bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of new derivatives of thieno[2,3‐b]pyridine fused with octyl ring
Authors: Al‐Omran Fatima A. , El‐Khair Adel A. 
Published: March 2009

Abstractmagnified imageDerivatives of thiophene, thieno[2,3‐b]pyridine, thieno[5′,4′:4,5]pyrimido[3,2‐a]pyridine and thiepine fused with octyl ring have been synthesized and tested for antimicrobial and antifungal activities. The structure of the newly synthesized compounds have been established on the basis of their analytical and spectral data.
Synthesis and characterization of 1,3,4‐oxadiazole‐triazolopyridinone hybrid derivatives as new blue‐greenish photoluminescent materials
Authors: Chiang Kuo‐Chen , Wong Fung Fuh , Chang Chih‐Shiang , Hour Mann‐Jen , Wang Yu‐Ling , Wen Shaw‐Bing , Yeh Mou‐Yung 
Published: March 2009

Abstractmagnified imageRecently, New functionalized oxadiazole‐triazolopyridinone hybrid compounds were investigated as photoluminescent materials. In this work, we introduce triazolopyridinone to synthesize a series of oxadiazole‐triazolopyridinone hybrid derivatives as potential photoluminescent materials and explore the effect of modification of the triazolopyridinone moiety. The λmax values of the photoluminescence (PL) spectra of 1,3,4‐oxadiazole‐triazolopyridinone hybrids are promoted to longer wavelengths (470‐486 nm) than the traditional 1,2,3‐triazole derivatives (410‐425 nm) in solutions. PL spectra 5a, 5d, and 5g of the vacuum evaporated films on quartz substrates, with a maximum at 487 nm, shows a red‐shift (∼15‐20 nm), with respect to the solution spectrum. The solution fluorescence quantum yields (Φf) were measured, all of which fell into the range 0.65‐0.76, and were determined relative to that of 2‐phenyl‐5‐(4‐biphenyl)‐1,3,4‐oxadiazole in benzene (Φf = 0.80). 1,3,4‐Oxadiazole‐triazolopyridinone hybrid derivatives show clearly non‐reversible reduction processes in cyclic voltammogram measurements. Following spectroscopic studies and observation of the electrochemical behaviors, 1,3,4‐oxadiazole‐triazolopyridinone derivatives were determined to be potential efficient bluegreenish photoluminescent materials.
Studies with enamines: Reactivity of N,N‐dimethyl‐N‐[(E)‐2‐(4‐nitrophenyl)‐1‐ethenyl]amine towards nitrilimine and aromatic diazonium salts
Authors: Al‐Matar Hamad M. , Riyadh Sayed M. , Elnagdi Mohamed H. 
Published: March 2009

Abstractmagnified imageIn the presence of triethylamine, cycloaddition reaction of enamine 1 with hydrazonoyl halides 2 followed by dimethylamine elimination was achieved, yielding the corresponding 1,3,4‐trisubstituted pyrazoles 4. Coupling of enamine 1 with aromatic diazonium salts afforded 2‐(arylhydrazono)‐2‐(4‐nitrophenyl)acetaldehyde 9 in good yield. Refluxing the phenyl hydrazone 9a with chloroacetone in ethanol in the presence of triethylamine afforded 1,3,5‐trisubstituted pyrazole 12a, formed via intermediate 11a. Reaction of 9a with hydroxylamine hydrochloride in ethanol in the presence of anhydrous sodium acetate yielded oxime 13a which was irradiated in a microwave oven in the presence of acetic acid to afford a mixture of 15a and 16a.
Preparation of spiro[benzoisothiazole‐isoxazole] dioxides from dilithiated c(α),O‐oximes and methyl 2‐(aminosulfonyl)benzoate
Authors: Grant Bonnie J. , Kramp Catherine R. , Knight John D. , Meierhoefer Michelle A. , Vella Jarrett H. , Sober Carolyn L. , Jones Stephen S. , Metz Clyde R. , Beam Charles F. , Pennington William T. , Vanderveer Donald G. , Dwight Camper N. 
Published: March 2009

