bluuebunny/crossref_metadata_2025 huggingface dataset:
A facile synthesis of 1‐alkyl‐5‐arylalkoxy‐6‐methoxy‐3,4‐dihydroisoquinolines
Authors: Yim Heong‐Seup , Kim Ho‐Kyun , Kim Jeum‐Jong , Kweon Deok‐Heon , Yoon Yong‐Jin , Lee Sang‐Gyeong , Kim Jung‐Ho
Published: March 2009

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1‐Alkyl‐5‐arylalkoxy‐6‐methoxy‐3,4‐dihydroisoquinolines were synthesized by the alkylation of 1‐alkyl‐5‐hydroxy‐6‐methoxy‐3,4‐dihydroisoquinolines with arylalkyl halide in the presence of potassium carbonate. 1‐Alkyl‐5‐hydroxy‐6‐methoxy‐3,4‐dihydroisoquinolines as key precursor prepared from o‐vaniline via 6 steps.
An efficient synthesis of highly substituted pyrrole and bis pyrrole derivatives
Authors: Sagyam Rajeshwar Reddy , Padi Pratap Reddy , Ghanta Mahesh Reddy , Vurimidi Himabindu
Published: March 2009

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An efficient synthesis of highly substituted pyrrole and bis pyrrole derivatives is reported.
Silica gel / NaHSO4: An efficient and recyclable heterogeneous catalyst for high yield synthesis of 1,5‐benzodiazepine derivatives under microwave irradiation
Authors: Chari M. Adharvana , Shobha D. , Syamasundar K.
Published: March 2009

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Silica gel supported sodium hydrogen sulfate catalyzes efficiently the condensation of o‐phenylenediamines with ketones under microwaves in solvent free conditions to afford the corresponding 1,5‐benzodiazepine derivatives in high yields. Compared to conventional reaction conditions, this new approach consistently has the advantage of excellent yields (90‐98%) and short reaction times of 0.50 – 1.00 min.
Regioselective cyclodehydration of ortho‐hydroxy acetyl aryloxyketones to benzofuran
Authors: Patel Jagdish M. , Soman Shubhangi S.
Published: March 2009

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ortho‐Hydroxy acetyl benzofuran derivatives have been synthesized in a regioselective cyclodehydration of aryloxyketones obtained from β‐resacetophenone and α‐halo ketones.
Synthesis and photophysical properties of N‐styrylazinones
Authors: Cho Su‐Dong , Hwang Jaeyoung , Kim Ho‐Kyun , Yim Heung‐Sup , Kim Jeum‐Jong , Lee Sang‐Gyeong , Yoon Yong‐Jin
Published: March 2009

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N‐Styrylazinones and 1‐styrylbenzotriazine were synthesized, and their photophysical properties were investigated. (Z)‐ and/or (E)‐N‐Styrylazinones (or azine) 4 were prepared from the corresponding heterocycles 1 and benzaldehyde (3) by four methods. The absorption maxima of (Z)‐ and/or (E)‐4a‐4j were measured in four solvents. Their absorption maxima showed a moderate dependence upon solvents. The absorption maxima of (Z)‐isomers were blue‐shifted as compared the corresponding (E)‐isomers. Emission maxima, fluorescence band half‐widths, 0,0 transition energies, Stokes shifts, and quantum yields of (Z)‐ and/or (E)‐4a, 4b, 4d, 4e and 4j were measured in organic solvents. The fluorescence spectra show moderate solvatochroism. The fluorescence properties of N‐styrylheterocycles vary with every heterocycles.
BIFC and QFC promoted rapid and cleaner aromatization of 1,4‐dihydropyridines under solvent‐free condition
Authors: Sivamurugan Vajiravelu , Murugesan Velayutham , Suresh Valiyaveettil , Palanichamy Muthaiyahpillai , Vinu Ajayan
Published: March 2009

