐Leandros , Leonce Stephane , Atassi Ghanem , Caignard Daniel H. 
Published: March 2009

AbstractAs part of a research program directed towards the design and synthesis of pyranoxanthones structurally related to acronycine, we present here the synthesis and cytotoxic activity of the pyranoxanthones 3 and 4 (X= H, Br; R= H, OMe; R'= H, Ac). Some of these compounds inhibit L1210 cell proliferation.
Bifunctional coumarin derivatives in solution and solid phase synthesis of fluorogenic enzyme substrates
Authors: Charitos Christos , Kokotos George , Tzougraki Chryssa 
Published: March 2009

AbstractThe use of the fluorescent bifunctional compounds 7‐amino‐4‐coumarinyl‐acetic acid 1, 7‐hydroxy‐4‐coumarinyl‐acetic acid 2 and ethyl 7‐amino‐4‐coumarinyl‐acetate 3 in solution and solid phase synthesis of fluorogenic enzyme substrates was examined. The intramolecularly quenched fluorogenic substrate N‐(7‐amino‐4‐coumarinyl‐acetyl)‐L‐phenylalanyl‐p‐nitroanilide 5, and the fluorogenic one ethyl 7‐(glutaryl‐L‐phenylalanilamido)‐4‐coumarinyl‐acetate 8, both suitable for chymotrypsin and/or chymotrypsin like enzymes determination, were prepared in solution. The substrates 7‐oleyloxy‐4‐coumarinyl‐acetic acid 13 and 7‐palmitoyloxy‐4‐coumarinyl‐acetic acid 14, suitable for the enzymatic study of lipases, were prepared by solid phase technique using 2‐chloro‐chlorotrityl‐resin. The study of the fluorescence properties of the fluorophores 1, 2, 3, and substrates 5, 8,13,14 showed that the examined bifunctional coumarin derivatives are suitable markers for solution and solid phase synthesis of fluorogenic enzyme substrates.
Synthesis of hyperolactones A and C
Authors: Ueki Toshihiko , Doe Matsumi , Morimoto Yoshiki , Kinoshita Takamasa , Tanaka Rika , Yoshihara Kazuo 
Published: March 2009

AbstractHyperolactones A (1) and C (3) have been synthesized starting from (S)‐malic acid by a straightforward route. The unique spirolactone skeleton was efficiently constructed by one‐pot reaction as a key step. The absolute stereochemistry of hyperolactones was unambiguously established by this synthesis.
N‐bromosuccinimide reactions of some heterocycles in the presence or absence of water: An overview of ring versus side chain bromination for the synthesis of important brominated heterocyclic synthons
Authors: Goswami Shyamaprosad , Ghosh Kumaresh , Mukherjee Reshmi , Adak Avijit Kumar , Mahapatra Ajit Kumar 
Published: March 2009

AbstractReactions of various heterocycles 1–6 with N‐bromosuccinimide in the presence or absence of water have been studied for side chain versus ring bromination to afford some new and important heterocyclic synthons. Interestingly, the N‐bromosuccinimide reaction in the presence of perchloric acid, a new condition, affords exclusively the new dibromo aminopicoline 1f, which is not obtained by other presently studied methods.
New heterocycles with cycloamidine substructure and their ringtransformation reactions with acetylene dicarboxylic ester
Authors: Billot Thomas , Beckert Rainer , Döring Manfred , Wuckelt Jörg , Fehling Peer , Görls Helmar 
Published: March 2009

AbstractThe synthesis of pyrido[2,1‐c]‐1,2,4‐triazines 6, pyrido[1,2‐b]‐1,2,4‐triazines 7 and pyrido[1,2‐b]pyri‐dazines 8 respectively by cycloacylation of derivatives of pyridine with imidoylchlorides of type 2 is described. The heterocycles of type 6 as well as of type 7 can be ring‐transformed with dimethyl acetylenedicarboxylate. In contrast to pyrido[1,2‐a]pyrazines 1, a complex reaction including cleavage of the acetylene subunit takes place. Starting from compound 6a, the pyrrolo[2,3‐d]imidazole 11a could be isolated from a mixture of unidentified by‐products, whereas derivatives 7 gave nearly quantitatively the tricyclic products of type 12.
Synthesis and antimicrobial activity of 2‐substituted‐2,3‐dihydro‐5‐propoxy‐1H‐1,3,2‐benzodiazaphosphole 2‐Oxides
Authors: Venugopal M. , Reddy B. Sankar , Reddy C. Devendranath , Berlin K. D. 
Published: March 2009