Abstractmagnified imageSeveral dilithiated C(α), O‐oximes were prepared in excess lithium diisopropylamide‐tetramethyl‐ethylenediamine (LDA/TMEDA) and condensed with methyl 2‐(aminosulfonyl)benzoate followed by acid cyclization of intermediates to spiro(benzoisothiazole‐isoxazole) dioxides, a new spiro and fused‐ring system. Distortionless enhancement by polarization transfer (DEPT) and liquid chromatography mass spectrometry (LCMS) for all products, as well as X‐ray single crystal analysis on a representative product, were especially relevant for structure confirmation in this synthesis.
Novel azaandrostane derivatives for the synthesis of 17β‐(N‐tert‐butyl carbamoyl)‐4‐aza‐5α‐androst‐1‐ene‐3‐one
Authors: Srinivasa Rao Divvela V. N. , Trinadhachari Ganala Naga , Prabahar Koilpillai Joseph , Dandala Ramesh , Sivakumaran Meenakshisundaram , Naidu Andra 
Published: March 2009

Abstractmagnified imageA new industrially viable process for the preparation of 1β‐(N‐tert‐butyl carbamoyl)‐4‐aza‐5α‐androst‐1‐ene‐3‐one, also known by the generic name finasteride (6) from the new azaandrostane derivatives such as 1β‐(N‐tert‐butyl carbamoyl)‐4‐benzoyl‐4‐aza‐5α‐androstane‐3‐one (4), 1β‐(N‐tert‐butyl carbamoyl)‐4‐benzoyl‐4‐aza‐5α‐androst‐1‐ene‐3‐one (5) is reported. In this process, benzoyl group is demonstrated as a novel protecting group for lactamic NH group. The structures of newly prepared compounds were established on the basis of spectral data (IR, 1H‐NMR, and MS).
Synthesis of alkyl 6‐methyl‐4‐(2‐trifluoromethylphenyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates possessing a N‐3 nitro substituent to determine calcium channel modulation structure‐activity relationships
Authors: Kaur Kuljeet , Knaus Edward E. 
Published: March 2009

Abstractmagnified imageThe Bigenelli acid catalyzed condensation of 2‐trifluoromethylbenzaldehyde (1), urea (2) and an alkyl acetoacetate (3) afforded the respective alkyl (Me, Et, i‐Pr, i‐Bu) 6‐methyl‐4‐(2‐trifluoromethylphenyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylate (4‐7). Subsequent N3‐nitration of the alkyl esters (4‐7) using Cu(NO3)2 3H2O and Ac2O furnished the target alkyl 6‐methyl‐3‐nitro‐4‐(2‐trifluoromethylphenyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates (8‐11). The N3‐nitro compounds (8‐11) were less potent calcium channel antagonists (IC50 values in the 1.9 × 10−7 to 3.9 × 10−6 M range) on guinea pig ileal longitudinal smooth muscle than the reference drug nifedipine (Adalat®, IC50 = 1.4 × 10−8 M). In vitro calcium channel modulation studies on guinea pig left atrium (GPLA) showed that the methyl and ethyl esters (8‐9) induced a weak‐to‐modest positive inotropic (agonist) effect, and that the inactive isopropyl (10) and isobutyl (11) esters did not alter the cardiac contractile force of GPLA.
Synthesis of thiazolo[3,2‐d][1,2,4] triazines through palladium‐catalyzed heteroannulation of acetylenic compounds
Authors: Heravia Majid M. , Kivanloo Ali , Rahimizadeh Mohammad , Bakavoli Mehdi , Ghassemzadeh Mitra 
Published: March 2009

Abstractmagnified imageThe reaction of 6‐methyl‐5‐(prop‐2‐ynylthio)‐5,6‐dihydro‐1,2,4‐triazin‐3(4H)‐one 1 with various iodobenzenes 2 in the presence of palladium catalyst leads to the formation of substituted triazolotriazines.
Synthesis of new spiro‐[isothiochromene‐3,5′‐isoxazolidin]‐4(1H)‐ones
Authors: Bennani Brahim , Baba Bouchra Filali , Larbi Najib Ben , Boukir Abdelatif , Kerbal Abdelali , Mimouni Mostafa , Hadda Taibi Ben , Trzaskowski Bartosz , Jalbout Abraham F. 
Published: March 2009

