Chem.

Distribution by Scientific Domains


Selected Abstracts


Striatal modulation of cAMP-response-element-binding protein (CREB) after excitotoxic lesions: implications with neuronal vulnerability in Huntington's disease

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2006
Carmela GiampÓ
Abstract Recent evidence has shown that the activity of cAMP responsive element-binding protein (CREB) and of CREB-binding protein (CBP) is decreased in Huntington's disease (HD) [Steffan et al. (2000)Proc. Natl Acad. Sci. USA, 97, 6763,6768; Gines et al. (2003)Hum. Mol. Genet., 12, 497,508; Rouaux et al. (2004) Biochem. Pharmacol., 68, 1157,1164; Sugars et al. (2004)J. Biol. Chem., 279, 4988,4999]. Such decrease is thought to reflect the impaired energy metabolism observed in a HD mouse model, where a decline in striatum cAMP levels has been observed [Gines et al. (2003)Hum. Mol. Genet., 12, 497,508]. Increased levels of CREB have also been demonstrated to exert neuroprotective functions [Lonze & Ginty (2002)Neuron, 35, 605,623; Lonze et al. (2002)Neuron, 34, 371,385]. Our study aimed to investigate the distribution of CREB in the neuronal subpopulations of the striatum in normal rats compared to the HD model of quinolinic acid lesion. Twenty-five Wistar rats were administered quinolinic acid 100 mm into the right striatum, and killed after 24 h, 48 h, 1 week, 2 weeks, and six weeks, respectively. The contralateral striata were used as controls. Dual-label immunofluorescence was employed using antibodies against phosphorylated CREB and each of the different neuronal subpopulations markers. Our results show that activated CREB levels decrease progressively in projection neurons and parvalbumin (PARV) and calretinin (CALR) interneurons, whereas such levels remain stable in cholinergic and somatostatin interneurons. Thus, we speculate that the ability of cholinergic interneurons to maintain their levels of CREB after excitotoxic lesions is one of the factors determining their protection in Huntington's disease. [source]


Stereochemical Models for Discussing Additions to ,,, -Unsaturated Aldehydes Organocatalyzed by Diarylprolinol or Imidazolidinone Derivatives , Is There an ,(E)/(Z)-Dilemma'?

HELVETICA CHIMICA ACTA, Issue 4 2010
Dieter Seebach
Abstract The structures of iminium salts formed from diarylprolinol or imidazolidinone derivatives and ,,, -unsaturated aldehydes have been studied by X-ray powder diffraction (Fig.,1), single-crystal X-ray analyses (Table,1), NMR spectroscopy (Tables,2 and 3, Figs.,2,7), and DFT calculations (Helv. Chim. Acta2009, 92, 1, 1225, 2010, 93, 1; Angew. Chem., Int. Ed.2009, 48, 3065). Almost all iminium salts of this type exist in solution as diastereoisomeric mixtures with (E)- and (Z)-configured +NC bond geometries. In this study, (E)/(Z) ratios ranging from 88,:,12 up to 98,:,2 (Tables,2 and 3) and (E)/(Z) interconversions (Figs.,2,7) were observed. Furthermore, the relative rates, at which the (E)- and (Z)-isomers are formed from ammonium salts and ,,, -unsaturated aldehydes, were found to differ from the (E)/(Z) equilibrium ratio in at least two cases (Figs.,4 and 5,,a, and Fig.,6,,a); more (Z)-isomer is formed kinetically than corresponding to its equilibrium fraction. Given that the enantiomeric product ratios observed in reactions mediated by organocatalysts of this type are often ,99,:,1, the (E)-iminium-ion intermediates are proposed to react with nucleophiles faster than the (Z)-isomers (Scheme,5 and Fig.,8). Possible reasons for the higher reactivity of (E)-iminium ions (Figs.,8 and 9) and for the kinetic preference of (Z)-iminium-ion formation are discussed (Scheme,4). The results of related density functional theory (DFT) calculations are also reported (Figs.,10,13 and Table,4). [source]


Erratum: J. Basic Microbiol.

