Search results for "Pyrrole"

A Facile Synthesis of Deaza-Analogues of the Bisindole Marine Alkaloid Topsentin

2013

A series of substituted ethyl 1-[(tert-butoxycarbonyl)amino]-2-methyl-5- (1-methyl-1H-indol-3-yl)-4-[(1-methyl-1H-indol-3-yl)carbonyl]-1H-pyrrole-3-carboxylates were prepared in excellent yields (82-98%) by one-pot reactions between β-dicarbonyl compounds 12a-e and 1,2-diaza-1,3-diene (DD) 13. Derivatives 10a,c-e, deazaanalogues of the bis-indole alkaloid topsentin, screened by the National Cancer Institute (Bethesda, MD, USA) in the in vitro one dose primary anticancer assay against a panel of about 60 human tumor cell lines, showed no significant activity, with the exception of compound 9e, which showed moderate activity against the HOP-92 cell line of the non small cell lung cancer sub-p…

ChemInform Abstract: Pyrroles and Indolizidines from Deprotonated α-(Alkylideneamino)nitriles.

2011

Lead optimization through VLAK protocol: New annelated pyrrolo-pyrimidine derivatives as antitumor agents

2012

Abstract The chemometric protocol VLAK was applied to predict improvement of the biological activity of pyrrolo-pyrimidine derivatives as anticancer agents, by using the NCI ACAM Database as depository of antitumor drugs with a known mechanism of action. Among the selected compounds two of these showed a good increase in the antitumor activity. These new pyrrolo-pyrimidine compounds were demonstrated effective against the full panels of NCI DTP tumour human cell lines. The derivative 8-[3-(piperidino)propyl]-4,10-dimethyl-9-phenyl-6-(methylsulfanyl)-3,4-dihydropyrimido[1,2-c]pyrrolo[3,2-e]pyrimidin-2(8H)-one reveled efficacious against the leukemia subpanel, in particular the RPMI cell line…

Effect of Peripheral Substitution and Extended Conjugation on the Redox Potentials of Nickel Porphycenes

1996

Eight different nickel porphycenes bearing substituents on the pyrrole β and/or ethylenic carbon positions of the macrocycle were investigated as to their redox properties in benzonitrile containin...

Binding of ion pairs and neutral guests by aryl-extended meso‑p-hydroxyphenyl calix[4]pyrrole : The interplay between three binding sites

2023

An aryl-extended calix[4]pyrrole with four meso‑p-hydroxyphenyl substituents was investigated as a host for chloride, acetate, and benzoate anions. Crystal structures of pyridinium and imidazolium chloride complexes were obtained in which chloride ions are hydrogen bonded exo-cavity to the upper rim hydroxyl groups, and the aromatic cations are bound to the shallow cavity of the host. Furthermore, the calix[4]pyrrole formed a hydrogen bonded dimeric capsule templated by inclusion of adiponitrile guest in the endo-cavity binding site. NMR titrations revealed the preference of the OH groups of the host to bind anionic guests in solution. Benzoate anion had the highest binding constant (4 700 …

Polypyrrole–palladium nanoparticles composite as efficient catalyst for Suzuki–Miyaura coupling

2012

International audience; Synthesis of a new hybrid material (Pd/PPy) composed of polypyrrole globules with uniformly incorporated Pd nanoparticles via direct redox reaction between pyrrole and Pd(NH3)(4)Cl-2 in water has been recently reported (V.A. Zinovyeva, M.A.Vorotyntsev, I. Bezverkhyy, D. Chaumont, J.-C. Hierso, Adv. Funct. Mater. 21 (2011) 1064-1075). In the actual study, this procedure has been extended to synthesize a series of Pd/PPy powders with variable palladium content and morphological parameters. Depending on the monomer-to-oxidant ratio in reaction mixture, average diameters of Pd and PPy particles may change in the ranges of 1.25-1.45 and 27-62 nm, respectively, the Pd conc…

Polycondensed nitrogen heterocycles. Part 23. Pyrrolo[3,2-c]cinnolines by a japp-klingemann type reaction

1990

Pyrrolo[3,2-c]cinnoline derivatives were obtained by an unusual Japp-Klingemann reaction involving an intramolecular azadehalogenation on the pyrrole nucleus. Such an azadehalogenation represents the first example of Japp-Klingemann reaction in which the extrusion of positive chlorine ion is verified.

LANGMUIR-SCHAEFER FILMS OF A NEW CALIX[4]PYRROLE-BASED MACROCYCLE EXHIBITING INDUCED CHIRALITY UPON DIFFERENTIATED BINDING WITH CHIRAL ALCOHOL VAPOURS

2004

Synthesis and characterization of lithocholic acid derived dipyrromethanes: precursors for pyrrole-steroidal macrocycles

2004

Abstract Three steroidal dipyrromethanes, 3,3,24,24-tetrakis(pyrrol-2-yl)-5β-cholane 1 , 3,3-bis(pyrrol-2-yl)-5β-cholan-24-oic acid 2 , and methyl 3,3-bis(pyrrol-2-yl)-5β-cholan-24-oate 3 , have been prepared from 3α-hydroxy-5β-cholan-24-oic acid (lithocholic acid) 4 in good overall yields. The structures of 1 – 3 have been fully characterized by 1 H, 13 C, PFG DQF 1 H– 1 H COSY, 1 H– 1 H ROESY, 13 C DEPT-135, PFG 1 H– 13 C HMQC, PFG 1 H– 13 C HMBC, and PFG 1 H– 15 N HMBC NMR spectra. Their molecular weights and compositions have been determined by ESI-TOF and EI mass spectra, and elemental analyses. The energetically optimised geometry and isotropic 13 C NMR chemical shifts of 3,3,24,24-te…

Nitropyrroles, Diels-Alder reactions assisted by microwave irradiation and solvent effect. An experimental and theoretical study

2017

The behaviors of N-tosylnitropyrroles acting as electrophilic dienophiles in polar Diels-Alder reactions joint to different dienes of increeased nucleophilicity are analyzed. The reactions were developed under microwave irradiation using toluene or protic ionic liquids (PILs) as solvents and in free solvent conditions. In all the cases explored we observed good yields in short reaction times. For these reactions, the free solvent condition and the use of protic ionic liquids as solvents offer similar results. However, the free solvent conditions favor environmental sustainability. The role of PILs in these polar Diels-Alder reactions has been theoretically studied within the Molecular Elect…