Parvez Ali

Microwave assisted synthesis and characterization of N,N′-bis(salicylaldehydo)ethylenediimine complexes of Mn(II), Co(II), Ni(II), and Zn(II)

Microwave chemistry is a green chemical method that improves reaction conditions and product yields while reducing solvent amounts and reaction times. The main aim of this article is to synthesize the tetradentate N2O2 ligand [HO(Ar)CH=N–(CH2)2–N=CH(Ar)OH] and manganese(II), cobalt(II), nickel(II), and zinc(II) complexes of the type ML by classical and microwave techniques. The resulting Schiff base and its complexes are characterized by 1H NMR, infrared, elemental analysis, and electronic spectral data. The ligand and its Co(II) and Mn(II) complexes were further identified by X-ray diffraction and mass spectra to confirm the structure. The results suggest that the metal is bonded to the ligand through the phenolic oxygen and the imino nitrogen.

Exploring microwave synthesis for co-ordination: synthesis, spectral characterization and comparative study of transition metal complexes with binuclear core derived from 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one

A series of transition metal complexes of Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Hg(II), and Sn(II) has been synthesized from the Schiff base (L) derived from 4-aminoantipyrine and 4-fluoro-benzaldehyde using traditional synthetic methodology and microwave-induced organic reaction enhancement (MORE) technique. A benign, simple, and versatile route to a Schiff-base ligand and its metal complexes has been explored. Neat reactants were subjected to microwave irradiation giving the required products more quickly and in better yield compared to the classical methodology. Structural features were obtained from elemental analysis, molar conductivity, 1H-NMR, mass, UV-Vis, and FTIR spectroscopy and X-ray diffraction. The data show that these complexes are ML2. The MORE method for synthesis is easy, convenient, and ecofriendly as compared to the traditional synthetic method.

Microwave Assisted Synthesis and Antimicrobial Study of Schiff Base Vanadium(IV) Complexes of Phenyl Esters of Amino Acids

Schiff base vanadium(IV) complexes of phenyl esters of the two acidic amino acids, i.e., aspartic and glutamic acid, were synthesized. The phenyl esters of these amino acids were synthesized by conventional method whereas the Schiff base vanadium(IV) complexes were synthesized using microwave irradiation. The complexes were characterized by spectroscopic tools such as IR, 1 H NMR, mass (ES), ESR, and UV visible spectroscopy. All the complexes were studied for antibacterial and antifungal activity and found to be moderately active.

Predictions and correlations of structure activity relationship of some aminoantipyrine derivatives on the basis of theoretical and experimental ground

A series of 4-aminoantipyrine derivatives were produced by condensing aromatic primary amine, namely, 4-aminoantipyrine with different aryl carbonyls which occurred cleanly and efficiently without using any catalyst at room temperature. Their structures were confirmed on the basis of 1H NMR, IR, Mass spectra, and elemental analysis. The synthesized library was screened virtually using versatile bioinformatics parameters owing to the quick access, biological response, and utility of the produced moieties. The virtually screened molecules were subjected to screen practically against certain some strain of microorganisms: Staphylococcus aureus (Gram positive), Pseudomonas vulgaris (Gram positive), Pseudomonas Aeruginosa (Gram negative), and Escherichia coli (Gram negative). A correlation of structure and activities relationship of these compounds with respect to molecular modeling, Lipinski rule of five, drug-likeness, toxicity profiles, and other physico-chemical properties of drugs is described and verified experimentally.

Zeolite as an efficient and recyclable activation surface for the synthesis of bis-thiazolidinones: theoretical screening owing to experimental biology

Abstract Zeolite 5Å has been used as an efficient and cost effective activating catalyst for the synthesis of bis-thiazolidinones 4 (a–h) starting from bis-imines 3 (a–h) and thioacetic acid. The reactions were performed under microwave irradiation in solventless condition. The catalyst was recycled and used for several times. This reaction is scalable to multigram scale and the methodology has resulted in an efficient synthesis. A benign, environmentally friendly, efficient, and extremely fast procedure for synthesis of bis-thiazolidinones has been demonstrated. The produced bis-thiazolidinone molecules were characterized on the basis of elemental analysis, IR, mass, and 1H-NMR spectral data. The synthesized moieties were screened virtually using some of bioinformatical softwares and discussed.