JOURNAL OF BASIC MICROBIOLOGY, Issue 4 2009
4/200
As came to our knowledge, the evidence for a new spiroketal produced by Aspergillus niger isolated from an opuntia by Wu et al. (Journal of Basic Microbiology 2008, 48 (2008), 140,142; DOI 10.1002/jobm.200700363) does not preclude identity with a previously published compound from Aspergillus niger, terrineol (Macedo Jr., F.C. et al., Tetrahedron Lett., 45 (2004), 53, and Macedo Jr., F.C. et al., Magn. Reson. Chem., 43 (2005), 251). The authors failed to discuss this possibility (ę 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Synthesis and crystal structure of 3,5-diacetyl-4-methylpyrazole

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Moha Outirite
The 3,5-diacetyl-4-methylpyrazole diketone has been synthesized and its crystal structure has been determined. This diketone reacts with hydroxylamine hydrochloride to give the dioxime derivative. This reaction, conducted in presence of copper II ions, leads to the formation of L2M2 copper II complexes. J. Heterocyclic Chem., (2010). [source]


One-pot synthesis of spiro[diindeno[1,2- b:2,,1,- e]pyridine-11,3,-indoline]-triones

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Ramin Ghahremanzadeh
A one-pot and pseudo four-component synthesis of spiro[diindeno[1,2- b:2,,1,- e]pyridine-11,3,-indoline]-trione derivatives by cyclo-condensation reaction of isatins, 1,3-indandione, and ammonium acetate in refluxing acetic acid is reported. J. Heterocyclic Chem., (2010). [source]


A practical and stereoselective synthesis of (+/,)- trans -4-benzyloctahydropyrrolo[3,4- b][1,4]oxazine

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Daniel P. Walker
trans -Octahydropyrrolo[3,4- b][1,4]oxazine is an important heterocycle within the pharmaceutical industry for the preparation of biologically active analogs, including the phase III drug, finafloxacin. A practical synthesis of the title compound (2) is described in eight steps and ca. 10% overall yield. The key synthetic step is the formation of the pyrrolo[3,4- b][1,4]oxazine core 20via a one pot double N -alkylation of the corresponding bis-tosylate 18 with 4-nitrobenzenesulfonamide. Subsequent removal of the nosyl group occurred under mild conditions. J. Heterocyclic Chem., (2010). [source]


Microwave-assisted synthesis of quinolone derivatives and related compounds

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Suhas Pednekar
The Gould-Jacob type of reaction for the synthesis of ethyl 5-ethyl-8-oxo-5,8-dihydro-[1,3]-dioxolo[4,5-g]quinoline-7-carboxylate 4 has been carried out conventionally by the condensation between N -ethyl-3,4-methylenedioxyaniline 1 and diethyl ethoxymethylenemalonate 2 gave the unsaturated ester 3 and thermal cyclization in refluxing diphenyl oxide gave quinolone ethyl ester 4 and the results obtained were compared with single step microwave irradiation under solvent free conditions for the synthesis of 4. The esters on basic hydrolysis formed free acid 5, which, upon treatment with thionyl chloride gave the acid chloride 6. Treatment of acid chloride with o -phenylenediamine, hydrazine hydrate, ammonia, urea, and thiourea gave the amides (7,11). CS2 treatment in presence of KOH on 8 gave 12. We prepared 7,12 derivatives by conventional as well as microwave irradiation. These compounds have been characterized on the basis of IR, 1H NMR, MS, and elemental analysis. All the compounds prepared herein were screened for their antibacterial activity. Compounds 4, 5 possess promising antibacterial activity and compound 8 showed significant antibacterial activity. J. Heterocyclic Chem., (2010). [source]


Promising antimicrobial agents: Synthetic approaches to novel tricyclic and tetracyclic pyrimidinones with antimicrobial properties

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Hatem M. Gaber
New tricyclic pyrimidinone derivatives were obtained from the corresponding thiazolopyrimidinone or hydrazino systems. The annelation of tricyclic hydrazino compound with 1,2,4-triazole and tetrazole moieties gave novel tetracyclic condensed pyrimidinones. The investigation of the antimicrobial properties of tricyclic and tetracyclic pyrimidinones, by agar-well diffusion assay, was carried out against six pathogenic bacteria (Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella spp, and Salmonella typhyrium) and four pathogenic fungi (Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus, and Trichderma horozianum). Most of the compounds tested exhibited some degree of antimicrobial activity against microorganisms. Among these compounds, 4-benzylidenhydrazino-8-cyano-7-(furan-2-yl)thiazolo[3,2- a:4,5- d,]dipyrimidin-9-one (12) showed the most favorable antibacterial activity, while compound 17 showed the highest effect on fungi. Interestingly, tetrazole derivative 19 displayed a remarkable effect on fungi much more than the corresponding 3-substituted triazole derivatives on the one hand, whereas the lowest effect on bacteria on the other. J. Heterocyclic Chem., (2010). [source]


