Search results for "Quinoline"
showing 10 items of 391 documents
Mono-aryltin(IV) and mono-benzyltin(IV) complexes with pyridine-2-carboxylic acid and 8-hydroxyquinoline. X-ray structure of p-chloro-phenyl-tris(8-q…
1999
Abstract Complexes RSn(O2CPy)3·2H2O and RSn(Ox)3, (PyCOOH=pyridine-2-carboxylic acid, HOx=8-hydroxyquinoline, R=o- and p-Tolyl, o- and p-ClC6H4=o- and p-ClPh, o-ClC6H4CH2=o-ClBenzyl; besides, R=Ph in RSn(Ox)3) have been synthesized and characterized by elemental analysis and determination of molecular weights in CHCl3 solutions. The structure of p-ClPhSn(Ox)3·2CHCl3 has been determined by X-ray diffractometry. The 7-coordinated tin atom of the monomeric compound is in the center of a pentagonal bipyramid formed by (p-ClPh)C and O and N atoms of the chelating Ox− ligands. The latter type of structure would hold for all complexes according to 119Sn Mossbauer (including the determination of th…
Synthesis of cyclic dipeptide templates, their incorporation into peptides and studies on their conformational and biological properties.
2009
This study investigated the diastereoselective synthesis of three dipeptide templates 1, 2 and 3, which may be regarded as conformationally restricted analogs of H-Gly-Xaa-OH, in which Xaa constitutes an aromatic amino acid. Bond formation between α-C of Gly and the aromatic moiety was achieved by proton-catalyzed intramolecular electrophilic aromatic substitution. The absolute configuration of the dipeptide templates was determined by single-crystal X-ray crystallography or by nuclear Overhauser enhancement measurements. A protective group strategy was elaborated to allow their incorporation into peptide sequences by liquid phase as well as by solid-phase peptide synthesis. The templates w…
On the regioselectivity of the Friedländer reaction leading to huprines: stereospecific acid-promoted isomerization of syn-huprines to their anti-reg…
2001
Abstract Racemic 12-amino-6,7,8,11-tetrahydro-7,11-methanocycloocta[ b ]quinoline derivatives ( syn -huprines) substituted at the 9-position with a methyl or ethyl group, and both enantioenriched forms of the 9-ethyl derivative, obtained by chiral MPLC resolution of the racemic mixture, were readily converted to the corresponding anti -isomers (huprines) by stereospecific acid-promoted (AlCl 3 or triflic acid) isomerization of the endocyclic CC double bond from the 9(10)- to the 8(9)-position. These results support the hypothesis that the hitherto unseen syn -huprines are also formed under the usual acidic Friedlander reaction conditions used to prepare the known huprines, but rearrange in…
Solid State Structures of Amide-Substituted 8-Hydroxyquinoline Derivatives
2000
Abstract The amide substituted 8-hydroxyquinoline derivatives 3 and 4 form, in the solid state, hydrogen bonded polymers. Polymeric 3 adopts a helical conformation while 4 forms a double-stranded ladder-type structure.
Synthesis of Quinoline-Based Anion Receptors and Preliminary Anion Binding Studies with Selected Derivatives
2014
Six quinoline-based anion receptors were designed, prepared, and characterized, among which the crystal structure of an indole derivative was obtained. Selected receptors were tested for the recognition of halide anions in solution and showed some selectivity of chloride over bromide and iodide.
The deprotonative metalation of [1,2,3]triazolo[1,5-a]quinoline. Synthesis of 8-haloquinolin-2-carboxaldehydes
2009
New highly functionalized triazoloquinolines were synthesized by applying polar organometallic methods. Double metalation and functionalization provided 3,9-dihalogenated triazoloquinolines. Ring opening of the triazole with loss of nitrogen has been performed for the first time with 3,9-dihalogenated triazoloquinolines allowing the access toward 8-haloquinolin-2-carboxaldehydes under oxidant-free conditions. This approach demonstrates that the triazole ring can be used as protecting group of 2-quinolinecarboxaldehydes, activating the C9-position for lithiation and functionalization by triazole ring opening. 8-Haloquinoline-2-carbaldehydes become in this way readily available.
