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Heterocyclic Moiety (heterocyclic + moiety)
Selected AbstractsFunctional modification of poly(vinyl alcohol) through phosphorus containing nitrogen heterocyclic moietiesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008S. Karpagam Abstract Functional modification of poly(vinyl alcohol) (PVA) with phosphorus containing nitrogen heterocyclic has been believed to have extensive thermal and biological applications in the area of polymers. Efforts have been taken for the synthesis of phosphorus-containing N -heterocyclic (5,6 member and fused ring) based PVA. The synthesized compounds were characterized using UV, FTIR, and NMR spectral studies. Thermal studies (DSC-TGA) scans display phosphorus-containing five membered and fused heterocyclic-based PVA has less thermal stability than six-membered compounds. Modified polymers infer to have excellent bacterial response against micro-organisms. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Synthesis of bis-heteroaryl piperazine derivatives as potential reverse transcriptase inhibitorsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2001Jean Guillaumel Vinylogous analogs of non-nucleoside reverse transcriptase inhibitors belonging to the bis-(hetero-aryl)piperazine (BHAP) series were synthesized by coupling a piperazine derivative with (E)-propenoyl derivatives of heterocyclic moieties. [source] Alkylation of azoles: Synthesis of new heterocyclic-based AT1 -non-peptide angiotensin (II) receptor antagonistsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2007Amal Al-Azmi Several novel analogues of Losartan 2 were synthesized as potential non-peptide angiotensin (II) receptor antagonists. In these non-peptide analogues, the tetrazole and the substituted imidazole rings of Losartan 2 were replaced, respectively, by a carboxylic acid function or its methyl ester and substituted triazole, imidazole or benzimidazole moieties. The biphenyl bromide precursor 3 (BPE) used to introduce the linker between the acid/ester function and the heterocyclic moiety was synthesized using Suzuki biphenyl coupling and then incorporated into the target molecule by simple nucleophilic substitution. The fixed N-aryl isomeric forms of several azole and benzimidazole tautomers were successfully separated by HPLC using 50% aqueous acetonitrile as eluent. Intermediate reaction products and final target compounds were fully characterized spectroscopically. [source] Chemical modification of chitosan: synthesis and biological activity of new heterocyclic chitosan derivativesPOLYMER INTERNATIONAL, Issue 2 2008Mohamed EI Badawy Abstract BACKGROUND: Numerous works have been published on the chemical modification of chitosan; this polymer is still being modified, leading to various derivatives with improved properties. In the present study, heterocyclic aldehydes including furan-2-carbaldehyde, 5-methylfuran-2-carbaldehyde, 3-pyridine carboxyaldehyde, benzo[d][1,3]dioxole-5-carbaldehyde and 4-oxo-4H -chromene-3-carbaldehyde were reacted with chitosan by a reductive alkylation reaction to produce for the first time five new N -heterocyclic chitosan derivatives to improve the biological activity of chitosan against the most important economic plant pests including fungi and insects, in particular the cotton leafworm Spodoptera littoralis. RESULTS: The chemical structures of the synthesized compounds were confirmed by 1H NMR spectroscopy and the degree of substitution ranged from 0.30 to 0.43. The fungicidal assessment was investigated in vitro using a mycelia radial growth inhibition technique against soil-borne pathogenic fungi Fusarium oxysporum and Pythium debaryanum and the rice leaf blast Pyricularia grisea. The results showed that N -[(5-methylfuran-2-yl)methyl] chitosan was the most active against P. grisea with an EC50 value of 0.919 mg mL,1 while N -(benzo[d][1,3]dioxol-5-ylmethyl) chitosan and N -(methyl-4H -chromen-4-one) chitosan exhibited the most potent fungicidal activity against P. debaryanum and F. oxysporum. An insecticidal bioassay against the larvae of S. littoralis showed that N -(methyl-4H -chromen-4-one) chitosan exhibited a significant growth inhibition and antifeedant activity among the synthesized compounds. CONCLUSION: The chemical modification of chitosan molecule with a heterocyclic moiety led to an enhancement in the biological activity against the plant pathogenic fungi F. oxysporum, P. debaryanum and P. grisea and the cotton leafworm insect S. littoralis. Copyright © 2007 Society of Chemical Industry [source] 2-Amino-8-(2-deoxy-2-fluoro-,- d -arabinofuranosyl)imidazo[1,2- a][1,3,5]triazin-4(8H)-one monohydrate, a 2,-deoxyguanosine analogue with an altered Watson,Crick recognition siteACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010Dawei Jiang The title compound, C10H12FN5O4·H2O, shows an anti glycosyl orientation [, = ,123.1,(2)°]. The 2-deoxy-2-fluoroarabinofuranosyl moiety exhibits a major C2,- endo sugar puckering (S -type, C2,- endo,C1,- exo, 2T1), with P = 156.9,(2)° and ,m = 36.8,(1)°, while in solution a predominantly N conformation of the sugar moiety is observed. The conformation around the exocyclic C4,,C5, bond is ,sc (trans, gauche), with , = ,78.3,(2)°. Both nucleoside and solvent molecules participate in the formation of a three-dimensional hydrogen-bonding pattern via intermolecular N,H...O and O,H...O hydrogen bonds; the N atoms of the heterocyclic moiety and the F substituent do not take part in hydrogen bonding. [source] Synthesis and HPLC enantioseparation of the cyclopropane analogue of valine (c3Val)CHIRALITY, Issue 1 2005Ana I. Jiménez Abstract A new and efficient method is presented for the preparation of the N -Boc-protected cyclopropane analogue of valine, 1-(N-tert -butoxycarbonyl)amino-2,2-dimethylcyclopropanecarboxylic acid, both in racemic and enantiomerically pure forms. Cyclopropanation of the exocyclic double bond of 2-phenyl-4-isopropylidene-5(4H)-oxazolone with diazomethane followed by elaboration of the heterocyclic moiety provided multigram quantities of the racemic target compound. Subsequent HPLC resolution of a racemic precursor on a noncommercial chiral stationary phase has given access to enantiomerically pure products. Almost 1.5 g of the first-eluted enantiomer and 1.0 g of the second-eluted enantiomer have been isolated in optically pure form using a 150 × 20 mm ID column containing mixed 10-undecenoate/3,5-dimethylphenylcarbamate of cellulose covalently bonded to allylsilica gel with a mixture of hexanes/tert -butyl methyl ether/ethyl acetate as the mobile phase. Chirality 17:22,29, 2005. ©2004 Wiley-Liss, Inc. [source] Synthesis, spectral properties and application of novel disazo disperse dyes derived from polyester wasteCOLORATION TECHNOLOGY, Issue 2 2010V S Palekar Terephthalic dihydrazide was obtained through aminolytic depolymerisation of polyester bottle waste by using hydrazine hydrate. It was further reacted with 4-aminobenzoic acid in the presence of polyphosphoric acid to obtain a cyclic compound, 4,4,-[5,5,-(1,4)-phenylene)bis(1,3,4-oxadiazole-5,2-diyl)dianiline, having a heterocyclic moiety. Diazotisation of this compound followed by coupling with various N,N -disubstituted anilines afford a series of novel disazo disperse dyes. The structures of these synthesised dyes were confirmed by elemental analysis and Fourier Transform,infrared, proton nuclear magnetic resonance and mass spectroscopy. Ultraviolet,visible spectra of these azo dyes in different polar solvents showed considerable variation in the wavelength of maximum absorbance (,max). Application of these dyes on polyester and nylon fabrics using high-temperature dyeing methods gave brilliant yellowish red hues with fair to moderate light fastness and very good to excellent wash fastness and sublimation fastness. [source] | |||||||||||||