The reaction of 3,4-dihydro-2H-pyran with oxalyl chloride: Formation and crystal structure analysis of an unexpected bicyclic product

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Bernd Schmidt
3,4-Dihydro-2-H-pyran and oxalyl chloride react, depending on the conditions, to keto esters, a pyran-3-carboxylic acid or derivatives thereof, or to an hitherto unknown bicyclic acetal containing a vinyl chloride moiety. The structure of the latter product has been unambiguously elucidated by single-crystal X-ray structure analysis. A mechanism for its formation is proposed. J. Heterocyclic Chem., (2010). [source]


Ester- and ketone-substituted (▒)-1-alkyl-6-nitro-1,2,3,4-tetrahydroquinolines by a tandem SNAr-Michael reaction

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Richard A. Bunce
A synthesis of ester- and ketone-substituted (▒)-1-alkyl-6-nitro-1,2,3,4-tetrahydroquinolines has been developed from 2-pentenoates and 2-penten-1-ones substituted at C5 by a 2-fluoro-5-nitrophenyl group. The cyclization involves an SNAr reaction followed by a Michael addition that occurs exo to the final ring. A previously reported version of this annulation proceeded by an initial endo Michael addition (acceptor became part of the final ring) followed by an SNAr ring closure. The current reactions proceed in 82,97% yields in DMSO using primary amines that are unbranched at the , carbon. The synthesis of the reaction substrates as well as process optimization, mechanistic studies to elucidate the reaction chronology and comparisons with the endo Michael variant are presented. J. Heterocyclic Chem., (2010). [source]


A convenient one-pot procedure for the synthesis of 2-aryl quinazolines using active MnO2 as oxidant

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Yi-Yuan Peng
A variety of 2-aryl quinazolines were synthesized from the condensation of 2-aminobenzylamines and aryl aldehydes to form 2-aryl-1,2,3,4-tetrahydroquinazolines and subsequent oxidation of the intermediates with MnO2. J. Heterocyclic Chem., (2010). [source]


Sulfamic acid-catalyzed synthesis of 13-aryl-indeno[1,2- b]-naphtha[1,2-e]pyran-12(13H)-ones under solvent-free conditions

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2010
Li Qiang Wu
The reaction of ,-naphthol with arylaldehydes and 2H-indene-1,3-dione in the presence of sulfamic acid (3 mol %) under solvent-free conditions led to 13-aryl-indeno[1,2- b]naphtho[1,2- e]pyran-12(13H)-ones in good yields. J. Heterocyclic Chem., (2010). [source]


Chemistry and heterocyclization of dithiobiurea and thioureidoalkylthiourea

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010
Alaa A. Hassan
This review summarizes published data on the behavior and reactions of dithiobiurea and thioureidoalkylthiourea derivatives, which lead to the formation of heterocyclic systems, including methods of preparation in addition to synthesis of imidazolidine, thiazole, thioazolidine, triazolidine, thiadiazine, and spiro compounds. J. Heterocyclic Chem., (2010). [source]


Synthetic strategies in the construction of chromones

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010
Nian-Guang Li
Because of important biological applications of chromones, some synthetic strategies leading to more complex derivatives have been widely explored in the past years. Thus, the purpose of this review is to report some recent improvements of the classical synthetic methods and of some nonclassical methods to obtain simple oxygenated chromones. The strategies for synthesis of heterocycle analogs containing phosphorus, nitrogen, and sulfur are also summarized. J. Heterocyclic Chem., (2010). [source]


An efficient and highly selective method for the synthesis of cryptotackiene derivatives catalyzed by iodine

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010
Xiang-Shan Wang
A mild, efficient and highly selective approach to the synthesis of cryptotackiene derivatives via three-component reactions of 3-amino-9-ethylcarbazole and aromatic aldehydes with electron-rich alkenes, such as 2,3-dihydrofuran, or 3,4-dihydro-2H -pyran catalyzed by iodine in THF is reported. It is worth to note that only trans -products were obtained with high selectivity in good to high yields, which confirmed by X-ray diffraction analysis. J. Heterocyclic Chem., (2010). [source]