Abstractmagnified imageA series of seven new 2′,3′,4′‐substituted spiro[isothiochromene‐3,5′‐isoxazolidin]‐4(1H)‐ones (7‐13) has been prepared in the reaction of benzylidene(phenyl)azane oxide (5) or benzylidene(methyl)azane oxide (6) with (3Z)‐3‐(4‐substituted‐benzylidene)‐1H‐isothio‐ chromen‐4(3H)‐one (1‐4). The reaction occurs by a 1,3‐dipolar cycloaddition mechanism that leads to the regiospecific formation of various spiroisoxazolidines (7‐13).
The reaction of 3,4‐diamino‐1,2,5‐oxadiazoles with formaldehyde
Authors: Kakanejadifard A. , Saniei A. , Delfani F. , Farnia M. , Najafi G. R. 
Published: March 2009

Abstractmagnified imageThe compounds 5,6‐dihydro‐4H‐imidazo[4,5‐c][1,2,5]oxadiazole (3a, RH), 4,6,10,12‐tetramethyl‐5,6,11,12‐tetrahydro‐4H,10H‐bis(1,2,5)oxadiazolo[3,4‐d:3′,4′‐I][1,3,6,8]tetraazecine (4b, RCH3), N3,N3′‐methylenebis‐3,4‐diamino‐1,2,5‐oxadiazole (5a, RH) and N3,N3′‐methylenebis(N,N′‐dimethyl‐3,4‐diamino‐1,2,5‐oxadiazolee) (5b, RCH3) were synthesized from the reaction of formaldehyde with 3,4‐diamino‐1,2,5‐oxadiazole and N,N′‐3,4‐dimethylamino‐1,2,5‐oxadiazole in an acetonitrile.
Cycloaddition reactions of phthalimide substituted cyclic polyenes with heteroatom dienophiles
Authors: Templin Stephen S. , Wallock Nathaniel J. , Haworth Daniel T. , Donaldson William A. , Bennett Dennis W. , Siddiquee Tasneem 
Published: March 2009

Abstractmagnified imageThe cycloaddition of 6‐phthalimidobicyclo[5.1.0]octa‐2,4‐diene and 7‐phthalimido‐1,3,5‐cycloheptatriene with nitrosobenzene and with 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione each gave a single heterocyclic product. X‐ray crystallographic analysis of 8a indicated the regio‐ and stereoselectivity of this cycloaddition.
Synthesis of some pyrazolopyrimidines as purine analogues
Authors: Ahmed Sayed A. , Hussein Ahmed M. , Hozayen Walaa G. M. , El‐Ghandour Ahmed H. H. , Abdelhamid Abdou O. 
Published: March 2009

Abstractmagnified imagePyrazolo[1,5‐a]pyrimidines were synthesized from the appropriate 3‐aminopyrazoles with the appropriate sodium (3‐oxocycloalkylidene)methenolate, β‐diketone, β‐keto esters or 1,2‐disubstituted acrylonitrile. Elemental analyses, spectral data, alternative synthesis route and X‐ray elucidated structures of the newly synthesized compounds.
A new synthetic route to the synthesis of nordasycarpidone derivatives
Authors: Akdag Resmiye , Ergun Yavuz 
Published: March 2009

AbstractA new synthetic route for the synthesis of the nordasycarpidone derivative 11 which has hexahydro‐1,5‐methanoazocino[4,3‐b]indol skeleton, is described. Construction of the tetracyclic structure was achieved by catalytic reduction and cyclization reaction of the nitrile derivative. Also many new tetrahydrocarbazole derivatives (4, 5, 6, 7, 8, 9) and a dasycarpidol derivative (10) were synthesized.
Synthesis of new heterocycles containing more than one 1,2,3‐thia or selenadiazole rings
Authors: Al‐Smadi Mousa 
Published: March 2009

