Organic Chemistry

Newly designed 2-azetidinone derivatives (4a-e) were synthesized in good yields and characterised by advanced spectroscopic studies. The title compounds were evaluated for qualitative (zone of inhibition) by agar diffusion method against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Streptococcus pyogenes. Some of the analogues were found to have comparable or even more potency than the standard drugs. Docking study was performed to check interaction of synthesized compounds with the target DNA gyrase.

The novel organotin(IV) complexes such as (p-ClBz)2SnBr2. Phen(2a) and (p-BrBz)2SnBr2. Phen(2b) were synthesized and characterized employing 1H, 13C and 119Sn NMR analyses. The spectral studies revealed the complex formation of 1,10-phenanthroline with p-substituted diorganotin dibromides at normal reaction conditions. Single crystal diffraction of 2a and 2b has confirmed that the tin atom is in regular octahedral geometry with the benzyl group in the equidirectional position. The structures of these compounds have been characterized by FT-IR, FT-Raman techniques. The optimized geometrical parameters, vibrational wavenumbers, corresponding vibrational assignments of the complexes 2a and 2b have been investigated by means of the density functional theory. The vibrational frequencies were calculated and scaled values were compared with experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found to be in good agreement. Moreover, the molecular electrostatic potential surfaces of the complexes have been constructed and electronic property such as HOMO and LUMO energies were also performed.

This study compared the concentration of ascorbic acid between citrus fruits collected from farm of Kerman in Iran. Determination of ascorbic acid was carried out using a liquid chromatograph coupled to a diode array detector, with reverse phase and isocratic elution. The validation parameters showed efficiency, adequate linearity, relative standard deviation values 0.02 % (n=10) for repeatability and 0.5 % (n=15) for reproducibility, limit of detection (LD) was 0.2 mg L-1 recovery was between 97.3 % and 103.6%. Ascorbic acid 10 species of citrus: sour and sweet orange, umbilical orange, novel orange ,lime, lemon, pink and white grapefruit, aegle marmelos, bergamot, sour and sweet tangerines and clementine was determined. The average ascorbic acid was the highest in Shahdad’s citrus fruits.

4-oxo-thiazolidine have been synthesized by cyclisation of acyclic compounds and thioglycolic acid on Schiff ’s bases. All the products have been evaluated for their in vitro antimicrobial activity against various strains of bacteria.

Gulf heavy crude oil samples were separated into four fractions of saturates, mono-, di- and polyaromatics by elution open column chromatography. Alumina and a mixture of equal amount of silica and alumina stationary phases were separately used to study the effect of these stationary phases on the separation. The Gas Chromatography – Mass Spectrometry (GC – MS) results of the fractions show that the nature of the stationary phase may affect the elution of both aromatic and the saturate components of the oil. The pristane/phytane ratio ranging from 0.63-2.00 obtained for the crude oil fractions using the two stationary phases indicates an oxygen depositional environment for the source rocks.

4- Oxo- thiazolidines substituted in 2 and 3 positions exhibit a wide range of biological activities. A series of 4-oxo-thiazolidine (4 a-o) have been obtained by cyclisation of various Schiff’s base (3) with thiomalic acid. The Schiff’s bases (3) are obtained by the reaction of 4 – Methyl cinnamoyl hydrazine with appropriate benzaldehyde. The product is characterized by spectral and analytical data. Most of the tested compounds show promising antibacterial activity.

Conductive polymers are good candidates for preparation of conducting graft copolymers. Therefore, polyaniline (PANI) was chemically grafted with chitosan by using ammonium peroxydisulfate (APS) initiator to obtain a product called as chitosan-graft-polyaniline (CHIT-g-PANI). Polyaniline, chitosan and CHIT-g-PANI were characterized by fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy, X-Ray diffraction (XRD) and scanning electron microscopy (SEM). UV –vis and FT-IR studies confirmed the chemical structure and conjugation of CHIT-g-PANI. FTIR studies suggested the graft copolymerization of polyaniline on to chitosan. XRD of the CHIT-g-PANI further evidenced the grafting. The surface structure of CHIT-g-PANI was also verified by SEM.

In this work, an attempt was made to synthesize chalcones 3-(Substitutedphenyl)-N-(4H-1,2,4-triazol-4-yl)acrylamide by condensation of Substitutedbenzaldehyde with N-(4H-1,2,4-triazol-4-yl)acetamide under basic conditions by using both conventional and Microwave synthesis methods. A simple condensation reaction of substiutedbenzaldehyde and N-(4H-1,2,4-triazol-4-yl)acetamide using Sodium hydroxide as a base was carried out for the study. The synthesized chalcone derivatives were characterized for FTIR, 1H NMR, 13C NMR and Mass spectral analysis. It was observed that complete conversion to chalcone occurred in 10-12 min by Microwave synthesis method and in 10 h by conventional method. Finally, it has been observed that chalcone synthesis using Microwave synthesis method is a Convenient, Rapid and Eco-Friendly Synthesis over conventional method. The reaction time has been brought down from hours to seconds with improved yield as compared to conventional heating.

Non-traditional method (grinding) was used for the preparation of novel schiff bases from 4-amino-3-methyl phenol / 2-amino-4-methyl phenol and several aldehydes and ketones under catalytically free condition. This procedure constitutes an energy efficient, shorter time, higher yield as well as green synthesis approach. Some synthesized products were characterized by IR, NMR and MASS and also tested for antibacterial (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumonae) activities by disc diffusion method

The Baylis-Hillmann reaction of 8-formyl-7-hydroxy furyl chromones on react with Acrylonitrile in DABCO/CHCl3 medium under nitrogen atmosphere at room temperature gives of 2-(2-furyl)-3-methyl-4oxo-4H,8H-pyrano[2,3-f]chromene-9-carbonitrilies (4a-h) in good yields.