bluuebunny/crossref_metadata_2025_split huggingface dataset:
Voltammetric behaviour of heterocyclic systems. Pyridyl‐substituted benzimidazoles, benzoxazoles and benzothiazoles
Authors: Savarino P. , Viscardi G. , Quagliotto P. , Perracino P. , Barni E. 
Published: April 2009

AbstractThe voltammetric properties, measured at a dropping mercury electrode, have been studied for a series of 18 pyridyl‐substituted heterocyclic bases [benzimidazoles, benzoxazoles and benzothiazoles]. The corresponding quarternary salts, obtained by reaction with methyl iodide, were also studied. The reduction potential was found to be dependent on the nature of the benzimidazole, benzoxazole or benzothiazole moiety and on its position on the pyridine ring as well as on the presence of a positive charge. The reversibility of the voltammetric waves was found to be function of the system structure. The effects of proton donors on the voltammetric behaviour of the bases was also investigated.
Tandem rearrangement involving a β‐hydroxysulfoxide and cyclization processes toward the 1‐benzenesulfonyl‐5‐benzenethio‐1,2,2a,3,4,5‐hexahydrobenz[c,d]indole oxygenated at the 4‐position
Authors: Stamos Ioannis K. 
Published: April 2009

AbstractTreatment of compound 4 with trifluoroacetic anhydride under reflux in chlorobenzene underwent a tandem rearrangement to produce compound 5. When the acetylated derivative of 4, was treated with trifluoroacetic anhydride in the presence of Lewis acids produced two cis cyclized conformers 7a and 7b, presumably through the intermediate B.
Unusual nitration of substituted 7‐amino‐1,8‐naphthyridine in the synthesis of compounds with antiplatelet activity
Authors: Ferrarini Pier Luigi , Mori Claudio , Badawneh Muwaffag , Manera Clementina , Martinelli Adriano , Romagnoli Federico , Saccomanni Giuseppe , Miceli Mauro 
Published: April 2009

AbstractSeveral 1,8‐naphthyridine derivatives have been diazotizated to obtain the corresponding hydroxy derivatives or mixture of hydroxy and hydroxy nitro derivatives. The respective amounts of hydroxy and hydroxy nitro derivatives depends on the nature of the substituents, on their position on the naphthyridine nucleus, on the amount of sodium nitrite and on the reaction temperature. A study of the electronic density of some molecules suggests a possible explanation of the effects induced by the nature of the substituents and of their position. Some of the compounds were tested for their ability to inhibit human platelet aggregation in vitro induced by arachidonic acid. Only compound 26 showed interesting antiplatelet activity.
Synthesis of new indoyl‐1,3,4‐oxadiazole and oxadiazine derivatives. Potential monoamine oxidase inhibitor activity
Authors: Pérez Silvia , Lasheras Berta , Oset Carmen , Monge Antonio 
Published: April 2009

AbstractNew indolyl‐1,3,4‐oxadiazole and oxadiazine derivatives were prepared as reversible monoamine oxidase inhibitors. The compound 5‐(3‐methylindolyl)‐1,3,4‐oxadiazol‐2(3H)one was shown to be a good monoamine oxidase B inhibitor.
Syntheses of substituted 2‐(l‐methyl‐2‐imidazolyl)quinolines
Authors: Khazan Minoo , Hadizadeh Farzin , Shafiee Abbas 
Published: April 2009

