Organic Chemistry

A highly efficient and expedient protocol for the synthesis of hydrazones catalyzed by citric acid is investigated via reaction of hydrazine hydrate with different carbonyl compounds. The use of inexpensive, non-hazardous easily available citric acid as a catalyst for the synthesis hydrazones employing grinding technique is reported. The structures of the synthesized compounds are established on the basis of physical, chemical and spectral data.

ABSTRACT A series of anthracene-based microporous polymers (AMPs) bridged by imide links were successfully prepared by conventional nucleophilic substitution reaction between several 9,10-dihydro-9,10-ethanoanthracenes and cheaper 2,3,5,6-tetrachlorophalonitrile (instead of fluoro-monomer)1. AMPs display a BET surface area in the range of 811-988 m2 g–1, and reversibly adsorb 1.59 wt. % H2 at 1.09 bar/77 K. The enhanced microporosity, in comparison to other organic microporous polymers prepared from (5,5’,6,6’-tetrahydroxy-3,3,3’,3’-tetramethylspirobisindane)2 originates from the macromolecular shape of framework, as dictated by the anthracene units, which helps to reduce intermolecular contact between the extended planar struts of the rigid framework. The impressive hydrogen adsorption capture of these materials verified by Horvath?Kawazoe (HK) and NLDFT analyses of low-pressure nitrogen adsorption data.

Some N-(substituted)-5,6-dimethylthieno[2,3-d]pyrimidin-4-amine derivatives 3(a-e) and 3-(substitutedphenyl)-1-(4-(5,6-dimethyl thieno [2,3-d]pyrimidin-4-ylamino)phenyl)prop-2-en-1-one derivatives 5(a-e) were synthesized starting from 2-amino thiophene-3-carboxylic acid ester analogue. The structures of all synthesized compounds have been evaluated by physical methods (melting point as well as elemental analyses) and also were confirmed by IR, 1H and 13C NMR spectroscopies. All the newly synthesized compounds were tested for their in vitro antimicrobial activity against gram (+)ve and gram (-)ve bacteria and also on different strains of fungi. Some of the compounds showed better antibacterial as well as antifungal activities in comparison with the standard drugs.

A series containing fourteen substituted styryl 5-methyl-2-furyl ketones [2E- 1(5-methyl-2-furyl)-3-(substituted phenyl)-2-propen-1-ones] were synthesized by Crossed-Aldol condensation between2-acetyl-5-methylfuron and various substituted benzaldehydes. The synthesized ketones were characterized by their physical constants and spectral data. The group frequencies of infrared absorption (cm-1) of ?COs-cis and s-trans, ?CHout of plane and in-plane, ?CH=CH out of plane, ?>C=C

The electrochemical polarographic analysis of complex of Re (II) complex with the ligand 1-{3-[2-Amino-5-(5-hydroxy-5H-imidazol-4-ylmethanesulfonyl)-benzyloxy]-4H-pyrazol-4-yl}-ethanone were analyzed and it found that ligand forms 1:2 complex with Re(II) in between pH of alkaline range between 7.4-8.6. The logarithm value of stability constant of 1:2 metalis 14.9and the entropy and free energy observed at -78.69 and -43.48 respectively.

The repeated column chromatography of the methanol extract leads to the isolation of compound (1), which was identified as 7, 8-Dihydroxy-2H-chromen-2-one (Daphnetin) for the first time from this species. The structure of the compound was elucidated on the basis of 1H, 13C, MS etc spectral techniques. HPLC analysis method was developed for the detection and confirmation of daphnetin in the methanol extract of Daphne oleoides, which clearly determined its presence in the extract (Chromatographic Finger print) after the calibration with isolated Daphnetin. Keywords: Coumarins, Daphne oleoides, Thymelaceae, HPLC, Daphnetin.

