Synthesis of 4-aryl substituted 3,4-dihydropyrimidinones using silica-chloride under solvent free conditions

This paper describes an improved procedure for the efficient and facile synthesis of 4-aryl substituted 3, 4-dihydropyrimidinones under mild reaction conditions with excellent yields using inexpensive silica chloride under solvent free conditions.     

New tetrazoloquinolinyl methoxyphenyl-4-thiazolidinones: synthesis and antihyperglycemic evaluation

Research on Chemical Intermediates - We report synthesis and in vivo antihyperglycemic evaluation of new 3-substituted...     

Design,synthesis, in silico and biological evaluation of novel 2-(4-(4-substituted piperazin-1-yl)benzylidene)hydrazine carboxamides

A series of novel 2-(4-(4-substituted piperazin-1-yl)benzylidene)hydrazinecarboxamide derivatives has been successfully designed and synthesized to evaluate their potential as carbonic anhydrase (CA) inhibitors. The inhibitory potential of synthesized compounds against human CAI and CAII was evaluated. Compounds 3a–n exhibited \(\hbox {IC}_{50}\) values between \(1.89{-}415.1\,\upmu \hbox {M}\) against CAI and \(0.62{-}66.9\,\upmu \hbox {M}\) against CAII. Compound 3g was the most active inhibitor, with an \(\hbox {IC}_{50}\) value of \(0.62\,\upmu \hbox {M}\) against CAII. Molecular docking studies of compound 3g with CAII showed this compound fits nicely in the active site of CAII and it interacts with the zinc ion (\(\hbox {Zn}^{2+}\)) along with three histidine residues in the active site. Molecular dynamics simulation studies of compound 3g complexed with CAII also showed essential interactions which were maintained up to 40 ns of simulation. In vivo sub-acute toxicity study using 3g (300 mg/kg) was found non-toxic in adult Wistar rats.     

Mechanoluminescence by impulsive deformation of γ-irradiated Er-doped CaF2 crystals

An impulsive technique has been used for mechanoluminescence (ML) measurements in γ-irradiated Er doped CaF₂ crystals. When the ML is excited impulsively by the impact of moving piston on to γ-irradiated CaF₂:Er crystals, two peaks are observed in ML intensity with time and it is seen that the peak intensities of first and second peaks (I_m1 and I_m2) increase with increasing impact velocity. However the time corresponding to first and second peaks (t_m1 and t_m2) shifts towards shorter time values with increasing impact velocity. It is also seen that the total ML intensity I_Total initially increases with the impact velocity and then it attains a saturation value for higher values of the impact velocity. We have presented a theoretical explanation for the observed results.     

Molecular interactions and structural effects on mixing pentanol in polyethylene glycol diacrylate and polyethylene glycol dimethacrylate

To understand the intermolecular interactions in binary mixtures of pentanol with polyethylene glycol diacrylate and polyethylene glycol dimethacrylate respectively, absolute viscosity and refractive index have been measured over the whole composition range, at 298.15 K, 303.15 K and 313.15 K, under atmospheric pressure. Molar refraction and interaction parameter have been calculated. The experimental data have been used to evaluate deviation in viscosity, deviation in refractive index and excess Gibb's free energy of activation for viscous flow, and the results have been fitted to Redlich-Kister polynomial equation.     

Trace formula for level density of a spherical billiard

A trace formula for the oscillating part of the level density for a spherical billiard has been obtained in spherical polar coordinates. The Jacobian of stability and the length of the orbits are obtained from the classical mechanics of the problem. The same formula is applicable to both the planar and the diametric orbits. Numerical results have been obtained with this formula and compared with the results from exact quantum theory, EBK quantization, and Balian and Bloch.     

Reaction of 4-styryl-1,2,3-benzoxathiazine 2,2-dioxides with diazomethane: Synthesis of a novel heterocyclic system

A new class of heterocyclic system, 3a-f , has been synthesized by reacting diazomethane with 4-styryl-1,2,3-benzoxathiazine 2,2-dioxides 1a-f . Diazomethane adds to the > C = S group of these compounds.     

Inorganic particulates in removal of toxic heavy metal ions

The removal behavior of amorphous aluminum hydroxide for Hg(II) ions from aqueous solutions was investigated by employing a radiotracer technique at micro down to trace level concentrations. The batch type experiments were performed to obtain various physico-chemical parameters, viz., effect of sorptive concentration, temperature and pH. It was observed that the increase in sorptive concentration (from 1·10⁻⁸ to 1·10⁻² mol·dm⁻³), temperature (from 303 to 333K) and pH (from 3.4 to 10.3) apparently favored the uptake of Hg(II) by this solid. Similarly, the presence of anions (six fold) viz., oxalate, phosphate, glycine and EDTA also enhanced the uptake behavior of aluminum hydroxide for Hg(II). Whereas, the added cations viz., Na⁺, K⁺, Ba²⁺, Sr²⁺, Mg²⁺, Cd²⁺ and Fe³⁺ more or less suppressed the removal behavior of the adsorbent. Further, the adsorption process followed the classical Freundlich adsorption isotherm and deductions of various thermodynamic data revealed that the uptake of Hg(II) on aluminum hydroxide followed the ion-exchange type mechanism and thermodynamically it was found to be endothermic in nature. Part IX: Rapid and efficient removal of Hg(II) by hydrous manganese and tin oxides, J. Coll. Interf. Sci., 279 (2004) 61.     

Thionation of phosphoramidodichloridates and phosphoramidate diesters using phosphorus pentasulfide and hexamethyldisiloxane under microwave irradiation. Part 1

A new, mild, efficient, and solvent-free microwave promoted synthesis of thiophosphoramidodichloridates and thiophosphoramidate diesters is described. The thionation reaction was accelerated with microwave irradiation using the combination of P₄S₁₀ and HMDO. The conversion of PO to PS by this method gave the desired product in higher yields and shorter reaction times as compared to conventional methods.     

Selenoether macrocyclic chemistry--syntheses and properties of new potentially tridentate and hexadentate Se/O-donor macrocycles

Treatment of O(CH2CH2SeCN)2 with Na in NH3(l), followed by dropwise addition of a thf solution of o-C6H4(CH2Br)2 at -40 degrees C leads to formation of three mixed Se/O-donor macrocycles which are separable by column chromatography, the [1 + 1] species L1, the [2 + 2] ring L2 and the [3 + 3] ring L3, of which L2 is by far the major species. Using the same starting materials, but in a high dilution cyclisation at room temperature with NaBH4 in thf/EtOH gives exclusively the [1 + 1] ring, L1. The saturated ring Se/O-donor macrocycles, L4 and L5 are obtained by simultaneous dropwise addition of solutions of O(CH2CH2SeCN)2 and Br(CH2)3Br to NaBH4 suspended in thf/EtOH. The small tridentate Se2O-donor ring, L4, is again the dominant product under these conditions (71%), although the more flexible precursors in this reaction also give rise to the larger Se4O2-donor ring, L5, as a by-product in 8% yield. These compounds are readily separated and purified by column chromatography (ethyl acetate:hexane, 1:19). The new macrocycles have been characterised by 1H, (13)C{1H} and (77)Se{1H} NMR spectroscopy and mass spectrometry, together with crystal structures of L1 and L2. Complexes of L1 and L2 with late transition metals (Pd(II), Pt(II), Cu(I) and Ag(I)) are also described.