AbstractReaction of methyllithium with 1‐methy1‐2‐imidazolecarboxaldehyde afforded the corresponding alcohol 2. Oxidation of compound 2 with manganese dioxide gave 2‐acety1‐1‐methylimidazole (3). Using compound 3 and substituted isatins 4, the corresponding quinoline‐4‐carboxylic acids (5) were prepared. The reaction of acid imidazolides of 5 with appropriate amines yielded the amides 6. Carbamic acid esters 10 were prepared by the Curtius rearrangement in good yield. Substituted quinolin‐4‐amines 13 were obtained by the acid hydrolysis of compound 10 (R1 = t‐Bu). Alkylation of amines 13 with diakylaminoalkyl chlorides gave compounds 14.
The preparation of N‐(1H‐pyrazol‐3‐yl)arylamides and 1H‐pyrazol‐3‐amines from polylithiated C(α),N‐thiosemicarbazones and C(α),N‐semicarbazones
Authors: Beam Charles F. , Davis Sharon E. , Cordray Tracy L. , Chan Kam W. , Kassis Camille M. , Davis Joanna G. Freeman , Latham G. Mark , Guion Tina S. , Hildebran Karen C. , Church A. Cameron , Koller Madlene U. , Metz Clyde R. , Pennington William T. , Schey Kevin L. 
Published: April 2009

AbstractC(α),N‐Thiosemicarbazones or C(α),N‐semicarbazones were polylithiated with excess lithium diiso‐propylamide, and the resulting cyclized intermediates were condensed with aromatic esters to afford N‐(1H‐pyrazol‐3‐yl)arylamides. The polylithiated intermediates were also quenched with aqueous acid to give 5‐substituted, 1H‐pyrazol‐3‐amines.
Synthesis of 2,3‐dihydropyrido‐ and 2,3‐dihydropyrimido‐[1,4]diazepines from triaminopyridine and triaminopyrimidine
Authors: Insuasty Braulio , Perez Alfredo , Valencia John , Quiroga Jairo 
Published: April 2009

AbstractThe reaction of 2,3,6‐triaminopyridine 1 and 4,5,6‐triaminopyrimidine 2 with one equivalent of the chal‐cones 3, in acetic acid, leads to the formation of the 8‐amino‐2,3‐dihydro‐1H‐pyrido[2,3‐b][1,4]diazepine and 6‐amino‐2,3‐dihydro‐1H‐pyrimido[4,5‐b][1,4]diazepine derivatives 4 and 5. The products were characterized by NMR techniques such as 13C, 1H, and DEPT including selective 13C{1H} decoupling experiments.
Synthesis of optically active β‐lactams by the reaction of 2‐acyl‐3‐phenyl‐l‐menthopyrazoles with CN compounds
Authors: Kashima Choji , Fukusaka Kiyoshi , Takahashi Katsumi 
Published: April 2009

AbstractThe reaction of 1‐acyl‐3,5‐dimethylpyrazoles 1 with CN compounds was kinetically controlled with syn stereoselectivity through a lithium enolate intermediate using lithium diisopropylamide. In contrast, the anti stereoselective reaction of 1 was caused by the action of diisopropylethylamine in the presence of magnesium bromide under the thermodynamic control. Reaction of 2‐acyl‐3‐phenyl‐l‐menthopyrazoles 12 with CN compounds was observed in higher chemical and optical yields with the predominant 2′S configuration. An especially diastereomerically pure product was isolated in the reaction of 2‐propanoyl‐3‐phenyl‐l‐menthopyrazole (12a) with N‐benzylidene‐4‐toluenesulfonamide (2). The products from N‐acyl‐pyrazoles and CN compounds were further cyclized into β‐lactams directly or with short conversion steps.
Chemistry of functionalized benzazepines. 5. Synthesis and chemical transformation of the 1,2,4,5‐tetrahydrospiro‐[3H‐2‐benzazepine‐3,1′‐cycloalkanes]
Authors: Kouznetsov Vladimir , Alirio Palma R. , Salas Sandra , Vargas Leonor Y. , Martinez Jairo René , Zubkov Fedor , Varlamov Alexei 
Published: April 2009

