Search results for "Pyrrole"

Structural and spectroscopic characterisation of 2-(2'-hydroxybenzoyl)pyrrole and its O-methyl derivative

2004

Abstract Density functional theory calculations on the tautomeric and conformational equilibria of 2-(2′-hydroxybenzoyl)pyrrole (HBP) and 2-(2′-methoxybenzoyl)pyrrole (MBP) were performed. Moreover, the experimental IR and UV spectra of the same compounds were recorded and compared with the theoretical data. The presence of an intramolecular hydrogen bond in HBP can be related to the biological activities of some of its derivatives.

Extension of the potential intervals of high redox activity and electronic conductivity of polypyrrole films on electrode surface via their electroch…

2021

Abstract Thin polypyrrole films (thickness: about 30 nm) have been deposited at electrode surface via potentiostatic oxidation of dilute (1 mM) pyrrole solution in acetonitrile (AN). It has been shown that their subsequent treatment by means of multi-cycle voltammetry within a broad potential range (up to -2.0 V vs. Ag/Ag+ in AN) leads to their "activation", i.e. to a very strong extension of their redox response region in the negative direction as well as to almost uniform distribution of the redox activity within this potential range. Region of their high conductivity under in situ conditions has also extended significantly. Spectral and electrocatalytic properties of such PPy films befor…

ChemInform Abstract: (4 + 2) Cycloaddition of Indole Derivatives with Bismaleimides: A Route to New Biscarbazoles.

2010

Profile and molecular modeling of 3-(indole-3-yl)-4-(3,4,5-trimethoxyphenyl)-1 H-pyrrole-2,5-dione (1) as a highly selective VEGF-R2/3 inhibitor.

2006

We report on selectivity profiling of 1 in a panel of 20 protein kinases and molecular modeling indicating 1 to be highly active and selective for VEGF-R2/3. Sequence alignment analysis and detailed insights into the ATP binding pockets of targeted protein kinases from the panel result in a unique structural architecture of VEGF-R2 mainly caused by the hydrophobic pocket I, determining the molecular basis for activity and selectivity of 1.

Two-Step Route to Indoles and Analogues from Haloarenes: A Variation on the Fischer Indole Synthesis

2012

In a new variation on the Fischer indole synthesis, readily available haloarenes are converted into a wide range of indoles in just two steps by halogen-magnesium exchange and quenching with di-tert-butyl azodicarboxylate, followed by reaction with aldehydes or ketones under acidic conditions. The protocol, which is readily extended to the preparation of indole isosteres, 4- and 6-azaindoles and thienopyrroles, obviates the need to prepare potentially toxic aryl hydrazines, simultaneously avoiding undesirable anilines such as naphthylamines.

Polycondensed nitrogen heterocycles. Part13. Pyrrolo[3,2-b]indole by intramolecular nucleophilic substitution reaction in the pyrrole series

1984

An intramolecular nucleophilic substitution in the pyrrole series has been generalized. The behaviour of nitro, chlorine, bromine and iodine as leaving groups towards the nucleophilic amino group was observed. An acid catalyzed mechanism has been proposed.

Catalytic Asymmetric Friedel–Crafts Alkylations in Total Synthesis

2009

SYNTHESIS AND PHOTOCHEMIOTHERAPEUTIC ACTIVITY OF THIOPYRANO[2,3-E]INDOL-2-ONES

2004

A series of derivatives of the new ring system thiopyrano[2,3-e]indol-2-one was prepared with the aim of obtaining new photochemotherapeutic drugs. Biological screenings were performed on this new class of photoactivable drugs and a strong antiproliferative effect was observed upon irradiation with UVA light. The compound bearing a methyl substituent at the pyrrole nitrogen resulted as the most interesting showing IC50 in the nanomolar range.

3-[4-(1H-indol-3-yl)-1,3-thiazol-2-yl]-1H-pyrrolo[2,3-b]pyridines, nortopsentin Analogues with antiproliferative activity

2015

A new series of nortopsentin analogues, in which the imidazole ring of the natural product was replaced by thiazole and the indole unit bound to position 2 of the thiazole ring was substituted by a 7-azaindole moiety, was efficiently synthesized. Two of the new nortopsentin analogues showed good antiproliferative effect against the totality of the NCI full panel of human tumor cell lines (~60) having GI50 values ranging from low micromolar to nanomolar level. The mechanism of the antiproliferative effect of these derivatives, investigated on human hepatoma HepG2 cells, was pro-apoptotic, being associated with externalization of plasma membrane phosphatidylserine and mitochondrial dysfunctio…

Elaboration of ammonia gas sensors based on electrodeposited polypyrrole - cobalt phthalocyanine hybrid films

2013

The electrochemical incorporation of a sulfonated cobalt phthalocyanine (sCoPc) in conducting polypyrrole (PPy) was done, in the presence or absence of LiClO4, in order to use the resulting hybrid material for the sensing of ammonia. After electrochemical deposition, the morphological features and structural properties of polypyrrole/phthalocyanine hybrid films were investigated and compared to those of polypyrrole films. A gas sensor consisting in platinum microelectrodes arrays was fabricated using silicon microtechnologies, and the polypyrrole and polypyrrole/phthalocyanine films were electrochemically deposited on the platinum microelectrodes arrays of this gas sensor. When exposed to a…