bluuebunny/crossref_metadata_2025_split huggingface dataset:
13C‐15N Connectivity networks via unsymmetrical indirect covariance processing of 1H‐13C HSQC and 1H‐15N IMPEACH spectra
Authors: Martin Gary E. , Hilton Bruce D. , Irish Patrick A. , Blinov Kirill A. , Williams Antony J. 
Published: March 2009

Abstractmagnified imageLong‐range 1H‐15N heteronuclear shift correlation methods at natural abundance to facilitate the elucidation of small molecule structures have assumed a role of growing importance over the past decade. Recently, there has also been a high level of interest in the exploration of indirect covariance NMR methods. From two coherence transfer experiments, A→B and A→C, it is possible to indirectly determine B⟷C. We have shown that unsymmetrical indirect covariance methods can be employed to indirectly determine several types of hyphenated 2D NMR data from higher sensitivity experiments. Examples include the calculation of hyphenated 2D NMR spectra such as 2D GHSQC‐COSY and GHSQC‐NOESY from the discrete component 2D NMR experiments. We now wish to report the further extension of unsymmetrical indirect covariance NMR methods for the combination of 1H‐13C GHSQC and 1H‐15N longrange (GHMBC, IMPEACH‐MBC, CIGAR‐HMBC, etc.) heteronuclear chemical shift correlation spectra to establish 13C‐15N correlation pathways.
Synthesis of some new five membered heterocycles, a facile synthesis of oxazolidinones
Authors: Demirbas Ahmet , Ceylan Sule , Demirbas Neslihan 
Published: March 2009

Abstractmagnified imageThe synthesis and structural properties of two kinds of thiosemicarbazide derivatives (2a‐c and 3a‐c) and one kind of semicarbazide derivatives (4a, 4b) have been described. These compounds were synthesized by treating 2‐(4‐amino‐3‐alkyl‐5‐oxo‐4,5‐dihydro‐1H‐1,2,4‐triazol‐1‐yl)acetohydrazides (1a‐c) with benzyl isothiocyanate, 3‐florophenyl isothiocyanate and benzylisocyanate, respectively. The synthesis of 4‐amino‐3‐alkyl‐1‐[(4‐alkyl‐5‐mercapto(or 5‐oxo)‐4H‐1,2,4‐triazol‐3‐yl)methyl]‐4,5‐dihydro‐1H‐1,2,4‐triazol‐5‐ones (5a‐c, 6a‐c and 7) have been performed from the reaction with sodium hydroxide. On the other hand, the acidic treatment of compounds 2b, 3b and 4b has afforded 4‐amino‐3‐(4‐chlorobenzyl)‐1‐[(5‐alkylamino‐1,3,4‐thidazol(or 1,3,4‐oxazol)‐2‐yl)methyl]‐4,5‐dihydro‐1H‐1,2,4‐triazol‐5‐ones (8, 9 and 10). The condensation of thiosemi(or semi)carbazide derivatives (2a‐c, 3c and 4b) with 4‐chlorophenacylbromide have resulted in the formation of 2‐[4‐amino‐3‐alkyl‐5‐oxo‐4,5‐dihydro‐1H‐1,2,4‐triazol‐1‐yl]‐N′‐(3,4‐dialkyl‐1,3‐thiazol(or oxazol)‐2(3H)‐yliden]acetohydrazides (11a‐c, 12, 13), while their condensation with chloroacetic acid has produced 2‐[4‐amino‐3‐alkyl‐5‐oxo‐4,5‐dihydro‐1H‐1,2,4‐triazol‐1‐yl]‐N′‐[3‐(3‐alkyl)]‐4‐oxo‐1,3‐thiazolidin(or oxazolidin)‐2‐yliden}acetohydrazides (14, 15 and 16). The spectral data and elemental analyses have support the proposed structures.
Synthesis and reactions of some new allyl furobenzopyranone derivatives
Authors: El‐Desoky El‐Sayed I. 
Published: March 2009