AbstractThe synthesis of new spiro derivatives of tetrahydro‐2‐benzazepine was accomplished and their nitration, bromination, allylation, acetylation, formylation and oxidation reactions were studied. Nitration and bromi‐nation of 5‐methyl(1,5‐dimethyl)‐1,2,4,5‐tetrahydrospiro[3H‐2‐benzazepine‐3,1‐cycloalkane] took place regioselectively on position C‐8 of the phenyl ring. A nitrone was obtained for the first time in the title series. The structures of the compounds were established by ir and nmr spcctroscopy.
Synthesis of 3,5‐disubstituted 1‐amino‐1,3,5‐triazine‐2,4,6‐triones (or 1‐aminocyanurates) by cyclic transformation of 1,3,4‐oxadiazol‐2(3H)‐one derivatives
Authors: Chau François , Malanda Jean‐Claude , Milcent René 
Published: April 2009

AbstractThe 5‐aryl(or methyl)‐3‐phenylcarbamoyl‐1,3,4‐oxadiazol‐2(3H)‐ones 2, in the presence of sodium hydride in anhydrous dimethylformamide, were transformed into 1‐benzamido(or acetamido)‐3,5‐diphenyl‐1,3,5‐triazine‐2,4,6‐trione derivatives 7 in poor yields. However, compounds 7 were obtained in better yields when the sodium salts of 5‐aryl(or methyl)‐1,3,4‐oxadiazol‐2(3H)‐ones 1 were treated with two equivalents of aryl(or ethyl)isocyanates. Acidic hydrolysis of 1‐acetamido‐3,5‐diphenyl‐1,3,5‐triazine‐2,4,6‐trione (7i) provided the corresponding free N‐amino derivative 9. Nitrous deamination of 9 gave the known 3,5‐diphenyl‐1,3,5‐triazine‐2,4,6‐trione (11). This cyclic transformation is the first one to be reported providing 1,3,5‐triazine‐2,4,6‐trione derivatives.
Studies on isoxazole and pyrazole formation by the reaction of trifluoromethyl‐substituted anilines with oxime and hydrazone dianions
Authors: Strekowski Lucjan , Lin Shou‐Yuan 
Published: April 2009

Abstract5‐(2‐Aminophenyl)isoxazoles are obtained in good yields by the reaction of 2‐(trifluoromethyl)aniline with dilithio derivatives of oximes of acetone, 3‐pentanone, propiophenone, and cyclohexanone. An analogous synthesis of a substituted isoxazole from 4‐(trifluoromethyl)aniline and 3‐pentanone oxime and the synthesis of a substituted pyrazole from 2‐(trifluoromethyl)aniline and 3‐pentanone hydrazone are less efficient.
Synthesis of potential metabolites of the brain imaging agents methyl (1R,2S,3S,5S)‐3‐(4‐Iodophenyl)‐8‐alkyl‐8‐azabicyclo[3.2.1]octane‐2‐carboxylate
Authors: Andersen Annette , Wang Shaoyin , Thompson Robert D. , Neumeyer John L. 
Published: April 2009

AbstractThe synthesis of potential hydroxy metabolites of the brain imaging agents methyl (1R,2S,3S,5S)‐3‐(4‐iodophenyl)‐8‐methyl‐8‐azabicyclo[3.2.1]octane‐2‐carboxylate and methyl (1R,2S,3S,5S)‐3‐(4‐iodophenyl)‐8‐(3‐fluoropropyl)‐8‐azabicyclo[3.2.1]octane‐2‐carboxylate are reported. The nitration of iodophenyltropanes 1 or 2 with nitronium tetrafluoroborate afforded the nitro compounds 3 or 4 which were reduced with iron powder to the corresponding amino compounds 5 and 6. The final hydroxylated products 7 and 8 were obtained via a modified Sandmeyer reaction.
Reactions of O‐methyl o‐quinone monoximes with methyl‐, methylene‐ and methine‐ substituted aromatic compounds. Synthesis of benzo[d]oxazole and 1,4‐benzoxazine derivatives
Authors: Nicolaides Demetrios N. , Awad R. Wajih , Papageorgiou Georgios K. , Kojanni Efthalia , Tsoleridis Constantinos A. 
Published: April 2009