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This communication expresses aromatisation of 1,4‐dihydropyridines to pyridine derivatives with the help of alumina supported benzimidazolium fluorochromate (BIFC) and quinolinium fluorochromate (QFC) as oxidants under solvent‐free microwave irradiation. Moderate to excellent yield (80‐98%) of pyridine derivatives were achieved by this methodology.
A facile three‐components, one‐pot synthesis of pyrimido[4,5‐d]pyrimidine‐2,5‐dione derivatives under microwave‐assisted conditions
Authors: Dabiri Minoo , Arvin‐Nezhad Hamid , Khavasi Hamid R. , Bazgir Ayoob
Published: March 2009

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Pyrimido[4,5‐d]pyrimidine‐2,5‐dione derivatives have been synthesized in high yields in a novel, onepot, and efficient process by condensation of 6‐amino‐3‐methyl‐2‐(methylthio)pyrimidin‐4(3H)‐one, aldehydes and urea under microwave‐assisted conditions.
(±)‐2,3‐dialkyl‐1,2,3,4‐tetrahydroquinoline‐3‐carboxylic esters by a tandem reduction‐reductive amination reaction
Authors: Bunce Richard A. , Schammerhorn James E. , Slaughter LeGrande M.
Published: March 2009

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A series of 2‐methyl‐2‐(2‐nitrobenzyl)‐substituted β‐keto ester derivatives has been subjected to reductive cyclization under hydrogenation conditions to assess the importance of the ester group position on the diastereoselectivity of the process. Hydrogenation over 5% palladium‐on‐carbon at 4 atmospheres pressure resulted in formation of (±)‐2,3‐dialkyl‐1,2,3,4‐tetrahydroquinoline‐3‐carboxylic esters with a preference for the product isomer having the C2 alkyl cis to the C3 ester. The product ratios were synthetically useful (6‐16:1), but less than that observed in cyclizations to prepare (±)‐2‐alkyl‐1,2,3,4‐tetrahydroquinoline‐4‐carboxylic esters. The reduced selectivity in the current reactions has been rationalized in terms of the greater conformational mobility around the ester bearing carbon, which decreases the ability of the ester to sterically influence the addition of hydrogen to the final imine intermediate.
One‐pot synthesis of pyrido[2,3‐d]pyrimidines via efficient three‐component reaction in aqueous media
Authors: Shi Daqing , Ji Shunjun , Niu Lihui , Shi Jingwen , Wang Xiangshan
Published: March 2009

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A short and facile synthesis of pyrido[2,3‐d]pyrimidine derivatives was accomplished in good yieldsviathe three‐component reaction of aldehydes, alkyl nitriles and aminopyrimidines in water in the presence of triethylbenzylammonium chloride (TEBAC). The structures of these compounds were characterized by elemental analysis, IR and1H NMR spectra and further confirmed by single crystal X‐ray diffraction analysis.
A general and versatile synthesis of 3‐phenylthio β‐lactams as lead molecules for 3‐methyl‐2‐azetidinones
Authors: Kanwar Seema , Sharma S. D.
Published: March 2009

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Ketene‐imine cycloaddition using phosphorus oxychloride and benzenesulfonyl chloride under the described reaction conditions yielded trans 3‐phenylthio 2‐azetidinones in good yields. Desulfurization using Raney nickel and alkylation finally afforded trans 3‐methyl‐2‐azetidinones in a stereoselective manner.
Synthesis of phenyl furyl sulfides and phenyl furyl ethers by nucleophilic substitution of nitrofurans
Authors: Ogawa Masayuki , Sakuma Katsuya , Okamoto Hiroshi , Koyanagi Jyunichi , Nakayama Kouji , Tanaka Akira , Yamamoto Katsumi
Published: March 2009

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Phenyl furyl sulfides (3a‐j) and phenyl furyl ethers (3k‐n), which are useful in synthesizing furocondensed 3‐ring compounds, can be synthesized by nucleophilic substitution of nitrofurans having electron withdrawal groups. In our experiments using 5‐nitrofurans having electron withdrawal groups (2a‐i), nucleophilic substitution readily occurred with the benzenethiolate anion of thiosalicylic acid (1a), the benzenethiolate anion of thiosalicylate ester (1b), and the phenylate anions of salicylate esters (1c‐d) to yield phenyl furyl sulfides (3a‐j) and phenyl furyl ethers (3k‐n).
Pyridazine and phthalazine derivatives with potential antimicrobial activity
Authors: Butnariu Roxana M. , Caprosu Maria D. , Bejan Vasilichia , Mangalagiu Ionel I. , Ungureanu Margareta , Poiata Antonia , Tuchilus Cristina , Florescu Margareta
Published: March 2009

