Zeolite‐Supported One‐Pot Synthesis of Bis‐azetidinones under Microwave Irradiation

In an attempt to synthesize antibacterial agents effective against gram‐positive and gram‐negative bacteria, the efficient synthesis of novel bis‐azetidinones ( 3a–j ) has been established. Thus, cycloaddition reaction of substituted bis‐imines with chloroacetylchloride under microwave irradiation in the presence of zeolite yielded bis‐azetidinones ( 3a–j ). Structures of the synthesized compounds have been elucidated on the basis of their elemental analysis and spectral data (IR, ¹H‐NMR, ¹³C‐NMR, and mass spectra). The synthesized bis‐azetidinones were screened for their antibacterial activity against five microorganisms: Bacillus subtilis, Proteus vulgaris, Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli. They were found to exhibit good to moderate antibacterial activity.     

Efficient Synthesis,Characterization, In Vitro Antibacterial and Antifungal Activity Study and Computational Tool for Prediction of Molecular Properties of Some Novel Schiff's Base via Betti's Protocol and Azetidinones

Series of new substituted pyrazolone derivatives via Betti's condensation reaction of pyrazolone and different aldehydes has been reported successfully under ambient reaction conditions. The structural elucidation of newly synthesized compounds was done using analytical and spectroscopic tools such as elemental analysis, ¹H NMR, ¹³C NMR, and mass spectroscopy. Physicochemical parameters, toxicity profiles and drug likeness properties were studied using various bioinformaticals tools like Osiris and molinspiration. These results viz., the good correlations between the inhibitory activities and the computational values make the molecules available for future protein–ligand interaction studies. It further provided useful information in understanding the structural and chemical features of the drug in designing and finding new potential inhibitors.     

Anti-corrosive property of bioinspired environmental benign imidazole and isoxazoline heterocyclics: A cumulative studies of experimental and DFT methods

In the present study, four imidazoline (IDZ) and four isoxazolines (ISO) heterocyclics differing in the nature of methoxy (-OCH₃) and aromatic (phenyl and naphthyl) moieties are synthesized, characterized and evaluated as corrosion inhibitors for mild steel in acidic solution of 1 M HCl. Results showed that imidazoline based heterocyclic compounds are better corrosion inhibitors than isoxazoline based heterocyclics and both classes of compounds showed inhibition efficiency of more than 85% at 20 mgL⁻¹ concentration. Results further showed that inhibitors containing methoxy, phenyl, and naphthyl moieties showed higher protection efficiency as compared to the inhibitors without these moieties. PDP Study revealed that investigated IDZs and ISOs acted as mixed type inhibitors and their adsorption on the metallic surface followed the Langmuir adsorption isotherm model. All the experimental results were corroborated by density function theory (DFT) based quantum chemical calculations. Numerous DFT based indices calculated for neutral as well as protonated forms of the IDZs and ISOs in order to get better insight about metal-IDZs/ISOs interactions. Outcomes of the DFT analysis showed that protonated (cationic) form of the all the inhibitors are more strongly adsorbed on the metallic surface as compared to their neutral form.     

Pressure induced structural phase transition and electronic properties of actinide monophospides: Ab-initio calculations

We have investigated the structural and electronic properties of monophospides of thorium, uranium and neptunium. The total energy as a function of volume is obtained by means of the self-consistent tight binding linear muffin-tin-orbital (TB-LMTO) method within the local density approximation (LDA). From the present study with the help of total energy calculations it is found that ThP, UP and NpP are stable in NaCl-type structure at ambient pressure. The structural stability of ThP, UP and NpP changes under the application of pressure. We predict a structural phase transition from NaCl-type (B₁-phase) structure to CsCl-type (B₂-phase) structure for these phospides in the pressure range of 37.0-24.0 GPa (ThP-NpP). We also calculate lattice parameter (a₀), bulk modulus (B₀), band structure and density of states. From energy band diagram it is observed that ThP, UP and NpP exhibit metallic behavior. The calculated equilibrium lattice parameters and bulk modulus are in good agreement with experimental and theoretical work.     

Synthesis,characterization and antibacterial activity of 1-([6-bromo-2-hydroxy-naphthalen-1-yl]arylphenyl)methyl)-3-chloro-4-(arylphenyl)-azetidin-2-one

One-pot synthesis of 1-([6-bromo-2-hydroxy-naphthalen-1-yl]-aryl-phenyl)methyl)-3-chloro-4-(aryl-phenyl)azetidin-2-ones has been reported in the present research work via Staudinger [2 + 2] ketene-imine cycloaddition reaction pathway. The reaction of 1-((Benzylideneamino)(aryl)methyl)-6-bromo-naphthalen-2-ols with chloroacetic acid and triethylamine afforded 1-([6-bromo-2-hydroxynaphthalen-1-yl]aryl-phenyl)methyl)-3-chloro-4-(aryl-phenyl)azetidin-2-ones. For the structural elucidation of series of compounds, different analytical and spectroscopic techniques such as elemental analysis, IR spectra, ¹H-NMR spectra and mass spectra were used. All the newly synthesized compounds were tested for their anti-bacterial activity studies. It revealed that some of the compounds possesses moderate to good activities as compared to standard drugs. The widest spectrum of anti-bacterial activities against both gram-positive and gram-negative bacterial strains among the examined compounds possessed having more hydroxyl group along with β-lactam ring compared to other substituted azetidinones.     

Design and synthesis of new derivatives of 3H‐quinazolin‐4‐one as potential anticonvulsant agents

As a part of systematic investigation on synthesis and biological activities, some new derivatives of 2‐ethyl‐3‐(substituted benzothiazole‐2′‐yl)–[3H]‐quinazolin‐4‐ones 3 have been synthesized, and the structures of the compounds were confirmed by elemental analysis and spectral data. The newly synthesized derivatives are then screened for anticonvulsant activity by maximal electroshock method. J. Heterocyclic Chem., (2011).     

Synthesis,characterization, antibacterial and antifungal activity of 2‐(aryl)‐3‐(3‐((8‐hydroxyquinolin‐5‐yl)diazenyl)phenyl)thiazolidin‐4‐ones

5‐((3‐Aminophenyl)diazenyl)quinolin‐8‐ol ( 1 ) was synthesized by diazotization reaction and coupled with 8‐hydroxyquinoline moiety. This amine on facile condensation with aromatic aldehydes in presence of glacial acetic acid and ethanol affords anils ( 2 ). These anils on cyclocondensation reaction with thioglycolic acid (i.e., mercaptoacetic acid) yield the titled compound ( 3 ). The structure of the newly synthesized anils ( 2 ) and thiazolidinones ( 3 ) has been confirmed by elemental analysis and spectral analysis. The titled compounds have been screened against different bacterial and fungal strains. J. Heterocyclic Chem., (2011).     

An expeditious one‐pot synthesis of substituted phenylazetidin‐2‐ones in the presence of zeolite

In this study, one‐pot rapid and efficient series of phenylazetidin‐2‐ones were synthesized from N,N‐dimethylaminobenzaldehyde, different substituted aromatic amines and phenylacetyl chloride in the presence of zeolite catalyst under microwave irradiation. We also reported schiff bases (1a–j) by classical and conventional microwave technique. The titled compounds are evaluated for their antimicrobial properties. The activities are due to C?O, C? N, linkages in 2‐azetidinones. All the compounds have shown comparable antibacterial activities. J. Heterocyclic Chem., (2011).