A simple and versatile protocol for the preparation of 1,3-functionalized heterocycles utilizing benzoylpyruvates

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010
Jens M. J. Nols÷e
Acid-mediated condensation between benzoylpyruvates and various dinucleophiles in alcoholic solvent furnished the heterocyclic imprint in moderate to good yield. Combining a range of symmetric as well as nonsymmetric nitrogen/nitrogen or nitrogen/carbon centered dinucleophiles resulted in excellent regioselectivity. ,-Difunctionalized fused pyrimidines, pyridazines, and pyridines were produced in this manner. The protocol was designed to obviate chromatographic purification. J. Heterocyclic Chem., (2010). [source]


Copper-catalyzed alkyne cycloaddition on electron deficient azides via tetrazolo[1,5- a]pyrimidines

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010
Linda I. Nilsson
Tetrazolo[1,5- a]pyrimidines are capable of serving as masked azides in copper-catalyzed Huisgen cyclization with a variety of terminal alkynes, providing a simple protocol for the generation of novel 4,-substituted 2-(1,,2,,3,-triazol-1,-yl)pyrimidines. J. Heterocyclic Chem., (2010). [source]


One-pot synthesis of new spiro[cyclopropane-1,3,-[3H]indol]-2,(1,H)-ones from 3-phenacylideneoxindoles

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010
Masoud Shaabanzadeh
In a one-pot procedure, the 3-phenacylideneoxindoles 1a,d were reacted with hydrazine and then in situ with lead(IV) acetate and new diastereoisomers of spiro[cyclopropane-1,3,-[3H]indol]-2,(1,H)-ones were prepared. Compounds 1a,d underwent a highly diastereoselective cyclopropanation leading to diastereoisomers 2a,d. These new compounds containing both 2-oxindole and cyclopropane moieties may be valuable in medicinal chemistry. J. Heterocyclic Chem., (2010). [source]


Synthesis of isomeric 2,3,5-trisubstituted perhydropyrrolo[3,4-d]-isoxazole-4,6-diones via 1,3-dipolar cycloaddition reactions

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2010
Hamdi Ízkan
A series of isoxazolidine derivates (isomeric 2,3,5-trisubstitutedperhydropyrrolo[3,4-d]isoxazole-4,6-diones) used as anti-inflammatory, immunosuppressive, antibacterial agent, and inhibitor for some enzymes were synthesized. These compounds were prepared by 1,3-dipolar cycloaddition of N -methyl maleimide and N -phenyl maleimide with nitrones. Diastereomeric products obtained in this reaction were separated by column chromatography and recrystallized. All compounds synthesized were characterized by elemental analysis and spectroscopic methods (1H NMR, 13C NMR, and FTIR). J. Heterocyclic Chem., (2010). [source]


Selectivity of N -aroyl- N,-arylthioureas towards 2-(1,3-dioxo-1H -inden-2(3H)-ylidene)malononitrile.

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
2- d][, 3]- thiazepin-2(6H)-ylidene)-4-arylamides of antitumor, New synthesis of (Z)- N -((E)-4-amino-1-aryl-5-cyano-6-oxo-1H -indeno[, antioxidant activities
The reaction between N -aroyl- N,-arylthioureas with 2-(1,3-dioxoindan-2-ylidene)malononitrile furnished indeno[1,2- d][1,3]thiazepines in 70,85% yields. The mechanism of the products' formation is discussed. Some of the products showed effective antitumor and antioxidant activities. The results revealed that compound indenothiazepine derivative showed a high inhibition of the cell growth of Hep-G2 cells is compared with the growth of untreated control cells, as concluded from their low IC50 value 21.73 ,M. On the other hand, two indenothiazepine derivatives have an effective antioxidant activity with SC50 values of 62.5 mM and 87.4 mM, respectively. J. Heterocyclic Chem., (2010). [source]


Synthesis of 14-aryl-14H -dibenzo[a,j]xanthenes catalyzed by acyclic acidic ionic liquids