Abstractmagnified imageReaction of visnaginone 1 with allyl bromide gave O‐allyl visnaginone 2 which underwent Claisen rearrangement to yield 7‐allylbenzofuran derivative 3. Reaction of 3 with different aromatic aldehydes gave the corresponding 5‐cinnamoylbenzofuran derivatives 4a‐d. Condensation of the latter chalcones 4a,c,d with hydrazine hydrate and phenylhydrazine provided, the corresponding pyrazoline derivatives 7a‐f. Claisen condensation of compound 3 with ethyl acetate and diethyl carbonate afforded Claisen adducts 8 and 12 which easily cyclized to 9 and 13, which are endowed with interesting biological properties.
Studies on the synthesis of the azocino[4,3‐b]indole framework and related compounds
Authors: Uludag Nesimi , Patir Suleyman 
Published: March 2009

Abstractmagnified imageAn efficient method for the synthesis of C‐4 position alkylated azocino[4,3‐b]indole 13 and 18 is described. Reduction of compounds 5, 6, 7 and 8 yielded the corresponding alcohols. Compounds 5, 6, 7 and 8 were synthesized through several steps starting from 1. The resulting alcohols underwent acid catalyzed ring closure to give tetracyclic azocino[4,3‐b]indole 9, 10, 11 and 12. Finally, compounds 9 and 17 were alkylated at C‐4 position to the corresponding products 13 and 18. The structure of the compounds 13 and 18 has been confirmed by X‐ray single crystal analysis.
Synthetic approaches towards the sulfonamide substituted‐4,5‐diaryl‐4H‐1,2,4‐triazole‐3‐thiones
Authors: Navidpour Latifeh , Amini Mohsen , Shafiee Abbas 
Published: March 2009

Abstractmagnified imageA new series of 3‐alkylthio‐4,5‐diaryl‐4H‐1,2,4‐triazoles having a SO2NH2substituent in thepara‐position on one of the aryl rings (19/25) were prepared starting from the appropriate benzoic acid hydrazides (15/21). Reaction of the corresponding hydrazides with the appropriate isothiocyanates yielded16/22, which were cyclized in basic media to give 4,5‐diaryl‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐thiones17/23. Alkylation of17/23afforded the alkylthio compounds18/24. Final debenzylation was achieved with concentrated sulfuric acid to give the target sulfonamides19/25.
Synthesis and characterization of some derivatives of lupinine and aminolupinine. Collision induced dissociation mass spectrometry studies of protonated molecules
Authors: Tlegenov Rust T. , Pakarinen Jaana M. H. , Oresmaa Larisa , Ahlgrén Markku , Vainiotalo Pirjo 
Published: March 2009

Abstractmagnified imageSome ester, amide and thioether derivatives of lupinine, aminolupinine and bromolupinine were synthesized and characterized in order to search biologically active compounds. The protonated molecules were studied by tandem mass spectrometry using collision induced dissociation (CID) technique in order to find out how different structural features and functional groups in different quinolizidine derivatives influence fragmentation behavior. Some theoretical calculations were also made to clarify the conformations of neutral and protonated molecules, to reveal the fragmentation routes and the product ions obtained. The functional groups clearly directed the fragmentations although the typical fragments for lupinine were still observed in all the cases. Theoretical calculations were in agreement with observed fragmentations and greatly helped interpretation of the CID spectra.
Synthesis of some novel 2,6‐disubstituted pyridazin‐3‐ones as TMC120 analogues
Authors: Loksha Yasser M. , Pedersen Erik B. , La Colla Paolo , Loddo Roberta 
Published: March 2009

Abstractmagnified imageDifferent analogues of TMC120 derived from pyridazin‐3(2H)‐one rings were synthesized by coupling of 3,6‐dichloropyridazine with arylacetonitriles, phenols and/or aniline derivative followed by hydrolysis and alkylation with different benzyl bromide derivatives.
A simple and efficient synthesis of novel N,N′‐bis (1H‐pyrrol‐1‐yl)‐1‐[2‐(2‐aryl‐5‐methyl‐3‐oxo‐2,4‐dihydro‐3H‐1,2,4‐triazol‐4‐yl)ethyl]‐1H‐1,2,3‐triazole‐4,5‐dicarboxamides
Authors: Latthe Prashant R. , Sunagar Vinay A. , Badami Bharati V. 
Published: March 2009