AbstractO‐Methyl o‐quinone monoxime 1 reacts thermally with compounds 2a‐d or 6a,b or 7a,b to give mainly the corresponding 2‐substituted phenanthroxazoles 3a‐c and 8. The reaction of 1 with aromatic methylene compounds lOa‐c affords the ketones 13a‐c in moderate to high yields. Similar products are also obtained from the reaction of monoximes 15a,b with some of the above reactants. The unexpected products 5 and 20 are obtained from the reaction of 1 with 2‐methylimidazole (2d) and with phenyloxirane (19) respectively, while the 4H‐1,4‐oxazine derivative 23 is obtained from the reaction of 1 with indene (21).
A new approach for the synthesis of some 1,4‐benzoxathiin 4,4‐dioxide derivatives
Authors: Fan Ai‐Long , Cao Song , Zhang Zheng 
Published: April 2009

AbstractA series of 1,4‐benzoxathiin 4,4‐dioxide derivatives have been prepared by a new synthetic route. The reactions of 2‐chloro‐4‐nitrobenzenethiol 1 with l‐aryl‐2‐chloroethanones 2 in the presence of sodium hydroxide give l‐aryl‐2‐(2‐chloro‐4‐nitrophenylthio)ethanones 3 which on oxidation with 30% aqueous hydrogen peroxide afford l‐aryl‐2‐(2‐chloro‐4‐nitrophenylsulfonyl)ethanones 4. By the reactions of compounds 4 with 2‐[3 or 4‐(bromomethyl)phenyl]benzoxazole in the potassium carbonate, triethylbenzyl‐ammonium chloride and dimethylformamide system, 2‐aryl‐3‐arylmethyl‐7‐nitro‐1,4‐benzoxathiin 4,4‐dioxides 5 or 6 are obtained via a tandem alkylation‐cyclization process.
Nonclassical 5‐substituted tetrahydroquinazolines as potential inhibitors of thymidylate synthase
Authors: Gangjee Aleem , Vasudevant Anil , Kisliuk Roy L. 
Published: April 2009

AbstractClassical inhibitors of thymidylate synthase such as Nl0‐propargyl‐5,8‐dideazafolic acid (1), N‐(5‐[N‐(3,4‐dihydro‐2‐methyl‐4‐oxoquinazolin‐6‐ylmethyl)‐N‐methylamino]‐2‐thenoyl)‐L‐glutamic acid (ZD1694, 2) and N‐[2‐amino‐4‐oxo‐3,4‐dihydro(pyrrolo[2,3‐d]pyrintidin‐5‐yl)ethylbenzoyl]‐L‐glutamic acid (LY231514, 3) while potent, suffer from a number of potential disadvantages, such as impaired uptake due to an alteration of the active transport system required for their cellular uptake, as well as formation of long acting, non‐effluxing polyglutamates via the action of folylpolyglutamate synthetase, which are responsible for toxicity. To overcome some of the disadvantages of classical inhibitors, there has been considerable interest in the synthesis and evaluation of nonclassical thymidylate synthase inhibitors, which could enter cells via passive diffusion. In an attempt to elucidate the role of saturation of the B‐ring of non‐classical, quinazoline antifolate inhibitors of thymidylate synthase, analogues 7‐17 were designed. Analogues 13‐17 which contain a methyl group at the 7‐position, were synthesized in an attempt to align the methyl group in an orientation which allows interaction with tryptophan‐80 in the active site of thymidylate synthase. The synthesis of these analogues was achieved via the reaction of guanidine with the appropriately substituted cyclohexanone‐ketoester. These ketoesters were in turn synthesized via a Michael addition of the appropriate thiophenol with 2‐carbethoxycyclohexen‐1‐one or 5‐methyl‐2‐carbethoxycyclo‐hexen‐1‐one to afford a mixture of diastereomers. The most inhibitory compound was the 3,4‐dichloro, 7‐methyl derivative 17 which inhibited the Escherichia coli and Pneumocystis carinii thymidylate syntheses 50% at 5 × 105 M. Our results confirm the importance of the 7‐CH3 group and electron withdrawing groups on the aromatic side chain for thymidylate synthase inhibition.
A convenient preparation of 4,8‐dimethoxy‐3‐substituted‐2(1H)‐quinolones by an electrophilic reaction through base‐induced deprotonation and its synthetic application for the synthesis of new alkaloids, 3,4,8‐trimethoxy‐2(1H)‐quinolone and 3‐formyl‐4,7,8‐trimethoxy‐2(1H)‐quinolone(glycocitridine)
Authors: Tagawa Yoshinobu , Kawaoka Takamitsu , Goto Yoshinobu 
Published: April 2009