AbstractSeveral 2‐alkylcarbamato/thiocarbamato/aryloxy/trichloromethyl‐2,3‐dihydro‐5‐propoxy‐1H‐1,3,2‐benzodiazaphosphole 2‐oxides (4 and 6) were synthesised by reacting 4‐propoxy‐o‐phenylenediamine (1) with various N‐dichlorophosphinyl carbamates (3), aryl phosphorodichloridates (5a‐f) and trichloromethyl phosphonic dichloride (5g) in the presence of triethylamine at 45‐65 °C. Their ir, 1H, 13C, 31P nmr and mass spectral data are discussed. The compounds were screened for antifungal activity against Curvularia lunata and Aspergillus niger and for antibacterial activity against Bacillus subtilis and Escherichia coli. Most of these compounds exhibited moderate activity in the assays.
Facile synthesis of mono and dibenzo N,N'‐disubstituted diaza 18‐crown‐6 derivatives
Authors: Topal Giray , Demirel Nadir , Toğrul Mahmut , Turgut Yilmaz , Hoşgören Halil 
Published: March 2009

AbstractThis study represents a facile synthesis of building blocks (1–3) of crown ethers and amine precoursers (4a‐d). The study also involves synthesis of mono and dibenzo N, N‐disubstituted diaza 18‐crown‐6 derivatives with high yield without chromatographic purification and high vacuum distillation. The complex ability of host the ethers was evaluated in terms of structural modification.
Ru catalyzed cyclodimerization of bis(2‐thienyl)acetylene and bis(3‐thienyl)acetylene. Synthesis properties of 4,5,6‐tris(2‐thienyl)benzo(b)thiophene and 5,6,7‐tris(3‐thienyl)benzo[b]thiophene
Authors: Lu Ping , Li Jian , Weber William P. , Cai Guoping 
Published: March 2009

AbstractActivated dihydridocarbonyltris(triphenylphosphine)ruthenium catalyzes the cyclodimerization of both bis(2‐thienyl)acetylene and bis(3‐thienyl)acetylene to yield, respectively, 4,5,6‐tris(2′‐thienyl)‐benzo[b]thiophene and 5,6,7‐tris(3′‐thienyl)benzo[b]thiophene. These fluoresce in the blue. Both undergo irreversible one electron oxidation at & sim1.1 mV versus Ag/Ag+ electrode, consistent with oxidation of the benzo[b]thiophene nuclei rather than the substituent thiophene rings.
Reaction of 2,5‐dimethylpyrroles with quinones. Synthesis of new pyrrolylquinones
Authors: Lion Dyes Claude , Baudry Richard , Hedayatullah Mir , Da Conceiçlato Louis , Genard Sylvie , Maignan Jean 
Published: March 2009

AbstractThe reaction of 1,4‐naphthoquinone (1) with 2,5‐dimethylpyrroles (7a‐7d) gives only 3‐(1,4‐naphtho‐quinonyl)‐2,5‐dimethylpyrroles. Extending the reaction to other quinones: 5‐hydroxy‐1,4‐naphthoquinone (2), 1,2‐naphthoquinone (3), quinoline‐5,8‐dione (4) and quinoxaline‐5,8‐dione (5), of which nothing was known, allows the synthesis of new pyrrolylquinones.
Thermal cyclization of 3‐azido‐2‐phenyl‐indan‐l‐one to 5h‐indeno[1,2‐b]indol‐10‐one
Authors: Stadlbauer Wolfgang , Fischer Michaela 
Published: March 2009

Abstract3‐Azido‐2‐phenylindan‐1‐one (4), which was obtained from 3‐chloro‐2‐phenylindan‐1‐one (3), cyclizes on thermolysis to 5H‐indeno[1,2‐b]indol‐10‐one (5). Reaction of 3‐azido‐2‐phenylindan‐1‐one (4) with triphenylphosphane gives 2‐phenyl‐3‐(triphenylphosphoranylideneamino)‐indan‐1‐one (6), which can be hydrolyzed to 3‐amino‐2‐phenylindan‐1‐one (7). Attempts to perform a similar cyclization sequence with 3‐chloro‐2‐pyridylindan‐1‐ones failed.
Synthesis and characterization of some heterocyclic derivatives by cyclization of carbohydrate thiosemicarbazone ‐ part III
Authors: Alho M. A. Martins , D'Accorso N. B. 
Published: March 2009