Abstractmagnified imageThe diketones 2a‐d with different alkyl chain length are used for the synthesis of di‐1,2,3‐thia or selenadiazole derivatives 4a‐d and 5a‐d. The diketones 2a‐d where prepared by a unique method through the reaction between the corresponding dibromoalkanes 1a‐d and ethyl acetoacetate, which are transformed into the corresponding semicarbazone derivatives 3a‐d. The di‐1,2,3‐thia or selenadiazole derivatives 4a‐d and 5a‐d were prepared from the semicarbazones derivatives 3a‐d on oxidative cyclization with thionyl chloride and selenium dioxide respectively in high yield.
Design and synthesis of diheterocyclic compounds containing tetrazolinone and 1,2,4‐triazole
Authors: Luo Yan‐Ping , Lin Long , Yang Guang‐Fu 
Published: March 2009

Abstractmagnified imageA novel series of 1‐(4‐chlorophenyl)‐4‐{[5‐(alkylthio)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl]methyl}‐1,4‐dihydro‐5H‐tetrazol‐5‐ones 6a‐y were synthesized in good to excellent yields and their structures were identified by 1H nmr, 13C nmr, ms and elemental analysis. Determining the X‐ray crystallography of compound 6j indicated that there were strong intermolecular hydrogen bonds in the stacking interactions. The bioassay results showed that compound 6k exhibited good insecticidal activities against T cinnabarinus at the dosage of 250 mg.L−1. To our knowledge, this is the first report about the insecticidal activity of tetrazolinone derivatives.
Synthesis and herbicidal activity of 2‐(3‐(trifluoromethyl)‐5‐(alkoxy)‐1H‐pyrazol‐1‐yl)‐4‐aryloxypyrimidine derivatives
Authors: Liu Wei‐Min , Zhu You‐Quan , Wang Yi‐Feng , Liu Bin , Zou Xiao‐Mao , Yang Hua‐Zheng 
Published: March 2009

Abstractmagnified imageA series of 2‐(3‐(trifluoromethyl)‐5‐(alkoxy)‐1H‐pyrazol‐1‐yl)‐4‐aryloxypyrimidine derivatives were designed and synthesized. The structures of all the title compounds were confirmed by 1H NMR and elementary analysis. These compounds were screened for herbicidal activity against rape and barnyard grass. Compound B13 exhibited moderate herbicidal activity.
Copper nitrate trihydrate catalyzed efficient synthesis of bis(indolyl)methanes in acetonitrile at room temperature
Authors: Nasreen Aayesha , Varala Ravi , Adapa Srinivas R. 
Published: March 2009

AbstractA catalytic amount of easily available and inexpensive Cu(NO3)3.3H2O (10 mol%) enables electrophilic substitution reaction of indole with structurally divergent aldehydes in acetonitrile to afford the corresponding bis(indolyl)methanes in moderate to excellent yields (65‐98%) at ambient temperature. The reaction is highly chemoselective and applicable only to aldehydes and not to ketones.
An efficient synthesis of new class of pyrazolo[3,4‐b]pyridine‐6‐one derivatives by a novel cascade reaction
Authors: Shi Feng , Zhang Junyong , Tu Shujiang , Jia Runhong , Zhang Yan , Jiang Bo , Jiang Hong 
Published: March 2009

Abstractmagnified imageA novel cascade reaction of 4‐arylidene‐2‐phenyl‐1,3‐oxazol‐5(4H)‐one with 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐amine was described and a number of new pyrazolo[3,4‐b]pyridine‐6‐one derivatives were synthesized. This new protocol has the advantages of shorter time, higher yields, and lower cost as well as easier operation.
(±)‐2‐alkyl‐1,2,3,4‐tetrahydroquinoline‐3‐carboxylic esters by a catalyst and pressure dependent tandem reduction‐reductive amination reaction
Authors: Bunce Richard A. , Nago Takahiro , Sonobe Nathan 
Published: March 2009