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
Dong Fang
Some recyclable acyclic SO3H-functionalized ionic liquids have been used as novel catalysts for the synthesis of 14-aryl-14H -dibenzo[a,j]xanthenes via the one-pot condensation of ,-naphthol and aromatic aldehydes in aqueous medium. The condensation reaction was accomplished successfully with various aromatic aldehydes with good to excellent yields ranged from 86 to 96% within 5,30 min. After the reaction, the products could simply be separated from the catalysts by filtration. When separated from the reaction mixture, the catalysts could be recycled and reused for several times without noticeably reducing catalytic activity. The methodology gives the advantages of high yields, short reaction time, and easy work-up procedure. J. Heterocyclic Chem., (2010). [source]


Novel 2-hydrazino-pyrimidin-4(3H)-one derivatives as potential dihydrofolate reductase inhibitors

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
Mariam S. Degani
Novel substituted 2-hydrazino-pyrimidin-4(3H)-one derivatives were synthesized and examined for their antifolate activity against DHFR from Pneumocystis carinii (pc), Toxoplasma gondii (tg), Mycobacterium avium (ma), and rat liver (rl). A novel, simple, and feasible methodology was developed for the synthesis of the titled compounds. Amongst these, compound 8 6-phenyl-2-(2-(1-(thiophen-2-yl) ethylidene)hydrazinyl) pyrimidin-4(3H)-one exhibited 17.74 ,M activity against pcDHFR. J. Heterocyclic Chem., (2010). [source]


MgBr2 -mediated opening of 2,3-three membered heterocyclic amines

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
Giuliana Righi
Regio- and stereo-controlled opening of 2,3-epoxy amines and 2,3-aziridine amines by the commercially available MgBr2 is described. As reported, this new method could represent a general and useful approach for the preparation of promising intermediates. Moreover, in particular cases, the reaction evolves toward an interesting oxazolidin-2-one structure. J. Heterocyclic Chem., (2010). [source]


A convenient racemic synthesis of two isomeric tetrahydropyridyl alkaloids: Isoanatabine and anatabine

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
Anne Rouchaud
Anatabine is a major alkaloid in Nicotiana tabacum and its isomer, isoanatabine, was recently found in a marine worm. Reduction of 1-methylpyridinium iodide with sodium borohydride gave 1-methyl-3-piperideine, which was transformed with hydrogen peroxide into the N -oxide. Reaction of the N -oxide successively with trifluoroacetic anhydride and potassium cyanide gave 2-cyano-1-methyl-3-piperideine. Its reaction with 3-pyridylmagnesium chloride gave (▒)- N- methyl-isoanatabine. This was transformed with m -chloroperbenzoic acid into the N -oxide which was N -demethylated with iron(II) sulfate, giving (▒)-isoanatabine. The successive applications of literature procedures for the N -demethylation by decomposition of N -oxide contributed to the knowledge of the mechanism of this oxidative rearrangement. On the other hand, the reduction of 1-methylpyridinium iodide with sodium borohydride and with potassium cyanide present since the start of the reaction in a two layer ether-water system, gave 2-cyano-1-methyl-4-piperideine. This was transformed into (▒)-anatabine by the same sequence of reactions used for the synthesis of (▒)-isoanatabine. J. Heterocyclic Chem., (2010). [source]


Novel tetracyclic imidazole derivatives: Synthesis, dynamic NMR study, and anti-inflammatory evaluation

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
Renata Rup
A series of tetracyclic imidazole derivatives 9a,9v and 10a,10h are prepared by multistep route starting from the known tricyclic diketones 2a,2d. Intermediary dibenzooxepin[4,5- d]imidazoles (3a, 3c) and dibenzothiepin[4,5- d]imidazoles (3b, 3d) are N -protected to 4e, 4f and to the isomeric compounds 5a, 5b and 6a, 6b. The isomeric compounds 5 and 6 are separated. Compounds 4, 5, and 6 are formylated at C(2) to afford 7a,7j. In the last steps, aldehyde group is reduced, then alkylated to the two sets of isomeric ,-dimethylaminoalkyl derivatives 9a,9v. N -deprotection of 9i,9v led to the compounds 10a,10h. Assignment of the syn/anti structure to 5a and 6a was supported by 1D selective ROESY NMR spectra, whereas conformational mobility for the selected representatives 8a and 8b is studied by dynamic NMR. Activation energies (energy barriers for interconversion) are determined to be ,11.5 and 16.2 kcal/mol, respectively. A series of derivatives 9 and 10 were tested in vitro for their anti-inflammatory activity. J. Heterocyclic Chem., (2010). [source]