AbstractSome 4,8‐dimethoxy‐3‐substituted‐2(1H)‐quinolones were prepared by electrophilic reaction of 4,8‐dimethoxy‐2(1H)‐quinolone with electrophiles in the presence of n‐butyllithium‐N,N,N',N'‐tetramethylethyl‐enediamine in fairly good yields. This present method was successfully applied for the synthesis of two new alkaloids bearing the 4,8‐dimethoxy‐2(1H)‐quinolone skeleton.
Studies in anthraquinone: Preparation of 2‐substituted pyrimidoanthraquinones and related fused 1,2,4‐triazolo, tetrazolo and pyrazolino derivatives
Authors: Kangani C. O. , Master H. E. 
Published: April 2009

AbstractThis paper describes the synthesis of 2‐substituted‐4(3H)‐oxopyrimido[4,5‐a]anthraquinone, 2‐substi‐tuted‐4‐hydrazinopyrimido[4,5‐a]anthraquinones, several 2‐substituted‐1,2,4‐triazolo[4,3‐c]pyrimido[4,5‐a]‐anthraquinones tetrazolo[4,5‐c]pyrimido[4,5‐a]anthraquinones and pyrazolinopyrimidoanthraquinone derivatives.
Nitrosation of methyl 2‐cinnamoylamino‐3‐dimethylaminopropenoates. Alkyl N‐cinnamoyloxalic acid hydroxyimidic amides, intermediates in the synthesis of alkyl 5‐styryl‐1,2,4‐oxadiazole‐3‐carboxylates
Authors: Kmetič Matej , Stanovnik Branko 
Published: April 2009

AbstractAlkyl 2‐(substituted cinnamoylamino)‐3‐dimethylaminopropenoates 5, prepared either from glycine (1) and substituted cinnamoyl chlorides 2 via oxazol‐5(4H)‐ones 4, or from cinnamoylglycinate with t‐butoxy‐bisdimethylaminomethane, were transformed by nitrosation into 5‐substituted‐1,2,4‐oxadiazole‐3‐carboxylates 8. The formation of alkyl N‐cinnamoyloxalic acid hydroxyimidic amides 7, which were isolated as intermediates, represent a novel synthesis of N‐acyl substituted hydroxyimidic amides.
Synthesis of benzothiophene analogues of ketoconazole and itraconazole
Authors: Bolós Jordi , Gilbert Santiago , Anglada Lluis , Sacristan Aurelio , Ortiz José A. 
Published: April 2009

AbstractThe synthesis of the benzothiophene analogues of the orally active antifungal agents ketoconazole and itraconazole 3a and 3b is reported. The key heterocyclic system 3‐(1‐piperazinyl)benzo[b]thiophene is prepared by formation of the enamine between a benzothienone and ethyl 1‐piperazinecarboxylate. After elaboration of the respective N‐substituents, the methoxy group is cleaved with boron tribromide, and O‐alky‐1ated with the corresponding mesylates.
UV and MO study on the deprotonation of some 2‐aryl‐Δ2‐1,3,4‐oxadiazoline‐5‐thiones
Authors: Tsoleridis C. A. , Charistos D. A. , Vagenas G. V. 
Published: April 2009

