A tautomeric equilibrium exists for quinoline-2-thiol and quinoline-2(1H)-thione. Quantum mechanical calculations predict the thione is the major tautomer and this is confirmed by the absorption spectra. The utility of quinolone-2-thiol/quinoline-2(1H)-thione as a chromophore for developing fluorescent sensors is explored. No fluorescence is observed when excited at absorption maxima, however a fluorescence increase is observed when exposed to HNO, a molecule of import as a cardiovascular therapeutic. Alkylated quinoline-2-thiol derivatives are found to be fluorescent and show a reduction in fluorescence when exposed to metals and changes in pH.

The condensation of several aromatic/heteroaromatic aldehydes with 2-aminothiophenol under melt reaction conditions afforded 2-arylbenzothiazoles under solvent-free conditions. The major advantages of the present method are high yields, short reaction times, and eco-friendly conditions.

An ionic liquid 1-Butyl-3-methylimidazoliumchloride[BMIm]Cl/sodium hydroxide system, was employed as a catalyst for the fast and one-pot crossed aldol-condensation of various aromatic aldehydes and cyclic ketones, to produce a variety of substituted ?,? & apos; -bis(benzylidene)-cycloalkanones under neat conditions. This process is simple, efficient and environmentally benign and proceeds in high yield and short reaction times. The ionic liquid can be recycled for subsequent reactions without any appreciable loss of efficiency.

An efficient and simple synthesis of some 2-amino-3-cyano-4H-pyran derivatives was developed by the one-pot and three-component reaction of aldehydes, ethyl acetoacetate, and malononitrile in the presence of ammonia as catalyst at room temperature. The reaction is rapid and clean, and gives the products in high yields.

In this article, an efficient, environmentally benign, solvent-free synthesis of diethyl-2,6-dimethyl-4-(1-phenyl-3-aryl-1H-pyrazol-4-yl)-1,4-dihydropyridine-3,5-dicarboxylates and their simple oxidative aromatization in presence of selected hypervalent iodine (III) reagents under solvent-free condition at room temperature is demonstrated. All reactions were carried out by grinding the reactant pyrazole substituted Hantzch-1,4-dihydropyridines and hypervalent iodine (III) reagent in a mortar with pestle. [Hydroxy(tosyloxy)iodo]benzene act as an more efficient oxidizing reagent in comparison to phenyliodine bistrifluoroacetate and iodobenzene diacetate in terms of reaction time and yields. The advantages of present protocol are the environment friendly, short reaction time, mild reaction conditions, and high yields of the products.

The predominant tautomeric forms of N1–H, N2–H of 5-(2,6-dimethyl- and 5-(2,6-diisopropylphenoxy)-(1H)-tetrazoles were analyzed at B3LYP method using 6-311G(d,p) basis set in the gas phase. The N1–H form of tetrazoles was found to be more stable than N2–H form in both solid and gas phases. Crystal structures of both tetrazoles show an intermolecular H-bond between N1-H and N4 atom of other tetrazole space. The hydrogen bonds between each tautomer of tetrazoles were evaluated at B3LYP/6-311G(d,p) level. The geometrical parameters and spectral data of tetrazoles and their variation were studied in both solid and gas phases.

A simple and efficient procedure for the synthesis of 3, 4-dihydropyrimidin-2(1H)-ones under solvent-free condition using non-toxic and mild acid mesoporous SBA-15 nanoparticles as a catalyst has been investigated. This method has the advantages of the excellent yield, short reaction time, environmentally friendly conditions and simple experimental procedure.

The novel ?-phosphorus labile ylide of 1-(p-tolyl)-2-(tri-p-tolylphosphoranylidene)ethanone (PTTPPY) is prepared by the reaction of 2-bromo-1-(p-tolyl)ethanone with tri-p-tolylphosphine in chloroform as solvent. The complexes of the type [HgX2(p-tolyl)3PCHCOC6H4CH3)] (X = Cl, Br and I) are prepared by the reaction of title ylide with mercury(II) halides in good yields, using methanol as solvent. The final products were characterized by IR, 1H, 13C, 31P NMR spectroscopic methods and microanalysis.

Kinetics of the oxidation of primary aliphatic alcohols has been carried out using phase transferred monochromate in benzene. Tetrabutylammonium bromide (TBAB) and tetrabutylphosphonium bromide (TBPB) are used as phase transfer catalysts (PT catalyst). The reaction shows first order dependence on both [alcohol] and [monochromate ion]. The oxidation leads to the formation of corresponding aldehyde and no traces of carboxylic acid has been detected. The reaction mixture failed to induce the polymerization of added acrylonitrile which rules out the presence radical intermediates in the reaction. Various thermodynamic parameters have been evaluated and a suitable mechanism has been proposed.

In this work, acidity constants protonated form of 4.4 & apos; -bis astilbene-2,2 & apos; -disulfonic-disodium salts (TRIAZ) have been determined spectrophotometrically and spectrofluorimetrically at 25?C and ionic strength of 0.1M KNO3. A program based on MCR-ALS applied for determination of acidity constants. The results show that the peak values of dye are influenced by the presence of anionic, cationic, and nonionic surfactants. The effects of sodium dodecyl sulfate (SDS), Triton X-100 (TX-100) and cetyl trimethyl ammonium bromide (CTAB) as a surface-active agent on the acidic and basic forms, and the spectral properties of dye were studied. Also, we determined the critical micelle concentration (CMC) for these surfactants by spectrophotometric and spectrofluorimetric triazine dye probes. In addition, by using of evolving factor analysis (EFA) and multivariate curve resolution alternative least squares (MCR-ALS) methods, acidity constants were acquired.