The objective of the present work was to synthesize co polymer hydrogel composed of (PAAc) and (PAAc / Pectin) which are very sensitive to environmental stimulus, this feature is important for their application in biomedical applications, due to its unique Properties which can resemble human living organs, Wound dressing, drug delivery systems. Gamma radiation induce synthesis and modification of monomer to polymer hydrogel was studied. The effect of different parameter onto preparation of smart hydrogel such as monomer concentration, radiation dose on to swelling percent of the prepared copolymer hydrogel have been studied, gel fraction have been studied as a function of swelling ratio. Structure characterization of the prepared copolymer hydrogel have been investigated using fourier transform infrared (FTIR) spectroscopy, The morphological structure using X–ray diffraction analysis and scanning electron microscopy (SEM) have been studied. The swelling properties of the prepared copolymers have been studied at different time and pH. It was found that the swelling percent increases as the time increase and increases as pH increase and the maximum swelling occurs at pH 6 with the value of 19000 % for (PAAc) hydrogel and 10000% for (PAAc/pectin) hydrogels after 24 h. Drug loading measurements using ciprofloxacin drug at pH7 for (PAAc) hydrogel after 24 h and at pH11 for (PAAc/pectin) hydrogels. Studies of drug releasing of ciprofloxacin as drug model have been investigated, at different time and pH and it was found that the drug release incases as pH increase and the maximum release occurs at pH4 for (PAAc) and pH ( 3 , 8) for (PAAc/pectin) hydrogels, the antimicrobial activity of the synthesized co polymeric hydrogel under study was evaluated based on the diameters of clear zone surrounding the polymeric substance ( disk diffusion test ) this proved that polymeric hydrogel can be used as antibacterial agent.

The reaction of 3-Methyl-1-phenyl- 1H-pyrazol -5-amine(1) with 3-(5-Arylfuran-2-yl)-1-arylprop-2-en-1-one(2a-l), formed a novel heterocyclic compounds, 6-(5-Arylfuran-2-yl)-3-methyl-1-phenyl-4-(4-substituedphenyl)-1H-pyrazolo[3,4-b]pyridine 3(a-l). The structures of all the compounds series (3a-l) were characterized analytically. The compounds were also monitored for anti microbial activity.

Synthesis of new series of 3-[4-(1-acetyl-5-(substitutedphenyl)-4,5-dihydro-pyrazol-3-yl)phenyl]-6,8-dibromo-2-methylquinazolin-4-one has been achieved by the refluxation of 6,8-dibromo-3-{4-[5-(substitutedphenyl)-4,5-dihydro-pyrazol-3-yl]phenyl}-2-methylquinazolin-4-one with Glycial acetic acid for three hours. The intermediate have been synthesized by refluxation of 6,8-dibromo-3-{4-[3-(substitutedphenyl)prop-2-enoyl]phenyl}-2-methylquinazolin-4-one (0.01M) and 99% hydrazine hydrate (0.015M) by using ethanol (50ml) as a solvent with various aldehydes. The chemical structures of synthesized acetyl pyrazoline derivatives were characterized by their physical constants and spectral data. The new acetyl pyrazoline derivatives were screened for their antimicrobial activities against several bacterial and fungal species.

The spectrophotometric characteristics of the solid charge-transfer molecular complexes (CT) formed in the reaction of the electron donor 5-amino-1-methyl-3-phenypyrazole (AMPP) with the ?-acceptors tetracyanoethylene (TCNE) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) and ?-acceptor iodine have been studied in chloroform at 25 0C. These were investigated through electronic and infrared spectra as well as elemental analysis. The results show that the formed solid CT- complexes have the formulas [(AMPP)(TCNE)], [(AMPP)(TCNQ)] and [(AMPP) I]+ I3- in full agreement with the known reaction stoichiometry in solution as well as the elemental measurements. The formation constant kCT, molar extinction coefficient ?CT, free energy change ?G0 and ECT energy have been calculated for the CT- complexes [(AMPP)(TCNE)], [(AMPP)(TCNQ)] and [(AMPP) I]+I-3.