AbstractSubstituent effects on the deprotonation processes of a series of 2‐aryl‐Δ2‐1,3,4‐oxadiazoline‐5‐thione (1) derivatives have been studied experimentally as well as theoretically. The acid dissociation constants pKa have been determined spectrophotometrically in ethanol‐water solutions (7.5‐92.5%) and vary between 3.76 and 5.80. Semiempirical molecular orbital (MO) calculations (AM1 and PM3) were used for the investigation of the existence of possible tautomeric thione and thiol forms of the studied compounds. Strong correlation between the pKa values and the deprotonation enthalpies were evaluated.
Oxidation of 1‐[(aryl)(phenylseleno)methyl]‐, 1‐[(aryl)(arylthio)‐(phenylseleno)methyl]‐, and l‐[(aryl)(diphenylseleno)methyl]benzotriazoles with m‐chloroperbenzoic acid
Authors: Kang Yoon Ho , Kim Kyongtae 
Published: April 2009

AbstractDuring the last decade, benzotriazole (1) has received much attention as an excellent synthetic auxiliary [1]. Recently Katritzky, et al. [2] studied the oxidation of 1‐(phenylthiomethyl)benzotriazole (2a) and 1‐(2‐phenyl‐1‐phenylthioethyl)benzotriazole (2b) and obtained their sulfones and sulfoxides by treatment with wj‐chloroperbenzoic acid (m‐CPBA) and sodium periodate, respectively. No compounds derived from a heterolytic cleavage between the α‐carbon and the N‐1 atoms of the foregoing compounds were isolated.
Synthesis of 2‐phenylimidazo[2,1‐b]benzothiazole derivatives as modulators of multidrug resistance for tumor cells
Authors: Tasaka Shigeyuki , Tanabe Hirokazu , Sasaki Yoshiyuki , Machida Toshiki , Iino Mayumi , Kiue Akira , Naito Seiji , Kuwano Michihiko 
Published: April 2009

AbstractWe have investigated 3‐substituted‐2‐phenylimidazo[2,1‐b]benzothiazole derivatives and herein we have discussed their pharmaceutical activities. We found that some 2‐phenyl‐5,6,7,8‐tetrahydroimidazo[2,1‐b]‐benzothiazoles could overcome multidrug resistance for tumor cells. Among them, 2‐phenyl‐3‐(N‐methyl‐3‐piperidyl)carbonylammomiinomemyl‐5,6,7,8‐tetrahydVoimidazo[2,1‐b]benzothiazole [N276‐12] demonstrated the most potent activity for overcoming multidrug resistance.
Pyridinium betaines derived from thiazolo and imidazoacridinones
Authors: Galy Jean‐Pierre , Hanoun Jean‐Pierre , Pique Valerie , Jagerovic Nadine , Elguero JosÉ 
Published: April 2009

AbstractFour betaines derived from imidazo[4,5‐a], imidazo[5,4‐a] and thiazolo[5,4‐a]acridine have been prepared in a six step procedure starting from 2‐chlorobenzimidazoles and benzothiazoles. The 1H and 13C nmr has been used to characterize the compounds, particularly the orientation of the step leading to the formation of the acridinone ring. The uv‐visible spectra of one betaine (wave numbers v in cm−1) shows a linear dependence with Reichardt's ET parameter and a high sensitivity to solvent effects.
An alternative synthesis of 10H‐indolo[3,2‐b]quinoline and its selective N‐alkylation
Authors: Fan Pingchen , Ablordeppey Seth Y. 
Published: April 2009

AbstractA new and a more efficient synthesis of 10H‐Indolo[3,2‐b]quinoline (quindoline) is reported. The synthesis involved N‐arylation of 3‐aminoquinoline with triphenylbismuth diacetate followed by oxidative cyclization using paOadium(II) acetate. A selective N‐alkylation methodology for quindoline was also developed. Alkylation on N‐5 was obtained in sulpholane, while alkylation on N‐10 was achieved in acetone in the presence of potassium hydroxide. A sequential N‐5‐ and N‐10 double alkylation procedure was also formulated.
Synthesis of pyrazolo‐fused heterocycles by a tandem appel's dehydration/electrocyclization methodology
Authors: Lee Kee‐Jung , Kwon Heung‐Taeck , Kim Boo‐Geun 
Published: April 2009

