Organic Chemistry

Manmade disasters wrap an ample range of events produced largely due to negligence, accidents, or sometimes even by human design and its errors. These also include the threats of nuclear, biological and chemical disasters. This emphasized the regular check and modification in current scientific solutions and to promote the quest of ‘Go Green’. Water source can be used for pioneering scientific solutions at laboratory level and to resolve the scientific & environmental issue. It is in abundant source on earth and versatile in nature to behave as a communicator for various chemical/biological reactions. This solvent is best green solvent for various chemical and biological processes the utility ad its superiority over others have been investigated and evaluated.

1,5-benzothiazepine is the main seven-membered heterocyclic ring system and having several cardiac, psychotherapeutic activities. Which has been synthesized by catalytic amount of piperidine mediated condensation of dry toluene with Prenyloxy chalcones (3) and 5-substituted-2-Amino benzenethiols (2). The corresponding prenyloxy chalcones (3) were synthesized by piperidine mediated claisen-schemidt condensation of an ethanolic solution of 4-prenyloxy 2-hydroxy acetophenone (1) with aromatic aldehydes. It was planned to use a weaker base like piperidine instead of using strong base to enhance the better yields. The structures have been established on the basis of elemental (C, H, N) analysis, IR, 1H NMR, Mass spectral data. The compounds (3) and (5) were screened for antimicrobial activities against a variety of bacterial agent.

Novel bioactive molecules are designed by using molecular hybridization techniques which is based on the recognition of pharmacophoric sub-unities in the molecular structure of two or more known bioactive derivatives. Adequate fusion of these sub-unities, lead to the design of new hybrid architectures that maintain pre-selected characteristics of the original templates. All the designed molecules were than synthesized and evaluated for their antimicrobial activity.

The FT-IR and FT-Raman spectra of 2-bromo-m-xylene (2BMX) have been recorded in the regions 4000–400 cm?1 and 4000–100 cm?1, respectively. The fundamental vibrational frequencies and intensities of the vibrational bands were evaluated using density functional theory (DFT) using standard B3LYP method and 6-311+G** basis set combinations. The vibrational spectra were interpreted, with the aid of normal coordinate analysis based on a scaled quantum mechanical force field. The Infrared and Raman spectra were also predicted from the calculated intensities. The Mulliken population analysis of the molecule is computed by using DFT calculations. The calculated HOMO and LUMO energies shows that charge transfer occur within the molecule. Further, density functional theory (DFT) combined with quantum chemical calculations to determine the first-order hyperpolarizability. Electronic excitation energies, oscillator strength and nature of the respective excited states were calculated by the closed-shell singlet calculation method were also calculated for the molecule.

About 15mol% of ZrOCl₂.8H₂O in ethanol has been found to be an efficient catalyst for the multi-component synthesis of dihydro-1H-Indeno [1,2-b] pyridines by the reaction between 1,3-indandione, ethylacetoacetate, aromatic aldehyde and ammonium acetate at reflux condition. Atom economy, excellent yields, simple workup and mild reaction conditions are some of the important features of this method.

Recently, the synthesis of furoinoxime, furoinhydrazone, furoinphenylhydrazone, furoinsemicarbazone were synthesized by the interactions of furoinbenzoin with hydroxylamine hydrochloride, hydrazine hydrate, phenyl hydrazine and semicarbazide hydrochloride in presence of aqueous sodium hydroxide in DMF-water (80%) medium respectively. The synthesis of furoinbenzoin were carried out by the known literature method. The structure of all the synthesized compounds were justified on the basis of chemical characteristics, elemental and I.R. and NMR spectral analysis. Keywords :- Sodium hydroxide, DMF-water (80%) medium, substituted benzoinoximes, furoinbenzoinoximes.

4-Oxothiazolidines(1a-o) have been synthesized by cyclisation of various Schiff bases with thiolactic acid. The schiff bases are obtained by the condensation reaction of 4-methyl cinnamoyl hydrazine with different benzaldehydes. The synthesized compounds are identified on the basis of spectral and elemental analysis. All the products have been evaluated for their in vitro antimicrobial activity against various strains of bacteria.

An electrophilic substitution reaction of indole with variety of carbonyl compounds catalyzed by stannous chloride dihydrate in presence of aqueous medium has been investigated. The offered green method provided the target molecules in better yields and less reaction time at room temperature.

Vibrational spectral analysis was carried out for 2-chloro-1-fluoro-4-nitrobenzene (CFNB) by using the FT-IR and FT-Raman spectroscopy in the range of 4000 cm-1 to 400 cm-1 and 4000 cm-1 to 100 cm-1 respectively. The theoretical computational density functional theory (DFT/B3LYP) was performed at 6-311+G** levels to derive equilibrium geometry, vibrational wavenumbers, infrared intensities and Raman scattering activities. The complete vibrational assignment was performed on the basis of the potential energy distribution (PED), calculated with scaled quantum mechanics (SQM) method. Natural bond orbital (NBO) analysis was applied to study stability of the molecule arising from charge delocalization. Quantum chemical parameters such as the highest occupied molecular orbital energy (HOMO), the lowest unoccupied molecular orbital energy (LUMO), energy gap (?E), were calculated.