Abstractmagnified imageA series of 2‐(2‐nitrobenzyl)‐substituted β‐keto ester derivatives has been subjected to reductive cyclization under catalytic hydrogenation conditions. The reactions were found to be highly dependent on the catalyst and hydrogen pressure used. Hydrogenation over 5% palladium‐on‐carbon at 4 atmospheres pressure produced complex mixtures of products that included predominantly 1,2,3,4‐tetrahydroquinoline and quinoline products; at 1 atmosphere pressure, the same reactions gave mixtures containing predominantly tetrahydroquinoline and 1,4‐dihydroquinoline derivatives. Hydrogenation using 5% platinum‐on‐carbon was much cleaner and afforded the desired cis‐ and trans‐(±)‐2‐alkyl‐1,2,3,4‐tetrahydroquinoline‐3‐carboxylic esters, with the cis product predominating by ≥ 13:1.
Synthesis and some reactions of 4‐(ethoxycarbonyl)‐1,5‐diphenyl‐1H‐pyrazole‐3‐carboxylic acid
Authors: Şener Ahmet , Bildirici İshak , Tozlu İsrafil , Genç Hasan , Arısoy Kadir 
Published: March 2009

Abstractmagnified image1,5‐Diphenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid‐4‐ethyl ester 2, obtained from the 4‐ethoxycarbonyl‐5‐phenyl‐2,3‐furandione 1 and N‐benzylidene‐N′‐phenyl hydrazine, was converted via reactions of its acid chloride 3 with various alcohols or N‐nucleophiles into the corresponding ester 5 or amide derivatives 6, respectively. In addition, 2 was decarboxylated to give ethyl 1,5‐diphenylpyrazole‐4‐carboxylate 4. Nitrile 7 derivative of 2 was also obtained by dehydration of 6a in a mixture of SOCl2 and DMF. While cyclocondensation reaction of 2 with hydrazine hydrate leads to the formation of pyrazolo[3,4‐d]pyridazine‐4,7‐dione 8, the reaction of 3 with anhydrous hydrazine provided a new bis pyrazole derivative 9.
Competition between S‐oxidation and nitration in reactions of some β‐ and γ‐quinolinyl sulfides with nitrating mixture
Authors: Maślankiewicz Maria J. , Jaworska Maria , Lodowski Piotr 
Published: March 2009

Abstractmagnified imageThis study was performed in order to explain different orientation in the reaction of quinolinyl sulfides with nitrating mixture, which converted on one hand quinolinyl sulfides 1, 3 and 5 to sulfoxides 2, 4 and 8, respectively, on the other hand, sulfides 6, 7 to the respective nitroderivatives 9 and 10. Competitive experiments showed following reactivity order: thianthrene 11 ≥ thianthrene 5‐oxide 12 ≥ isothioquinanthrene 3 ≥ thioquinanthrene 1 ≥ 3,3′‐diquinolinyl sulfide 5 ≥ 3,4′‐diquinolinyl sulfide 6 ≥ 4,4′‐diquinolinyl sulfide 7. Considering that NO2+ (as reactive form of nitrating mixture) attacks the most electronodonating (sulfur or carbon) center the reactivity order well correlates with the results of HOMO as well as MEP calculations.
Synthesis of beta‐proline like derivatives and their evaluation as sodium channel blockers
Authors: Muraglia Marilena , Franchini Carlo , Corbo Filomena , Scilimati Antonio , Tortorella Vincenzo , Sinicropi Maria Stefania , De Luca Annamaria , De Bellis Michela , Camerino Diana Conte 
Published: March 2009

Abstractmagnified imageA simple and convenient procedure for the preparation of beta‐proline like derivatives in their racemic and optically active forms has been reported. The compounds have been screened for their potential activity as sodium channel blockers.
BF3·Et2O promoted selective synthesis of benzimidazoles
Authors: Rajanarendar E. , Ramesh P. , Rao E. Kalyan , Mohan G. , Reddy A. Siva Rami 
Published: March 2009