Abstractmagnified imageOne‐pot reaction of 3‐aryl‐5‐methyl‐1,3,4‐oxadiazolin‐2‐ones 1a‐g with ethanolamine yielded the 4‐(2‐hydroxyethyl)‐2‐aryl‐5‐methyl‐2,4‐dihydro‐3H‐1,2,4‐triazolin‐3‐ones 2a‐g which were converted to the azido compounds 6a‐g. These azides on 1,3‐dipolar cycloaddition with DMAD afforded the dimethyl‐1‐[2‐(2‐aryl‐5‐methyl‐3‐oxo‐1,2,4‐triazol‐4‐yl)ethyl]‐1H‐1,2,3‐triazol‐4,5‐dicarboxylates 7a‐g which on conversion to bishydrazides 8a‐g and further cyclisation with 2,5‐hexanedione afforded the title compounds 9a‐g. This new short route for the so far unkown bis‐(triazolinone‐triazole)ethanes involves mild and convergent 1,3‐dipolar cycloaddition reaction yielding overall good yields of the products.
Regioselective synthesis of 4‐aryloxymethylene‐2,3,5‐trihydrothiopyrano[3,2‐b]indoles by the thio‐claisen rearrangement of 3‐(4′‐aryloxybut‐2′‐ynylthio)indoles
Authors: Majumdar K. C. , Alam S. , Muhuri S. 
Published: March 2009

Abstractmagnified imageA number of new 4‐aryloxymethylene‐2,3,5‐trihydrothiopyrano[3,2‐b]indoles are regioselectively synthesized in 78‐84% yield by the thio‐Claisen rearrangement of 3‐(4′‐aryloxybut‐2′‐ynylthio)indoles. The endocyclic double bonded products are isolated by introducing electron withdrawing acetyl group at the indole nitrogen and also can be converted to the corresponding exocyclic isomers by deacetylation and subsequent heating.
Synthesis and anti‐staphylococcal activity of new halogenated pyrroles related to Pyrrolomycins F
Authors: Raimondi Maria Valeria , Schillaci Domenico , Petruso Salvatore 
Published: March 2009

Abstractmagnified imageThe chemical synthesis of new halogenated pyrroles related to pyrrolomycins F is described and the anti‐staphylococcal activity compared. The replacement of 4′‐bromo atom of parent compounds with two chloro atoms at 3′ and 5′ position increase the antibacterial activity against a reference strain of S. aureus.
Traceless synthesis of quinazoline‐2,4‐diones by curtius rearrangement reaction using poly(ethylene glycol) as soluble polymeric support
Authors: Huang Yanling , Lu Cuifen , Chen Zuxing , Yang Guichun 
Published: March 2009

Abstractmagnified imageWe have developed an efficient method to synthesize various quinazoline‐2,4‐diones using poly‐(ethylene glycol) as soluble polymeric support. The procedure of this reaction included: formation of acyl azide, efficient Curtius rearrangement, nucleophlic addition with amines to produce ureas, cyclization and concurrent cleavage of the resulted six‐membered heterocycle from PEG‐support in excellent yields. This method is mild and manipulation is easy.
Synthesis and nicotinic acetylcholine receptor affinity of bivalent tropane‐3‐carboxylates
Authors: Zhang Suhong , Cheng Jie , Liu Ying , Xu Liang , Trudell Mark L. , Izenwasser Sari , Wade Dean 
Published: March 2009

Abstractmagnified imageA series of diol di‐(tropane‐3α‐carboxylate) esters and diol di‐(tropane‐3β‐carboxylate) esters were synthesized from 3‐tropene‐3‐carboxylic acid and tropane‐3β‐carboxylic acid, respectively. The bivalent tropane‐3‐carboxylates were evaluated for their ability to inhibit [3H]cytisine binding at rat brain nicotinic acetylcholine receptors (nAChRs). In general the (3β,3β')‐isomers were more potent than (3α,3α')‐isomer and the (3β,3β')‐decyl derivative (n = 10, Ki = 145 nM) exhibited the most potent affinity for nAChRs of the series.
A novel synthesis of (±)‐harmacine and (±)1,2,3,4,6,7,12,12b‐octahydroindole[2,3‐a]quinolizine
Authors: King Frank D. 
Published: March 2009