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Fifteen new pyridazine and phthalazine derivatives were prepared (in good to excellent yields) and tested in vitro as antimicrobial compounds. All the compounds have proved to have a remarkable activity against Gram positive germs, the results on Sarciria Luteea being spectacular. Correlation structure ‐ biological activity have been done. Stereo‐ and region‐ chemistry involved in these reactions are discussed.
Microwave assisted regiospecific synthesis of 5‐trifluoromethyl‐4,5‐dihydropyrazoles and—pyrazoles
Authors: Martins Marcos A. P. , Pereira Claudio M. P. , Moura Sidnei , Frizzo Clarissa P. , Beck Paulo , Zanatta Nilo , Bonacorso Helio G. , Flores Alex F. C.
Published: March 2009

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The regiospecific synthesis of a series of twelve 5‐trifluoromethyl‐4,5‐dihydropyrazoles and ‐pyrazoles from the cyclocondesation reaction of 4‐alkoxy‐1,1,1‐trifluoro‐3‐alken‐2‐ones [F3CC(O)CH=C(R1)OR, where R1 = Me, Et, Pr, iso‐Pr, Bu, iso‐Bu, Ph, H; and R = Me, Et] with phenylhydrazine in toluene by environmentally benign microwave induced techniques is reported. It is shown that under appropriated conditions, the variation of microwave irradiation power leads to 4,5‐dihydropyrazole or pyrazole derivatives. This paper also includes the use of montmorillonite K‐10 as a solid support for the synthesis of pyrazoles under solvent free conditions.
The synthesis of some 3‐acylindoles revisited
Authors: Hasimbegovic Vedran , Slätt Johnny , Bergman Jan , Janosik Tomasz
Published: March 2009

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A study probing the scope of acylation of indoles with dicarboxylic acids in acetic anhydride has been performed, resulting in products incorporating 3‐acylindole‐ or 1‐acylindole motifs depending on the choice of the acid reactant. Synthetically useful results were only obtained from reactions involving malonic acid or Meldrum's acid. Correlations to previous studies have also been made and discussed.
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

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Long‐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

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The 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

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Reaction 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

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An 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

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A 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

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Some 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

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Different 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

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One‐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

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A 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

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The 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

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We 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

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A 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

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A 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

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An 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

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Furanyl 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

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A 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

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cis,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

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Treatment 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

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Stepwise 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

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1,3‐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

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Select 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

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A 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

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Three 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

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Several 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

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High 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

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Novel 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

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Some 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

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This 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

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4‐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

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1‐[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

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A 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.
Synthesis of a novel water‐soluble NMDA receptor antagonist
Authors: Masuko Takashi , Kusama Tadashi , Nagaoka Hiroki , Metori Koichi , Kizawa Yasuo , Miyake Muneharu
Published: March 2009

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A novel water‐solubleN‐methyl‐D‐aspartate (NMDA) receptor antagonist ATGDMAP1as synthesized and the effect of1on NMDA receptors was studied using voltage‐clamp recordings of recombinant NMDA receptors expressed inXenopusoocytes. The compound1inhibited macroscopic currents in NR1/NR2A, NR1/NR2B, NR1/NR2C and NR1/NR2D receptor subtypes in oocytes voltage‐clamped at ‐70 mV. Mutant NR1/NR2B receptors containing NR1(T648A) or NR1(T648S) had very large holding currents when voltage‐clamped at ‐70 mV compared to that of wild‐type NMDA receptors, because these mutants generate constitutively open channels. ATGDMAP1and Mg2+, a channel blocker of the NMDA receptor, reduced the large holding currents needed for mutant NMDA receptors. These data indicate that ATGDMAP1directly acts on the channel pores of the NMDA receptor.
The synthesis and fluorescence of novel N‐substituted‐1,8‐naphthylimides
Authors: Yuan Dongwu , Brown Robert G , Hepworth John D , Alexiou Michael S , Tyman John H. P.
Published: March 2009