Photoinduced and Self‐Activated Nuclease Activity of Copper(II) Complexes with N ‐(Quinolin‐8‐yl)quinolin‐8‐sulfonamide – DNA and Bovine Serum Album…
2016
Two CuII complexes with a new quinoline sulfonamide derivative and phenanthroline (phen), [Cu(QSQ)(phen)]ClO4·0.5H2O (1) and [Cu(QSQ)(phen)(H2O)]ClO4 (2) [HQSQ = N-(quinolin-8-yl)quinolin-8-sulfonamide], have been synthesized and physicochemically characterized. Single-crystal X-ray diffraction studies have revealed a highly distorted trigonal-bipyramidal structure for 1 (τ = 0.68) and an almost perfect trigonal-bipyramidal geometry for 2 (τ = 0.92). DNA binding studies, which were performed by thermal denaturation, viscometry, fluorescence spectroscopy, and cyclic voltammetry, indicated a partial intercalation of 1 with Kapp = 2.45 × 106 M–1. The nuclease activity of 1 was investigated upo…
Highly Luminescent Half-Lantern Cyclometalated Platinum(II) Complex: Synthesis, Structure, Luminescence Studies, and Reactivity.
2012
The half-lantern compound [{Pt(bzq)(μ-C 7H 4NS 2-κN,S)} 2]•Me 2CO (1) was obtained by reaction of equimolar amounts of potassium 2-mercaptobenzothiazolate (KC 7H 4NS 2) and [Pt(bzq)(NCMe) 2]ClO 4. The Pt(II)•••Pt(II) separation in the neutral complex [{Pt(bzq)(μ-C 7H 4NS 2-κN,S)} 2] is 2.910 (2) Å, this being among the shortest observed in half-lantern divalent platinum complexes. Within the complex, the benzo[h]quinoline (bzq) groups lie in close proximity with most C•••C distances being between 3.3 and 3.7 Å, which is indicative of significant π-π interactions. The reaction of 1 with halogens X 2 (X 2 = Cl 2, Br 2, or I 2) proceeds with a two-electron oxidation to give the corresponding d…
Carbonic anhydrase inhibitors
1999
Reaction of 20 aromatic/heterocyclic sulfonamides containing a free amino, imino, hydrazino or hydroxyl group, with 8-quinoline-sulfonyl chloride afforded a series of water-soluble (as hydrochloride or triflate salts) compounds. The new derivatives were assayed as inhibitors of the zinc enzyme carbonic anhydrase (CA), and more precisely of three of its isozymes, CA I, II (cytosolic forms) and IV (membrane-bound form), involved in important physiological processes. Efficient inhibition was observed against all three isozymes, but especially against CA II (in nanomolar range), which is the isozyme known to play a critical role in aqueous humor secretion within the ciliary processes of the eye…
Effective Removal and Mineralization of 8-Hydroxyquinoline-5-sulfonic Acid through a Pressurized Electro-Fenton-like Process with Ni−Cu−Al Layered Do…
2020
Ni−Cu−Al layered double hydroxide (Ni−Cu−Al LDH) was proposed as an electro‐Fenton‐like catalyst for 8‐hydroxyquinoline‐5‐sulfonic acid (8‐HQS) removal in water. The properties of the prepared catalysts were characterized by using X‐ray, SEM and EDAX analyses. The effect of numerous operative parameters on the removal of 8‐HQS and total organic carbon (TOC) was studied. Very high level removal of both 8‐HQS and TOC (87 and 79 %, respectively) were obtained by using a pressurized electro‐Fenton‐like process (PrEFL‐LDH) at P=10 bars, using a Ti/IrO2‐Ta2O5 anode for 6 h. The process presented good performances in a large range of pH (3–10) and gave better removals of 8‐HQS and TOC with respect…