Abstractmagnified imageA three‐step synthesis of (±)‐harmacine is described from the readily available 4,4‐diethoxybutan‐1‐amine via an acid‐mediated acyl iminium ion cyclisation. The synthesis of the homologous (±)1,2,3,4,6,7,12,12b‐octahydroindole[2,3‐a]quinolizine from 5,5‐diethoxypentan‐1‐amine is also described. Although similar, the two systems required very different cyclisation conditions.
An efficient and facile procedure for the synthesis of 4,6‐diaryl‐2(1H)‐pyridones under solvent‐free conditions
Authors: Rong Liangce , Wang Haiying , Shi Jingwen , Yang Fang , Yao Hao , Tu Shuajiang , Shi Daqing 
Published: March 2009

Abstractmagnified imageAn efficient and convenient method for the preparation of 4,6‐diaryl‐2(1H)‐pyridones by the one‐pot reaction of aromatic aldehydes, aromatic ketones and malononitrile, in the presence of sodium hydroxide under solventfree condition is reported. This method has the advantages of good yields, mild reaction conditions, easy workup, inexpensive reagents and being environmentally friendly over the existing procedures.
Synthesis of furanyl and oxazolyl N‐substituted piperidine and imidazoline salts as potential agonists of M1 muscarinic receptors
Authors: Aguado Andreina , Boulos John , Carreras Anladys , Montoya Angelica , Rodriquez Judith 
Published: March 2009

Abstractmagnified imageFuranyl and oxazolyl N‐substituted imidazoline salts were prepared by reacting furanyl and oxazolyl esters with ethylenediamine and trimethyl aluminum, followed by the addition of methyl iodide or hydrogen chloride. The piperidinium salts were prepared by treating furanyl and oxazolyl chlorides with piperidine base, followed by the addition of methyl iodide or hydrogen chloride.
Synthesis of highly functionalized 2‐(substituted biphenyl) benzimidzoles via suzuki‐miyaura cross coupling reaction
Authors: Vinodkumar Ramanatham , Rajagopal Kotarkonda , Devanna Nayakanti 
Published: March 2009

Abstractmagnified imageA facile and convenient method for the synthesis of highly functionalized 2‐(substitutedbiphenyl) based benzimidazoles has been reported by the application of Suzuki‐Miyaura cross coupling reaction.
Palladium/tetraphosphine catalyzed suzuki cross‐coupling of heteroarylboronic acids with aryl halides
Authors: Kondolff Isabelle , Doucet Henri , Santelli Maurice 
Published: March 2009

Abstractmagnified imagecis,cis,cis‐1,2,3,4‐Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C3H5)]2 efficiently catalyses the Suzuki reaction of heteroarylboronic acids with aryl bromides and also the coupling of arylboronic acids with heteroaryl bromides. The coupling of thiophene‐ or benzothiopheneboronic acids, furan‐ or benzofuranboronic acids and 3‐pyridineboronic acid with a variety of aryl bromides gave the corresponding coupling products in good yields. However, in most cases, better results in terms of ratio substrate/catalyst were obtained for the reverse reaction using heteroaryl bromides with arylboronic acids.
Fused polyaza‐heterocycles and 1,3,4‐thiadiazoles via a tricyano synthon
Authors: Dawood Kamal M. , Raslan Mohamed A. 
Published: March 2009

Abstractmagnified imageTreatment of 2‐cyano‐3‐phenyl‐2‐pentenedinitrile with some heterocyclic diazonium salts afforded the corresponding heterocyclic hydrazones. Some of the latter hydrazones were converted into fused polyaza‐heterocycles upon boiling in pyridine. Reaction of 2‐cyano‐3‐phenyl‐2‐pentenedinitrile with phenylisothiocyanate gave a tricyano‐thiole derivative which on treatment with hydrazonoyl chlorides and 1‐(benzothiazol‐2‐yl)‐2‐bromoethanone furnished 1,3,4‐thiadiazole and thiazole derivatives, respectively.
Fluorescent 6‐hydroxy‐ and 6,7‐dihydroxy‐4‐trifluoro‐methylcarbostyrils and formation of o‐carboxymethylated derivatives via o‐succinimide esters
Authors: Uray Georg , Badgujar Naresh S. , Kováčková Sona , Stadlbauer Wolfgang 
Published: March 2009