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The synthesis and characterisation of a series of novel 4‐acylamino and 4‐alkylamino‐N‐1,8‐naphthalimides is described. The UV‐visible absorption and emission properties of the compounds are reported. Significant solvent effects are noted for 4‐n‐butyl‐9‐n‐butyl‐1,8‐naphthylimide. The incorporation of acetyl and chloroacetyl groups into the 4‐substituent markedly increases the fluorescence quantum yield compared with 4‐alkylamino substituemnts.
Green and high efficient synthesis of triaza‐benzo[b]fluoren‐6‐one derivatives in water under microwave irradiation
Authors: Shao Qingqing , Tu Shujiang , Li Chunmei , Cao Longji , Zhou Dianxiang , Jiang Bo , Zhang Yan , Hao Wenjuan , Wang Qian
Published: March 2009

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Triaza‐benzo[b]fluoren‐6‐one derivatives were synthesized via the three‐component reaction of aldehyde, cyclohexane‐1,3‐dione compound and 2‐aminobenzimidazole in water under microwave irradiation. The new protocol has the advantages of excellent yield, low cost, reduced environment impact, wide scope and convenient procedure.
New route for preparation of nitrosubstituted 1,2‐phenylenediamines
Authors: Bella MaroŠ , Milata Viktor
Published: March 2009

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4‐Nitrobenzoselenadiazole was methylated with dimethylsulphate to give corresponding 1‐N‐methyl‐4‐nitrobenzoselenadiazolium methylsulphate which after alkaline ring‐opening afforded 1‐N‐methyl‐3‐nitro‐1,2‐phenylenediamine in 90% yield. This compound was also prepared from 3‐nitro‐1,2‐phenylenediamine by monomethylation through tosylation, methylation and detosylation and was confirmed and characterised as 1‐methyl‐4‐nitrobenzimidazole. Methylation of 5‐nitrobenzoselenadiazole and subsequent alkaline ring‐opening led to unseparable mixture of both methylated products.
Synthesis of 1,3‐oxazole and benzimidazole pendant groups from polyacrylonitrile hydrolysis products
Authors: Vega Isabel N. , Sánchez Leonardo , D'Accorso Norma
Published: March 2009

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New terpolymers containing heterocyclic pendant groups, such as 1,3 oxazole and benzimidazole are obtained by hydrolysis of polyacrylonitrile (PAN). These materials are spectroscopically characterized and their solubility, viscosity and thermal behavior are analyzed.
Kinetic study ofmeso‐tetraphenylporphyrin synthesis under microwave irradiation
Authors: De Paula Rodrigo , Faustino Maria A. F. , Pinto Diana C.G.A. , Neves Maria G.P.M.S. , Cavaleiro José A. S.
Published: March 2009

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A typical synthesis ofmeso‐tetraphenylporphyrin was carried out from condensation of pyrrole with benzaldehyde in acidic medium under microwave irradiation. A batch of tests were carried out and a systematic evaluation of organic acid, reactant concentration, microwave power, time of reaction, presence of added oxidant at normal pressure conditions and in closed vessels system, allowed us to find a good set of conditions within the range of study. The best result was achieved in only 5 minutes of irradiation showing a great reduction in reaction time and reaching yields higher than those mentioned in literature for the synthesis under classical synthetic heating method.
Synthesis of 2,4‐difuryl‐4H‐3,1‐benzothiazines via a furan ring migration reaction
Authors: Abaev Vladimir T. , Tsiunchik Fatima A. , Butin Alexander V. , Gutnov Andrey V.
Published: March 2009