Quinolone analogues 10: Synthesis of antimalarial quinolones having pyridyl moiety in N1-side chain

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
Yoshihisa Kurasawa
Novel 4-quinolone-3-carboxylates 6,7 and 4-quinolone-3-carboxylic acids 8,11 were synthesized from 4-hydroxyquinoline-3-carboxylates. Ethyl 1-[1-ethoxycarbonyl-2-(4-pyridyl)vinyl]-6-fluoro-4-oxoquinoline-3-carboxylate 7a was found to show antimalarial activity from the screening data. J. Heterocyclic Chem., (2010). [source]


Synthesis and bio-activity of alkyl/aryl [2-(1,2,4,5-tetrahydro-3-sulfanylene/selenylene naphtha[1,8][1,5,3]diazaphosphocin- 3-yl)methyl amino acid esters]

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
S. Subba Reddy
Synthesis of alkyl/aryl [2-(1,2,4,5-tetrahydro-3-sulfanylene/selenylene naphtha[1,8- f,g][1,5,3]diazaphosphocin-3-yl) methyl amino acid esters] (6,15) was accomplished in three steps. 1, 8-diamino naphthalene (2) was reacted with tris (bromomethyl) phosphine (1) in the presence of triethylamine in dry tetrahydrofuran (THF) under N2 atmosphere to form a PIII intermediate (3). It was converted to the corresponding sulfide (4) and selenide (5) by reacting with sulfur and selenium, respectively. The intermediates 4 and 5 were further reacted with amino acid esters to obtain the title compounds (6,15). The structures of the title compounds were established by elemental analysis and spectral data (IR, 1H, 13C, 31P NMR, and FAB mass). The antimicrobial activity of these compounds was evaluated and they exhibited significant activity. J. Heterocyclic Chem., (2010). [source]


Bis-8-hydroxyquinoline and bis-8-hydroxyquinaldine N -substituted amines: A single methyl group structural difference between the two heterocycles, which modulates the antiproliferative effects

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2010
SÚbastien Madonna
The synthesis of a series of bis-8-hydroxyquinoline- and bis-8-hydroxyquinaldine-substituted N -benzyl or thiophenyl amines and their corresponding bis-8-hydroxyquinoline is reported. In vitro growth inhibitory effects of both series have been evaluated. It has been observed that analogs from the bis-8-hydroxyquinoline series exert nanomolar range activity, whereas the antiproliferative activity of the corresponding analogs from the bis-8-hydroxyquinaldine series was found to be drastically lower. Molecular docking and chemical,physical properties account for these observed growth inhibitory differences between the two series of analogs, which differ only by the presence of a methyl group at the 2 position of the heterocyclic ring. J. Heterocyclic Chem., (2010). [source]


On the purity of 2-[ortho -anilinyl]-1,3-benzoxazole derived from 2H -3,1-benzoxazine-2,4(1H)dione (isatoic anhydride) [1,2],

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 2010
Karen M. Button
The Lewis acid catalyzed synthesis and chromatographic purification of isatoic anhydride-derived 2-(2,-anilinyl)-1,3-benzoxazole (2) can result in the co-isolation of 2 and a light pink colored impurity (<5%). This latter species has been identified (NMR, single crystal X-ray diffraction, mp) as 2,-hydroxy-2-aminobenzanilide (3), which represents a predictable intermediate in the formation of 2. Compound 3 crystallizes in an orthorhombic crystal system of space group P212121 with four molecules in the unit cell (, = , = , = 90░; a = 6.715 (2) ┼, b = 12.100 (4) ┼, c = 13.321 (4) ┼; V = 1082.2 (6) ┼3). Pure 2 is characterized as a colorless, high-melting solid; unlike the dark colored oil that is isolated if 2 contains traces of 3. J. Heterocyclic Chem., (2010). [source]


A novel three-component one-pot reaction involving ,-naphthol, aldehydes, and urea promoted by TMSCl/NaI

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 2010
Gowravaram Sabitha
Amidoalkyl naphthol derivatives have been synthesized in good yields in a one-pot condensation of ,-naphthol, aromatic aldehydes and urea in presence of TMSCl/NaI at room temperature. Ring closure of amidoalkyl naphthol derivatives occurred at 140░C to afford 1,2-dihydro-1-arylnaphtho[1,2-e] [1,3]oxazin-3-one derivatives. J. Heterocyclic Chem., (2010). [source]