Abstractmagnified imageStepwise demethylation of fluorescent 6,7‐dimethoxy‐3‐trifluoromethylcarbostyrils 5 leads to 6‐hydroxy derivatives 6 and 6,7‐dihydroxyderivative 7. Phenolate formation shifts excitation and emission maxima from 370 and 430 nm to 430 and 480 nm for the anion of 6 and as far as 500 and 580 nm for the dianion of 7. Dependence of fluorescence quantum yield on media and polar structure, varying from 0.02 to 0.51, is discussed. O‐Alkylation of 6 with alkyl bromoacetate yields esters of type 8 in good yield. Reactive succinimidoyl (OSu) esters of type 11 were prepared after saponification to acids 9. With amino acids or their esters, peptides and aminoglucose, linking to labeled derivatives 13 or 15 could be achieved under mild conditions in slightly basic aqueous media.
1,3‐Dipolar cycloadditions of (4R*,5R*)‐1‐alkylidene‐4‐(benzoylamino)‐5‐phenyl‐3‐pyrazolidinon‐1‐azomethine imines
Authors: Pezdirc Lidija , Grošelj Uroš , Meden Anton , Stanovnik Branko , Svete Jurij 
Published: March 2009

Abstractmagnified image1,3‐Dipolar cycloadditions of azomethine imines 3a and 3b, available by acid‐catalyzed treatment of 3‐pyrazolidinone 1 with acetone (2a) and butyraldehyde (2b), respectively, were studied. Reactions of 3a with DMAD (4) afforded a mixture of products 9 and 10a, whilst treatment of 3b with DMAD (4) gave a mixture of compound 9 and epimeric cycloadducts 10/10′b. On the other hand, cycloadducts 13a,b‐16a,b were isolated as single diastereomers in 9–37% yields upon reactions of 3a,b with olefinic dipolarophiles 5–8. The structures of cycloadducts 9, 10a, 10/10′b, and 13a,b‐16a,b were determined by 1H nmr and NOESY spectroscopy. The structure of compound 13a was confirmed by X‐ray diffraction.
Preparation of 2‐(1H‐pyrazol‐5‐yl)benzenesulfonamides from polylithiated C(α),N‐carbo‐tert‐butoxyhydrazones and methyl 2‐(aminosulfonyl)benzoate
Authors: Knight John D. , Brown Jordan B. , Overby Jason S. , Beam Charles F. , Dwight Camper N. 
Published: March 2009

Abstractmagnified imageSelect C(α), N‐carbo‐tert‐butoxyhydrazones were dilithiated with excess lithium diisopropylamide followed by condensation with methyl 2‐(aminosulfonyl)benzoate, acid cyclization, hydrolysis, and decarboxylation to afford new 2‐(1H‐pyrazol‐5‐yl)benzenesulfonamides, [NH‐pyrazolyl‐ortho‐benzene‐sulfonamides].
Application of the acetate of baylis‐hillman adducts in the synthesis of 3‐carbomethoxy‐2H‐thiochromenes
Authors: Cha Myeong Jong , Song Young Seok , Han Eun‐Gu , Lee Kee‐Jung 
Published: March 2009

Abstractmagnified imageA new route to 2H‐thiochromenes using the tandem SN2′ and SNAr reaction of several Baylis‐Hillman acetates having an ortho‐substituent, such as a halogen or nitro group, with sodium sulfide in aqueous dimethyl sulfoxide has been described.
Preparation of novel azabicyclic amines and α7 nicotinic acetylcholine receptor activity of derived aryl amides
Authors: Walker Daniel P. , Acker Brad A. , Jon Jacobsen E. , Wishka Donn G. 
Published: March 2009