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A new simple synthetic approach to 2,4‐difuryl‐4H‐3,1‐benzothiazines from 2‐isothiocyanoaryldifuryl‐methanes in the presence of acidic catalyst is described. This rearrangement is a new example of furan ring migration reaction resulting from intramolecular attack with electrophilic carbon.
High pressure‐assisted synthesis of 1,2,3‐trialkyldiaziridines from N‐chloroalkylamines
Authors: Kuznetsov Vladimir V. , Syroeshkina Julia S. , Moskvin Dmitrii I. , Struchkova Marina I. , Makhova Nina N. , Zharov Alexey A.
Published: March 2009

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New method for the preparation of 1,2,3‐trialkyldiaziridines 1 in high yields, based on the transformation of N‐chloroalkylamines 3 without using carbonyl compounds in the presence of primary aliphatic amines with the same alkyl fragment, potassium carbonate and a small amount of water in CHCl3 under high pressure (500 MPa), was developed. Diaziridines 1 can be synthesized in the same conditions using a larger amount of potassium carbonate instead of primary aliphatic amines however in lower yields. The kinetic investigations on the synthesis of 1,2‐diethyl‐3‐methyldiaziridine 1a from N‐chloroethylamine 3a have shown that the reaction leading to diaziridine 1a proceeds according to the law of the second order.
Syntheses of oxazolo[4,5‐c]pyridine and 6‐azaindole
Authors: Tjosaas Freddy , Kjerstad Ivar Broendbo , Fiksdahl Anne
Published: March 2009

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The preparation of oxazolo[4,5‐c]pyridine and 6‐azaindole from 4‐bromo‐3‐pivaloylaminopyridine (8) is reported. The oxazolopyridine 2‐tert‐butyl‐oxazolo[4,5‐c]pyridine (9) was successfully prepared from 8 in 78% yield by a new base/TBAB promoted non‐catalyzed microwave cyclisation strategy (10 min) or, alternatively, in 54% yield by conventional heating (48 hrs) and CuI catalysis. The 6‐azaindole 2‐phenyl‐1‐(trimethylacetyl)‐6‐azaindole (13) was prepared from 8 in a two step procedure, including a Sonogashira coupling reaction.
Synthesis of 2‐alkyl‐4,5‐aryl‐2H‐[1λ6,2,3,6]‐thiatriazine‐1,1‐dioxides
Authors: Hilp M.
Published: March 2009

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Sulphamoyl chlorides and chlorosulphonyl isocyanate react with monosubstituted hydrazones and alkylhydrazonates to sulphamoyl hydrazones and sulphamoyl hydrazonates respectively. Reaction of benzil monoalkylhydrazones with chlorosulphonyl isocyanate results in formation of 2‐alkyl‐4,5‐aryl‐2H‐ [1λ6,2,3,6]‐thiatriazine‐1,1‐dioxides.
Synthesis of trifluoromethyl‐1,2,4‐triazine‐ and trifluoromethylpyrimidine‐fused uracils
Authors: Takahashi Masahiko , Akiyama Kazuhiko , Suzuki Takumi , Inoue Hiroshi
Published: March 2009

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A variety of trifluoromethyl‐1,2,4‐triazine‐ and trifluoromethylpyrimidine‐fused uracils (9), (12), (15) and (18) were synthesized from trifluoroacetaldehyde ethyl hemiacetal or trifluoroacetic anhydride and corresponding uracil derivatives.
Microwave‐assisted döbner synthesis of 2‐phenylquinoline‐4‐carboxylic acids and their antiparasitic activities
Authors: Muscia Gisela C. , Carnevale Juan P. , Bollini Mariela , Asís Silvia E.
Published: March 2009

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A series of twelve substituted 2‐phenylquinoline‐4‐carboxylic acids analogous to antimalarial and antileishmanial natural products was developed via the Döbner reaction employing microwave irradiation (MW). The products were obtained in moderate yields in 0.5‐3 minutes and nine of them were evaluated in vitro against the parasites responsible for malaria, leishmaniasis and trypanosomiasis diseases (WHO, Switzerland). Four compounds exhibited activity against Trypanosoma cruzi and another two resulted active against Plasmodium falciparum and Leishmania infantum, respectively.
Synthesis of new thiazolidine and imidazolidine derivatives of pharmacological interest
Authors: El‐Aasar Nadia K. , Saied Khaled F.
Published: March 2009