Eco-friendly development: synthesis of 3-(2-chloroquinolin-3-yl)-1-aryl prop-2-en-1-one using K2CO3–Al2O3 under ultrasonic radiations

Abstract K2CO3–Al2O3 has been used as an efficient, eco-friendly, and cost-effective activating catalyst for the synthesis of 3-(2-chloroquinolin-3-yl)-1-substituted phenyl prop-2-en-1-ones starting from 2-chloroquinoline-3-carbaldehyde and acetophenone. The reactions were performed under ultrasound irradiations. A substantial enhancing effect in the yield was observed when the catalyst was activated under ultrasonic waves. The K2CO3–Al2O3 catalyst can compete with the traditional NaOH/MeOH system of catalysis when the reaction is carried out under ultrasound. Herein, a benign, eco-friendly, efficient, and extremely fast procedure for the synthesis of quinoline chalcones has been demonstrated successfully.

Greener Synthetic and Nanotechnological Bridge: Theoretical and Practical Biological Approach Toward the Bactericidal Dual Action Mechanism of Azomethine–Nanosilver Hybrid

ABSTRACT An efficient, clean, cheap, and quick procedure for the condensation of aromatic primary amine, namely, 4-aminophenazone, with different aryl carbonyls to produce azomethines under solvent-free and catalyst-free conditions at room temperature has been described. Their structures were confirmed by 1H-nuclear magnetic resonance (NMR), infrared (IR), mass spectra, and elemental analysis. The corresponding azomethines has been screened virtually using bioinformatical parameters on the basis of hypothetical antibacterial pharmacophore structure designed to interact with both of gram-positive bacteria and gram-negative bacteria. The virtually screened molecules were subjected to screening against certain strains of gram-positive and gram-negative bacteria. Based on the results of initial screening, the bactericidal action of some selected compounds has been increased by hybrid coupling with silver nanoparticles. The results thus obtained are discussed.

Benign Methodology and Efficient Catalysis for the One-Pot Multicomponent Synthesis of Dihydropyrimidinones and Thiones: A New Key for Old Lock

In the present communication, under the influence of microwaves, cuprous chloride has been demonstrated to be safe, mild, efficient, and inexpensive catalyst for the Biginelli discovered multicomponent reaction (MCR) between aromatic aldehydes, urea/substituted urea, and ethyl acetoacetate to produce structurally diverse dihydropyrimidin-2(1H)-ones (DHPMs) and thiones in an ecofriendly solvent-free protocol. The practical and simple protocol led to excellent yields of the dihydropyrimidin-2(1H)-one derivatives under mild reaction conditions and within short span of reaction times with easy reaction workup by maintaining excellent atom economy.

Novel oxazine skeletons as potential antiplasmodial active ingredients: Synthesis, in vitro and in vivo biology of some oxazine entities produced via cyclization of novel chalcone intermediates

A novel series of 6-(2-chloroquinolin-3-yl)-4-substituted-phenyl-6H-1,3-oxazin-2-amines were synthesized and evaluated for in vitro antimalarial efficacy against chloroquine sensitive (MRC-02) as well as chloroquine resistant (RKL9) strains of Plasmodium falciparum. The activity tested was at nanomolar concentration. β-Hematin formation inhibition activity (BHIA50) of oxazines were determined and correlated with antimalarial activity. A reasonably good correlation (r = 0.49 and 0.51, respectively) was observed between antimalarial activity (IC50) and BHIA50. This suggests that antimalarial mode of action of these compounds seems to be similar to that of chloroquine and involves the inhibition of hemozoin formation. Some of the compounds were showing better antimalarial activity than chloroquine against resistant strain of P. falciparum and were also found to be active in the in vivo experiment.

In Search of Benign Methodologies for Coordination: Synthesis, Characterization, and in vitro Biology of Transition Metal Complexes of N, N′-bis (salicylidine) toluene-2, 4-diamine with Binuclear Core

A series of transition metal complexes of Zn(II), Co(II), Cu(II), Ni(II), and Mn(II) have been synthesized from Schiffs base H2Sal-2,4-toluene, [N,N′-bis(salicylidine)toluene-2,4-diamine] (IV) derived from salicylaldehyde and toluene 2,4-diamine using MORE technique. Structural features were obtained from FTIR, UV-VIS, molar conductance, ELEMENTAL analysis, 1H-NMR, mass spectral and X-ray diffraction studies, which have shown the formation of dimer complexes, where the ligand acts as a bridge between two metal cations. Ligand and complexes have been screened experimentally for their antimicrobial activity against different species of pathogenic bacteria; Viz., E. coli, S. aureus, B. subtilis and P. aureginosam and their antimicrobial potency have been discussed.