Abstractmagnified imageBenzimidazoles 3, 6 and 9 have been synthesized selectively in excellent yields by cyclocondensation of β‐(3‐methyl‐5‐styryl‐4‐isoxazolyl amido) benzoic acids, acrylic acids and propionic acids with 1,2‐phenylene diamines by employing BF3·Et2O as the catalyst. When the same reaction was carried out in pyridine it resulted in mixture of products in each case (3 & 4, 6 & 7 and 9 & 10). Other methods tried by using polyphosphoric acid, HCl, TFA also led to mixtures of 3 & 4, 6 & 7 and 9 & 10 in each case, similar to that of pyridine reaction.
Microwave assisted synthesis of thiazolo[3,2‐b][1,2,4]‐triazoles containing 1,8‐naphthyridine moiety
Authors: Mogilaiah K. , Prashanthi M. , Kavitha S. , Babu H. Sharath 
Published: March 2009

Abstractmagnified imageA simple and efficient protocol for the synthesis of 5‐aryl‐2‐(2‐substituted‐1,8‐naphthyridin‐3‐yl)‐thiazolo[3,2‐b][1,2,4]triazoles (4) is achieved by cyclocondensation of 3‐(2‐substituted‐1,8‐naphthyridin‐3‐yl)‐1,2,4‐triazoles (3) with α‐halogenoketones in anhyd. methanol under microwave irradiation. The products are obtained in good yields and in a state of high purity.
Phenacylsulfonylacetic acid methyl ester‐synthon for 1,2,3‐selena/thiadiazoles and 2H‐diazaphospholes
Authors: Padmavathi Venkatapuram , Mahesh Konda , Thriveni Pinnu , Reddy Tippireddy Venkata Ramana 
Published: March 2009

Abstractmagnified imageA new class of 1,2,3‐selena/thiadiazoles and 2H‐diazaphospholes were synthesized by exploiting α‐ketomethylene group in phenacylsulfonylacetic acid methyl ester.
Reaction of 1‐acylthiosemicarbazides with ethenetetracarbonitrile
Authors: Hassan Alaa A. , Mourad Aboul‐Fetouh E. , Abou‐Zied Ashraf H. 
Published: March 2009

Abstractmagnified image1‐Acylthiosemicarbazides 9a‐d reacted with ethenetetracarbonitrile (TCNE, 2) in ethyl acetate with formation of N′‐(4‐amino‐5,6‐dicyano‐2H‐1,3‐thiazin‐2‐ylidene) substituted hydrazide 10a‐d, N′‐(5‐amino‐3,4‐dicyano‐2H‐pyrrol‐2‐ylidene)‐2‐substituted hydrazide 11a‐d and 2‐substituted imidazo[2,1‐b][1,3,4]‐oxadiazole‐5,6‐dicarbonitrile 12a‐d. Rationales for the conversions observed are presented.
An efficient and greener approach to the synthesis of 3,5‐dicyanopyridin‐2(1H)‐one derivatives in aqueous media under microwave irradiation conditions
Authors: Jia Runhong , Tu Shujiang , Zhang Yan , Jiang Bo , Zhang Junyong , Yao Changsheng , Shi Feng 
Published: March 2009

Abstractmagnified imageA facile and greener synthesis of a series of 3,5‐dicyanopyridin‐2(1H)‐one derivatives was accomplished via the one‐pot reaction of aldehyde, malononitrile and sodium hydroxide in aqueous media under microwave irradiation. This method had several advantages such as shorter route and time, lower cost, reduced environmental impact.
Synthesis and biological study of novel methylene‐bis‐chalcones and substituted methylene‐bis‐pyrimidines/pyrimidinones
Authors: Nagaraj Adki , Reddy Cherkupally Sanjeeva 
Published: March 2009

Abstractmagnified imageA series of novel methylene‐bis‐chalcones was prepared by the reaction of 5,5′‐methylene‐bis‐salicylaldehyde with different acetophenones, subsequent treatment of methylene‐bis‐chalcones with urea/thiourea gave the corresponding methylene‐bis‐pyrimidinones/methylene‐bis‐mercaptopyrimidines in good yields. Characterization of the new compounds has been done by means of IR, 1H NMR, MS and elemental analysis. The antibacterial, antitubercular and antifungal activity of the compounds has also been evaluated.
Studies with enaminones: Formation of a N,O‐cyclicacetal on coupling of 3‐dimethylamino‐1‐hydroxyphenyl‐2‐propenone with arenediazonium salts
Authors: Al‐Zaydi Khadijah M. , Borik Rita M. , Elnagdi Mohamed H. 
Published: March 2009