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The hitherto unknown 5‐(2‐aryl‐2‐oxoethyl)‐4‐oxo‐1,3‐thiazolidines 1a‐l have been synthesized viacycloaddition process between thiourea and/or its derivatives with 3‐aroylpropenoic acids. 1H NMR spectra revealed the presence of 1a‐c as a tautmeric mixture. The presence of the thiazoline tautmers (1a‐c)′ was confirmed by methylating the tautmeric mixture, to the respective methylated derivatives 2‐N‐methylanilino‐5‐(2‐aryl‐2‐oxoethyl)‐4‐oxo‐1,3‐thiazolines2a‐c and 1g‐i. Acidic treatment of 1 provided the respective 2‐oxo homologues 3a‐i. When 1a‐d, k were refluxed with DMF, molecular rearrangement was achieved, providing the 4‐oxo‐2‐thioxoimidazolidine isomers4a‐d, k. Bromination of 4a and 4d in hot acetic acid afforded the respective (E,Z)‐5‐benzoylmethylene derivatives 5a,d which were prepared authentically. Thiation of 1a‐c and 4a‐c gave 5‐aryl‐2,3‐dihydro‐2‐phenyliminothieno[2,3‐d]thiazoles 6a‐cand 1‐phenyl‐5‐aryl‐2,3‐dihydro‐2‐thioxothieno[2,3‐d]imidazoles 7a‐c, respectively. The proposed structures have been confirmed by elemental analysis and spectroscopic data. The selected products showed different antimicrobial effect.
An efficient synthesis of polyhydroacridine derivatives by the three‐component reaction of aldehydes, amines and dimedone in ionic liquid
Authors: Shi Da‐Qing , Ni Sai‐Nan , Fang‐Yang  , Shi Jing‐Wen , Dou Guo‐Lan , Li Xiao‐Yue , Wang Xiang‐Shan
Published: March 2009

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In this paper the preparation of 3,3,6,6‐tetramethyl‐9,10‐diaryl‐1,2,3,4,5,6,7,8,9,10‐decahydroacridine‐1,8‐dione derivatives from aldehydes, aromatic amines and 5,5‐dimethyl‐1,3‐cyclohexanedione in 1‐n‐butyl‐3‐methylimidazolium bromide ([bmim]Br) is described. The structures of these compounds were characterized by elemental analysis, IR and1H NMR spectra and further confirmed by single crystal X‐ray diffraction analysis.
One‐pot synthesis of angular furocoumarins: A simple protocol involving unprecedented intramolecular aldol condensation
Authors: Dutta Lakshmi Narayan , De Banani , Patra Amarendra
Published: March 2009

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Refluxing of hydroxycoumarinyl ketones with methyl γ‐bromocrotonate in dry acetone in presence of anhydrous K2CO3 afforded substituted angelicins (angular furanocoumarins) in satisfactory yields through intramolecular Aldol condensation followed by β‐elimination.
Synthesis and pharmacological investigation of novel 4‐(4‐Ethyl phenyl)‐1‐substituted‐4H‐[1,2,4]triazolo[4,3‐a]‐quinazolin‐5‐ones as new class of H1‐antihistaminic agents
Authors: Alagarsamy V. , Parthiban P. , Solomon V. Raja , Dhanabal K. , Murugesan S. , Saravanan G. , Anjana G. V.
Published: March 2009

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A series of novel 4‐(4‐ethylphenyl)‐1‐substituted‐4H‐[1,2,4]triazolo[4,3‐a]quinazolin‐5‐ones were synthesized by the cyclization of 2‐hydrazino intermediate with various electrophile. The starting material 2‐hydrazino compound was synthesized from 2‐ethyl aniline by a new innovative route with improved yield. When tested for theirin vivoH1‐antihistaminic activity on conscious guinea pigs, all the test compounds significantly protected the animals from histamine induced bronchospasm. The compoundIIemerged as the most active compound of the series and it is more potent (73.93% protection) when compared to the reference standard, chlorpheniramine maleate (71% protection), it showed negligible sedation (10%) when compared to chlorpheniramine maleate (30%). Therefore compoundIIwill serve as prototype molecule for further development as a new class of H1‐antihistamines
Electrophilic aromatic substitution of 3‐alkoxy‐6‐alkyl‐2‐cyano‐4,5,6a,11‐tetraazabenzo[a]fluorene with orthoesters
Authors: Okamoto Yoshihisa , Yamaguchi Yoshimi , Maeda Mitsuaki , Kurasawa Yoshihisa
Published: March 2009