Abstractmagnified imageThree new azabicyclic amines, namely exo‐3‐amino‐1‐azabicyclo[3.2.1]octane, 3‐amino‐1‐azabicyclo‐[3.2.2]nonane and exo‐6‐amino‐8‐azabicyclo[3.2.1]octane, have been designed and prepared as isosteres of 3‐aminoquinuclidine. Aryl amides derived from each series were prepared and tested in an α7 nicotinic acetylcholine receptor assay as part of a drug discovery program to treat the cognitive deficits in schizophrenia. All new amides showed significant α7 nAChR activity and one series displayed potent α7 activity equal to the quinuclidine series.
Regioselective synthesis of diazaspiro[4.4]nona‐ and tetrazaspiro[4.5]deca‐2,9‐diene‐6‐one derivatives
Authors: Farag Ahmad M. , Elkholy Yehya M. , Ali Korany A. 
Published: March 2009

Abstractmagnified imageSeveral 1,2‐diazaspiro[4,4]nona‐2,8‐diene‐6‐one derivatives were synthesised via cycloaddition of nitrilimides to 3‐aryliden‐2(3H)‐furanone derivatives. The formed products react with hydrazine hydrate to give the corresponding pyrazolecarbohydrazide derivatives which undergo intramolecure cyclization upon treatment with HCl/AcOH mixture to affored 1,2,7,8‐tetrazaspiro[4.5]deca‐2,9‐diene‐6‐one derivatives. Molecular mechanics energy minimization techniques and related structural parameters for compound 8‐(4‐methylphenyl)‐1,3,4‐triphenyl‐7‐oxa‐1,2‐diazaspiro[4.4]nona‐2,8‐diene‐6‐one 5a are reported.
Stereoselective synthesis of helical dihydrodipyrrolophenanthroline and hindrance hexa tert‐butyl carboxylatodipyrrolophenanthroline from reaction between 1,10‐phenanthroline and dialkyl acetylenedicarboxylates
Authors: Maghsoodlou Malek Taher , Khorassani Sayyed Mostafa Habibi , Saghatforoush Lotfali , Maghfuri Farhad , Marandi Ghasem , Kabiri Roya 
Published: March 2009

Abstractmagnified imageHigh hindrance Hexa tert‐butoxy carbonyl dipyrrolophenanthroline and helical dihydropyrrolophen‐anthroline compounds were prepared from reactions between di tert‐butyl acetylenedicarboxylate and 1,10‐phenanthroline in polar solvents media.
Synthesis of new di‐ and tetraazadibenzosulfoxide macrocycolic compounds
Authors: Shockravi Abbas , Yousefi Ali , Tabrizi Samad Bavili , Zakeri Masoomeh , Abouzari‐Lotf Ebrahim , Sharghi Hashem 
Published: March 2009

Abstractmagnified imageNovel macrocyclic di and tetraamide compounds have been synthesized by the reaction of 2‐2′‐sulfoxide‐bis‐(4‐methyl phenoxy) aceticester or aceticacid chloride) (obtained from corresponding bisphenol) with appropriate diamines. Also the results of the presence of base as template are discussed and compared.
1,3‐Dipolar cycloaddition of stabilized azomethine ylides to alkenyl quinolines: An efficient route to polyfunctionalized 3‐pyrrolidinylquinoline derivatives
Authors: Bouraiou Abdelmalek , Debache Abdelmadjid , Rhouati Salah , Belfaitah Ali , Carboni Bertrand 
Published: March 2009

Abstractmagnified imageSome new polysubstituted 3‐pyrrolidinylquinolinyl derivatives were prepared by 1,3 dipolar cycloadditions of an azomethine ylide, generated in situ from benzylideneimine of methylglycinate and triethylamine in the presence of LiBr, to quinolyl α,β‐unsaturated esters
Synthesis and characterization of new trifluoromethyl substituted 3‐ethoxycarbonyl‐ and 3‐pyrimidin‐2‐yl)‐(1,2,3)‐oxathiazinane‐S‐oxides
Authors: Zanatta Nilo , Borchhardt Deise M. , Flores Darlene C. , Coelho Helena S. , Marchi Tiago M. , Flores Alex F. C. , Bonacorso Helio G. , Martins Marcos A. P. 
Published: March 2009