AbstractThe hydrazones of benzophenone, benzil, and acetophenone were allowed to react with acetoacetanilide to give azinoamides 18, and the reaction of 18 with Appel's dehydrathon contiditons (triphenylphosphine/carbon tetra‐chloride/triethylatnine) led to the corresponding azinoketimines 19, which underwent elctrocyclic ring closure under the reaction conditions to give pyrazolo‐fused heterocycles. Azinoamide 18a gave a 4,9‐dihydropyazolo‐[5,1‐b]quinazoine 21, while 18b yielded 2,3‐dihydro‐1H‐imidazo[1,2‐b]pyrazol‐2‐one 26 and 1H‐imidazo[1,2‐b]‐pyrazole 29. Compound 18c gave a monocyclic N‐α‐styryl‐5‐(phenylamino)pyrazole 32.
Diethyl ethoxymethylenemalonate in triheterocycles: A new synthesis of pyrido[3,2‐e]pyrimido[1,2‐c]pyrimidines
Authors: Dave Chaitanya G. , Shukla Manish C. 
Published: April 2009

AbstractDiethyl ethoxymethylenemalonate was used for the novel synthesis of the triheterocyclic 3‐carbethoxy‐9,ll‐disubstituted‐4‐oxo‐4H‐pyrido[3,2‐e]pyrimido[1,2‐c]pyrimidines from 4‐aminopyrido[2,3‐d]pyrim‐idines via thermal cyclization of the intermediate ethyl 2‐carbethoxy‐3‐[5,7‐disubstituted‐4‐amino‐pyrido[2,3‐d]pyrimidin‐4‐yl]acrylates. The alkaline hydrolysis of 3‐carbethoxy‐4‐oxo‐4H‐pyrido[3,2‐e]‐pyrimido[1,2‐c]pyrimidines was performed to give corresponding acid derivatives.
Reaction of 1,2‐diamines with 4‐hydroxycoumarin. Synthesis of 1,4‐diazepin‐5‐ones
Authors: Hamdi MaÂMar , Cottet Sophie , Tedeschi Christine , Spéziale Vincent 
Published: April 2009

Abstract1,4‐diazepin‐5‐ones were obtained from 4‐hydroxycoumarin and substituted 1,2‐diamines by heating in 2‐methyl‐1‐propanol.
An unusual substituent effect in a cycloaddition of an azolium ylide 1,3‐dipole: An inverted V‐shaped hammett plot
Authors: Butler Richard N. , Grogan Denise C. , Burke Luke A. 
Published: April 2009

AbstractAn unusual inverted V‐shaped Hammett plot has been observed for substituent effects at the N‐terminus of 1,2,3‐triazolium‐1‐imide 1,3‐dipoles in cycloaddition reactions. Theoretical studies (3‐21G and 6‐31G) suggest strong resonance interactions separately stabilizing both ends of the dipole.
The synthesis of novel polycyclic heterocyclic ring systems. 3. Synthesis and NMR spectroscopy of 15‐chloro[1]benzo‐thieno[2″,3″:3′,4′]naphtho[1′,2′:4,5]thieno[2,3‐c]quinoline
Authors: Sasaki Kenji , Tokuda Osamu , Hirota Takashi , Luo Jiann‐Kuan , Federspiel Ronald F. , Castle Raymond N. 
Published: April 2009

AbstractThe polycyclic heterocyclic compound with a novel ring system, 15‐chloro[1]benzothieno[2″,3″:3′,4′]‐naphtho[1′,2′:4,5]thieno[2,3‐c]quinoline was synthesized via photocyclization of 3‐chloro‐N‐phenyl[1]‐benzothieno[2′,3′:3,4]naphtho[2,1‐b]fhiophene‐2‐carboxamide followed by chlorination with phosphorus oxychloride. The assignment of its 1H and 13C nmr spectra was accomplished by utilizing two‐dimensional nmr methods.