AbstractSynthesis of (3′R) 2‐acetamido‐4‐N‐acetyl‐3′‐spiro‐[1,2′:5′,6′‐di‐O‐isopropylidene‐α‐D‐glucofuranosyl]‐1,3,4‐thiadiazoline diastereomerically pure is described. We report the physical and spectroscopic characterization of the new heterocyclic compound as well as its immediate precursors. We discuss also the possibilities for cyclization and established the stereochemistry of the new stereogenic center.
Synthesis and characterization of 1‐methyl‐2,4,5‐trinitroimidazole (MTNI)
Authors: Cho Jin Rai , Kim Kwang Joo , Cho Soo Gyeong , Kim Jeong Kook 
Published: March 2009

AbstractWe have reinvestigated the synthesis of 1‐methyl‐2,4,5‐trinitroimidazole (MTNI; 1), and further characterized its physical properties. It is a promising candidate as an insensitive high explosive. Compound 1 was synthesized from the imidazole (2), via a 5‐step sequence of reactions, and subjected to various sensitivity tests for explosives. The structure of 1 was characterized by X‐ray diffraction. The crystal is orthorhombic; C4H3N5O6, M = 217.11, Z = 8, Pca21, a = 8.6183(6) Å, b = 17.7119(12) Å, c = 10.6873(7) Å, V = 1631.38(19) Å3, Dc = 1.768 g/cm3. The structure was refined to R = 0.0284 for 3201 independent reflections with I > 2σ(I). The molecular structures calculated by high levels of ab initio and density functional theories were in good agreement with those observed by X‐ray experiment. According to our preliminary sensitivity tests, 1 was characterized to be intermediate in sensitivity between RDX and TNT. The explosive performances were evaluated theoretically, and were found to be comparable to those of RDX. In addition, owing to its low melting point (82 °C), 1 is believed to be an excellent candidate for inclusion in melt‐castable explosives, and may lead to increased explosive power.
A synthetic pathway to obtain heterocyclic derivatives containing isoxazole and tetrazole rings joined by a carbohydrate tether
Authors: Esperón María F. Martinez , Fascio Mirta L. , D'Accorso N. B. 
Published: March 2009

AbstractA synthetic route to obtain compounds with two different heterocycles, such as isoxazole and tetrazole rings, in the same molecule from carbohydrate derivatives using 1,3‐dipolar cycloaddition is described. The new compounds involved in this synthesis are physically and spectroscopically characterized.
Synthesis and characterization of some N‐mannich bases of [1,2,3]triazoloquinolines
Authors: Ferlin Maria Grazia , Chiarelotto Gianfranco , Castagliuolo Ignazio 
Published: March 2009

AbstractSome novel N‐Mannich bases of [1,2,3]‐triazolo[4,5‐f] and [4,5‐h]quinolines were synthesized following the classical experimental procedure for Mannich base preparation: triazoloquinoline with formaldehyde and secondary amine. Tricyclic nuclei were obtained starting from two protected isomeric amino‐quinolines, which were nitrated, reduced and diazotated. Two N‐anilinomethyltriazoloquinolines were also synthesized via the N‐hydroxymethyl intermediate.
Studies on the chemistry of thienoannelated O,N‐ and S,N‐containing heterocycles. 24 [1]. Synthesis of imidazo[1,5‐d]thieno[2,3‐b][1,4]‐thiazine derivatives as potential receptor ligands
Authors: Erker Thomas , Handler Norbert 
Published: March 2009

AbstractA facile synthesis of the imidazo[1,5‐d]thieno[2,3‐b][1,4]thiazine ring system is described. Reaction of 6‐benzyl‐2,3‐dihydro‐1H‐thieno[2,3‐b][1,4]thiazine‐2‐one (1) with potassium tert‐butoxide and diethylchlorophosphate gave intermediate 2 which resulted in the disired ring system after adding the corresponding isocyanides and potassium tert‐butoxide.