Abstractmagnified imageThis paper describes the synthesis and characterization of a new series of 4‐substituted‐3‐ethoxycarbonyl‐6‐trifluoromethyl‐(1,2,3)‐oxathiazinane‐S‐oxides and 3‐(4,6‐diphenyl‐pyrimidin‐2‐yl)‐6‐trifluoromethyl‐(1,2,3)oxathiazinane‐S‐oxides from the cyclization reaction of 4,4,4‐trifluoro‐3‐hydroxybutylcarbamates and 4‐(4,6‐diphenyl‐pyrimidin‐2‐ylamino)‐1,1,1‐trifluoro‐butan‐2‐ols with thionyl chloride. The analysis of the NMR data allowed us to define important features of the molecular structure. Significant chemical and structural differences were observed between the trifluoromethylated oxathiazinanes obtained in this work from other analogue compounds reported in the literature.
Simple and efficient one‐pot synthesis of 3,4‐dihydro‐2‐pyridones via solid‐supported Bi(III)nitrate catalyzed double michael addition‐azaannulation
Authors: Singh Jagjeet , Koul Summon , Sharma Rattan L. , Razdan Tej K. , Pannu Ajay P. S. 
Published: March 2009

Abstractmagnified image4‐Aryl‐5‐carboethoxy‐6‐methyl‐2,3‐dihydro‐2‐pyridones were obtained, in high yield, by heating ternary mixtures of appropriate aldehydes, ethylacetoacetate and compounds possessing NH2‐C=X functionality, in presence of immobilized Bi(III)nitrate and co‐catalyst Zn(II)chloride, under solventless conditions. The reaction proceeds smoothly at 140±5°C and seems to involve double Michael addition‐azaannulation.
Synthesis of 3‐arylazo‐6‐oxopyridazin‐5‐carbonitriles: A versatile precursor for condensed arylazopyridazin‐6‐ones
Authors: Al‐Mousawi Saleh M. , El‐Apasery Morsy A. , Al‐Kandery Najat , Elnagdi Mohamed H. 
Published: March 2009

Abstractmagnified image1‐[2‐Phenyl‐1‐diazenyl]‐1‐[2‐phenylhydrazono]acetone or 1‐[‐2‐(4‐methylphenyl)‐1‐diazenyl]‐1‐[‐2‐(4‐methylphenyl)hydrazono]‐butan‐2‐one were produced via coupling the (E) 2‐oxopropanal‐1‐phenyl‐hydrazone or (E) 2‐oxobutanal‐1‐(4‐methylphenyl)hydrazone with aromatic diazonium salts. These formazanes condensed readily with ethyl cyanoacetate to yield 5‐methyl‐3‐oxo‐2‐phenyl‐6‐phenylazo‐2,3‐dihydropyridazine‐4‐carbonitrile compound (9a), 5‐ethyl‐3‐oxo‐2‐p‐tolyl‐6‐p‐tolylazo‐2,3‐dihydro‐pyridazine‐4‐carbonitrile and/or 5‐ethyl‐3‐oxo‐2,6‐di‐p‐tolyl‐2,3‐dihydropyridazine‐4‐carbonitrile that reacted with sulphur in presence of piperidine to yield the aminothienopyridazinones. The latter reacted with electron poor olefins and acetylenes to yield aminophthalazines. Compound (9a) reacted also with benzylidenemalononitrile to yield the arylazophthalazinone.
Synthesis and characterization of a novel heterocycle: 1‐Substituted‐4‐arylazamethylene‐6‐arylpyrazolo[5,4‐d]‐1,3‐oxazine
Authors: He Kunlun , Qiu Guofu , Hu Xianming , Lv Houjun , Wang Junbo 
Published: March 2009

Abstractmagnified imageA series of novel heterocycles 1‐aryl‐ or alkyl‐substituted‐4‐arylazamethylene‐6‐arylpyrazolo[5,4‐d]‐1,3‐oxazines were synthesized from the acylation of (5‐amino‐1‐substituted‐pyrazol‐4‐yl)‐N‐carboxamide in 63‐89% isolated yields at room temperature within 12 hours. The structure was confirmed by X‐ray crystal analysis.