Synthesis of a New Calix[4]Arene and Its Application in Construction of a Highly Selective Silver Ion-Selective Membrane Electrode

A PVC membrane sensor for Ag (I) ions has been prepared. The membrane has 5, 11, 17, 23-tetra-tert-butyl-25-(3-N, N-diethyldithio carbamoylpropoxy)-26,27,28-tris-propoxy calix[4]arene (CAD) as a carrier. It was found that the sensor exhibits a Nernstian response for Ag+ ions over a wide concentration range (10−2–10−6 M). Additionally, it illustrates a fast response time (about 5 seconds), and it can be used for at least 2 months without any considerable divergence in potentials. The nature of the plasticizer, the additive, the concentration of internal solutions in the electrodes, and the composition of the membrane were investigated. Furthermore, the suggested membrane electrode revealed good selectivities for Ag+ over a variety of other metal cations, and it could be used in the pH range of 3.0–7.0. Eventually, it was successfully applied as an indicator electrode for the potentiometric titration of Ag+ ion with NaCl.

Accelerations in the Lactonization of Trimethyl Lock Systems Are due to Proximity Orientation and not to Strain Effects

DFT at B3LYP/6-31G(d,p) and HF at 6-31G and AM1 semiempirical calculations of thermodynamc and kinetic parameters for the trimethyl lock system (an important enzyme model) indicate that the remarkable enhancement in the lactonizations is largely the result of a proximity orientation as opposed to the currently advanced strain effect.

Synthesis of Benzo[b]fluorenone Nuclei of Stealthins

Two routes, one based on a Michael-initiated aldol condensation and the other on an intramoleculer carbonyl-ene reaction, have been found to be feasible for an entry to benzo[b]fluorenones. Reaction of 4,9-dimethoxybenz[f]indenone with nitromethane in the presence of DBU gave the corresponding Michael adduct, which afforded 2-methyl-5,10-dimethoxybenzo[b]fluorenone on reaction with methacrolein under a variety of basic conditions. Similarly, 2-methallyl-4,9-dimethoxybenz[f]indenone reacted with nitromethane to give the corresponding Michael adduct, Nef reaction of which furnished 3-formyl-2-methyl-4,9-dimethoxybenz[f]indanone. This underwent ene-cyclization under the influence of SnCl4. 5H2O, and yielded 2-methyl-5,10-dimethoxybenzo[b]fluorenone.

An Efficient Preparation, Spectroscopic Properties, and Crystal Structure of 1,1-Bis(4-[2-(dimethylamino)ethoxy]phenyl)-2-(3-guaiazulenyl)ethylene

Reaction of 2-(3-guaiazulenyl)-1,1-bis(4-hydroxyphenyl)ethylene with 2-chloroethyldimethylammonium chloride in acetone in the presence of K2CO3 at reflux temperature for 24 hours gives a new title compound in 89% yield. Spectroscopic properties and crystal structure of the target molecule are reported.

Solvent-Free Microwave Synthesis of Aryloxypropanolamines by Ring Opening of Aryloxy Epoxides

The ring opening reaction of aryloxyepoxides with isopropylamine under solvent-free microwave irradiation produced therapeutically useful -blockers-aryloxypropanolamines in excellent yield (up to 98%) in 10 minutes which is considerably less than the time taken in classical heating ( hours).

Synthesis and TDDFT Investigation of New Maleimide Derivatives Bearing Pyrrole and Indole Ring

A novel series of heterocycles were obtained through the condensation reaction of 4-methylthiomaleimides with pyrroles and indoles. The newly synthesized compounds exhibit their major electronic absorption peaks ranging 435–504 nm in solution at room temperature. Time-dependent density-functional theory (TDDFT) calculations were systematically performed in order to elucidate their structure-color relationships, using a set of exchange-correlation (XC) functionals. The TDDFT computational scheme employing PCM-TDDFT/6-31+G(d,p)//DFT/6-311G(d,p) level of theory gave qualitatively satisfactory results in their predictions.

Three-Component One-Pot Synthesis of Novel Benzo[b]1,8-naphthyridines Catalyzed by Bismuth(III) Chloride

A novel and efficient three-component one-pot synthesis of benzo[b]1,8-naphthyridines by 2-amino-4-methylquinoline, aromatic aldehydes, and malononitrile was done. The reaction was catalyzed by an acidic Bismuth(III) chloride, functionalized Bismuth(III) chloride, at room temperature to give various benzo[b]1,8-naphthyridines in high yields. The Bismuth(III) chloride is an environmentally friendly catalyst.

Cs2CO3/[bmim]Br as an Efficient, Green, and Reusable Catalytic System for the Synthesis of N-Alkyl Derivatives of Phthalimide under Mild Conditions

Aza-conjugate addition of phthalimide to α,β-unsaturated esters efficiently achieves in the presence of catalytic amount of Cs2CO3 and ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) under mild reaction conditions (70°C) to afford N-alkyl phthalimides in high yields and relatively short reaction times.

Synthesis and Biological Evaluation of 7-O-Modified Formononetin Derivatives

Three series of novel formononetin derivatives were synthesized, in which formononetin and heterocyclic moieties were separated by 2-carbon, 3-carbon, and 4-carbon spacers. The chemical structures of these compounds were confirmed. All the derivatives were screened for antiproliferative activities against Jurkat cell line and HepG-2 cell line. In this paper, compounds prepared were also screened for their antibacterial activity of six bacterial strains. Compound 3b exihibited promising antibacterial activity against B. subtilis with minimal inhibitory concentration (MIC) value of 0.78 μg/mL, and compound 5e showed significant antiproliferative activities against Jurkat cell growth with IC50 of 1.35×10−4 μg/mL. The preliminary investigation of structure-activity relationships (SARs) was also discussed based on the obtained experimental data.