Synthesis and properties of bi- and tricyclic 1,3-thiazoline/thiazolidine assemblies linked by an exocyclic С=С double bond

Chemistry of Heterocyclic Compounds - This review provides a generalized and systematized analysis of literature data from the last 15 years regarding the methods of synthesis and properties of bi-...     

Synthesis,structure and antitumor activity of the binuclear tetranitrosyl iron complex with 2-mercaptobenzthiazole – the nitric oxide donor (NO)

Single-crystals of binuclear neutral sulfur-nitrosyl iron complex with 2-mercaptobenzthiazole ligand [Fe₂(С₇н₄NS₂)₂(NO)₄] (BTz) have been obtained. From X-ray data, BTz has a centrosymmetric dimeric structure, with the iron atoms being linked through the µ-N-C-S bridge. As follows from mass-spectra of the BTz gas phase, the complex is stable in the crystalline state under normal conditions (ambient temperature and standard humidity) and releases nitric oxide upon heating. Using amperometry, kinetics of NO release by BTz in 1% dimethyl sulfoxide aqueous solution has been studied: release of NO was shown to occur immediately upon dissolution in protic media. BTz inhibited growth of K562 leukemia and SKOV₃ ovarian carcinoma cells in vitro and induced apoptosis via activation caspases 3 and 7.     

Coherence resonance in an excitable potential well

The excitable behaviour is considered as motion of a particle in a potential field in the presence of dissipation. The dynamics of the oscillator proposed in the present paper corresponds to the excitable behaviour in a potential well under condition of positive dissipation. Type-II excitability of the offered system results from intrinsic peculiarities of the potential well, whose shape depends on a system state. Concept of an excitable potential well is introduced. The effect of coherence resonance and self-oscillation excitation in a state-dependent potential well under condition of positive dissipation are explored in numerical experiments.     

Facile and efficient aerobic one-pot synthesis of benzimidazoles using Ce(NO3)3·6H2O as promoter

A series of 2-substituted benzimidazoles was synthesized under aerobic conditions, by simply heating 1,2-diaminobenzene and aldehydes in DMF at 80 °C, employing Ce(NO₃)₃·6H₂O as promoter and atmospheric air as an efficient oxidant. The procedure afforded the products from good to excellent yields. Furthermore, this new economic and eco-friendly protocol avoids the use of toxic metal catalysts, as well as additional bases and oxidants.     

Acetone promoted 1,4-migration of an alkoxycarbonyl group on a syn-1,2-diamine

A 2-protected cis-amino mitosene undergoes an irreversible acetone promoted isomerization and converts to the 1-isomer. Kinetic studies and DFT calculations of the reaction are reported. An organocatalytic mechanism is proposed, involving a covalent intermediate formed by reaction of the mitosene and acetone.     

Poly(4-amino-2,1,3-benzothiadiazole) films: preparation,characterization and applications

The electrochemical preparation of novel poly(4-amino-2,1,3-benzothiadiazole) films on a platinum surface in sulfuric aqueous medium by cyclic voltammetry is described. The resulting polymeric electrodes were characterized by FT Raman spectroscopy, scanning electron microscopy and potentiometry. Spectroscopic measurements confirmed the participation of the amino group and sulfur atom in the process that forms the granular structure of poly(ABTD). Potentiometric results showed the response of the poly(ABTD) film towards divalent cations such as Zn²⁺ and Cd²⁺ in the concentration range from 10^?7 up to 10^?2 mol L^?1. A cooperative combination of the cation-sensitive poly(ABTD) electrodes in an array with pH- and anion-sensitive electrodes was able to recognize different Czech beers.     

Synthesis of 5-(5-amino-1H-pyrazol-1-yl)-1,2,3-thiadiazole-4-carboxylic acid ethyl esters and their cyclization into pyrazolo[1,5-a][1,2,3]thiadiazolo[4,5-e]pyrimidin-4(5H)-ones

Chemistry of Heterocyclic Compounds - A method for the synthesis of novel 1H-pyrazol-1-yl-1,2,3-thiadiazole derivatives has been proposed and their intramolecular cyclization to...