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Fused tetracycles, 6‐alkyl‐3‐alkoxy‐2‐cyano‐4,5,6a,11‐tetraazabenzo[a]fluorene derivatives (5a,b,c,d,e,f), are synthesized from 2‐alkoxy‐5‐(benzimidazol‐2‐ylidene)‐3‐cyano‐6‐imino‐5,6‐dihydro‐pyridines (4b,c), and when refluxed in ethyl orthoacetate or ethyl orthopropionate, the elecrophilic aromatic substitution occurs at the ortho position of the cyanopyridine ring in the fused tetracycles (5b,c,e,f) to afford 6‐alkyl‐3‐alkoxy‐2‐cyano‐1‐ethyl‐4,5,6a,11‐tetraazabenzo[a]fluorenes(6b,c,e,f).
Gas‐phase thermolysis of benzotriazole derivatives. Part 4. Pyrolysis of 1‐acylbenzotriazole phenylhydrazones. Interesting direct routes towards N‐aminobenzimidazoles
Authors: Al‐Awadi Hanan , Ibrahim Maher R. , Al‐Awadi Nouria A. , Ibrahim Yehia A.
Published: March 2009

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Flash vacuum pyrolysis (FVP) of 1‐acylbenzotriazole phenylhydrazones gave benzonitriles, aniline and 2‐arylbenzimidazole derivatives. Static pyrolysis of the same substrates at 180 °C gave exclusively the corresponding N‐anilino‐2‐arylbenzimidazole derivatives. Pyrolysis of the isomeric 2‐acylbenzotriazole phenylhydrazones gave similar products.
Barium nitrate catalyzed one pot synthesis of 1,4‐dihydropyridines under solvent free conditions at room temperature
Authors: Sharma Mukul , Agarwal Nisha , Rawat Diwan S.
Published: March 2009

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Barium nitrate acts as an efficient catalyst for the three‐component one pot synthesis of 1,4‐dihydropyridines. Barium nitrate is a safe chemical, and reaction without the use of organic solvents makes the process eco‐friendly.
Microwave assisted synthesis of novel 6,7,8‐trimethoxy N‐substituted‐4‐aminoquinazoline compounds
Authors: Liu Gang , Sun Lin , Liu Chunping , Ji Chunnuan , Wen Quanwu , Ma Songmei
Published: March 2009

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A fast, efficient and convenient reaction of 6,7,8‐trimethoxy‐4‐chloroquinazoline and aryl (or benzyl) amines was achieved under microwave irradiation in isopropyl alcohol, providing a simple method for synthesis of novel 6,7,8‐trimethoxy N‐substituted‐4‐aminoquinazoline compounds in good yield in short time. The title compounds were evaluated for their in vitro anti‐proliferative activities against PC3 cell by MTT method.
Fused pyridines by a tandem aza‐wittig / heterocyclization strategy: Synthesis of 1,2,4‐triazolo[1,5‐a]pyridines and pyrido[1,2‐b][1,2,4]triazines
Authors: Barsy Magda A. , El Rady Eman A. , El Latif Fawi M. Abd
Published: March 2009

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The iminophosphorane 1‐amino‐6‐(triphenylphosphoranylideneamino)‐2‐oxo‐4‐phenyl‐1,2‐dihydro‐pyridine‐3,5‐dicarbonitrile 2 prepared from 1,6‐diaminopyridine 1 reacts with heterocumulenes such as carbon disulfide and phenylisocyanate, and with acid chlorides, acid anhydrides and haloketones to give directly the title compounds in an one‐pot aza‐Wittig / heterocyclic‐ring closure process with good yields.