Abstractmagnified imageCoupling the title compound 3 with arenediazonium salts affords the arylhydrazonochromones 6. The latter compounds react with hydrazine hydrate to yield novel pyrazoles 11.
One‐pot solvent and catalyst‐free synthesis of functionalized 1,8‐naphthyridines and quinolines by microwave irradiation
Authors: Goswami Shyamaprosad , Jana Subrata , Hazra Anita , Adak Avijit Kumar 
Published: March 2009

Abstractmagnified imageA series of functionalized, aryl substituted naphthyridines and quinolines has been synthesized by microwave‐assisted one‐pot two‐component synthesis under solvent‐free conditions in good yields by the reaction of a variety of aryl or heteroaryl amines and aryl vinyl ketones. A combinatorial type approach for a one‐step microwave reaction has been developed where a ring‐closing condensation is followed by a spontaneous aromatization to afford the functionalized aryl substituted 1,8‐naphthyridines and quinolines.
Facile three‐component one‐pot synthesis of indeno‐[1,2‐b]quinolin‐9,11(6H,10H)‐dione derivatives
Authors: Chen Yan , Tu Shujiang , Jiang Bo , Shi Feng 
Published: March 2009

Abstractmagnified imageOne‐pot three‐component cyclocondensation of aldehydes, 1,3‐indanedione and enaminones proceeds in the presence of acetic acid to afford Indeno[1,2‐b]quinolin‐9,11(6H,10H)‐dione derivatives, The method has the advantage of excellent yields(85‐94%) and simple workup procedure.
Synthesis of novel coumarin and benzocoumarin derivatives and their biological and photophysical studies
Authors: Abd‐El‐Aziz Alaa S. , Mohamed Hany M. , Mohammed Shawkat , Zahid Shamsulhaq , Ata Athar , Bedair Ahmed H. , El‐Agrody Ahmed M. , Harvey Pierre D. 
Published: March 2009

Abstractmagnified imageSeveral derivatives of coumarin‐3N‐carboxamides (3‐21) have been prepared via the reaction of the coumarin‐3‐carbonyl chloride (1) with a number of nucleophiles. Novel double‐headed coumarin‐3N‐carboxamides (26‐33) were also produced using the same method. The Pechmann‐Duisberg reaction was applied to prepare new benzo[f]‐ benzo[h]coumarins and 4‐(chloromethyl)‐pyrano[3,2‐c]coumarin‐2‐one (36‐42). The reaction of 1‐chloromethylbenzo[f]coumarins (36) with cyanide anion under different reaction conditions was also investigated in order to assess its suitability for nucleophilic substitution reactions as well as ring transformation products (43‐49). Synthesis of 1‐((benzo[d]thiazol‐2‐yl)methyl)‐9‐hydroxybenzo[f]coumarin (50) represented the first example of methylene bridge‐head heterocyclecontaining benzo[f]coumarin. Some of the newly prepared coumarins exhibited anti‐bacterial activity against Gram Positive and Gram negative bacteria. Compound 36d was found to be active against all the screened bacteria. Photophysical studies were performed on selected fluorescent benzo[f]‐ and benzo[h]coumarin and the quantum yields were also calculated. All new compounds were characterized by IR, MS, 1H and 13C NMR, as well as elemental analysis.
Microwave‐assisted efficient synthesis of benzo[4,5]imidazo[1,2‐a]‐pyrimidine derivatives in water under catalyst‐free conditions
Authors: Tu Shujiang , Shao Qingqing , Zhou Dianxiang , Cao Longji , Shi Feng , Li Chunmei 
Published: March 2009

Abstractmagnified imageBenzo[4,5]imidazo[1,2‐a]pyrimidine derivatives were synthesized via the three‐component reaction of aldehyde, β‐dicarbonyl compound and 2‐aminobenzimidazole in water under microwave irradiation and without catalyst conditions. The new protocol has the advantages of higher yield, lower cost, reduced environment impact, wider scope and convenient procedure.