Seranthimata Samshuddin

Antimicrobial, analgesic, DPPH scavenging activities and molecular docking study of some 1,3,5-triaryl-2-pyrazolines

A series of 1,3,5-triaryl-2-pyrazolines 2a–g were synthesized by the reaction of 4,4′-disubstituted chalcone with phenyl hydrazine. All these compounds were characterized by NMR, IR and mass spectral and single crystal XRD data. All the synthesized products were screened for their in vitro antimicrobial, analgesic and antioxidant properties. The docking studies were carried out for these compounds against the active site of methionyl-tRNA synthetase (metRS). Some of the tested compounds exhibited significant antimicrobial, analgesic, DPPH scavenging activities and molecular binding.

A study on the reactions of alkyl 4,6-bis(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate and in vitro antioxidant activity of derivatives

New functionalized derivatives were prepared using alkyl 4,6-bis(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate as a building block. Newly prepared compounds were well characterized using 1H NMR, IR, and mass spectral data. All the synthesized products were screened for their antioxidant properties. Among the tested compounds, indazole derivatives exhibited noticeable DPPH radical scavenging activity and reducing power capacity in comparison with the standard Glutathione.

Pseudosymmetry, polymorphism and weak interactions: 4,4′′-difluoro-5′-hydroxy-1,1′:3′,1′′-terphenyl-4′-carboxylic acid and its derivatives

The crystal structures of three derivatives of 4,4′′-difluoro-5′-hydroxy-1,1′:3′,1′′-terphenyl-4′-carboxylic acid are discussed. The acid itself (1), its ethyl ester (2)and hydrazide (3) have been chosen to study the influence of the hydrogen bonding potential on the crystal packing. In 1 and 2 short intramolecular O–H⋯O hydrogen bonds between the hydroxyl and carbonyl groups engage the strong hydrogen bond donors and acceptors, and both these compounds show the effects of packing conflicts. In 1 almost centrosymmetric, stable hydrogen-bonded dimers form between symmetry independent molecules, but the crystal structure is non-centrosymmetric and contains altogether four symmetry-independent molecules (two independent dimers), which show different pseudo-symmetries. In 2 dimer formation is impossible but two different crystal forms of this compound have been found. Both polymorphs crystallize in the P space group and differ mainly in the orientation of the OEt group. In turn in 3 there are no intramolecular hydrogen bonds and the crystal structure is determined mainly by the open motifs created by classical hydrogen bonds and by the complementarity of the respective hydrophilic and hydrophobic parts of the molecule.

Novel Reagents for the Spectrophotometric Determination of Isoniazid

Isoniazid is an antitubercular drug, widely used for tuberculosis. Owing to its importance in therapeutics, the present study aims to develop simple method for the spectrophotometric determination of isoniazid (INH). Two novel reagents, epichlorohydrine (ECH) and 4-hydroxyphenaylchloride (HPC) are used for the spectrophotometric determination of INH. Based on the nucleophilic substitution reactions of INH with EPI & HPC in basic medium, rapid, simple, inexpensive, precise, and accurate visible spectrophotometric method is proposed for the determination of INH in bulk drug and in formulations. Method involves the reaction of INH with EPI and HPC in basic medium to form yellow-colored chromogen, measuring the absorbances at 405 and 402 nm for INH-EPI & INH-HPC, respectively. The optimum experimental conditions have been studied. The absorbance was found to increase linearly with the concentration of the drug and formed the basis for quantification. The calibration graphs were linear from 2.00–22.00 μg mL−1 and 20.00–120.00 μg mL−1 for INH-EPI & INH-HPC, respectively. The apparent molar absorptivity and Sandells sensitivity are calculated to be 0.51×104 & 0.10×104 L mol−1 cm−1 and 0.027 & 0.134 μg cm−2 for INH-EPI & INH-HPC, respectively. The procedure is used to determine INH in pharmaceutical products. The associated pharmaceutical materials do not interfere in the measurements.

(2E)-3-[4-(1H-Benzimidazol-2-ylmethoxy)-3-methoxyphenyl]-1-(4,4''-difluoro-5'-methoxy-1,1':3',1''-terphenyl-4'-yl)prop-2-en-1-one

Novel terphenyl chalcone containing benzimidazole moiety (3) is synthesized by the base-catalyzed Claisen–Schmidt condensation of acetyl terphenyl derivative (1) with 4-(1H-benzimidazol-2-ylmethoxy)-3-methoxybenzaldehyde (2). Newly prepared chalcone derivative (3) is characterized by IR, NMR and mass spectral data.

tert-Butyl 1-(Furan-2-yl)-4-oxo-2,3,7-triazaspiro(4.5)dec-1-ene-7- carboxylate

A simple and novel route for synthesis of new spirocyclic compound is developed. The present work involves condensation of ethyl nipecotate with 2-furaldehyde followed by the MnO2 oxidation to give the β-keto ester which upon reaction with hydrazine hydrate gives the spiro pyrazolone.

Synthesis, Characterization, and Biological Evaluation of Some New Functionalized Terphenyl Derivatives

New functionalized terphenyl derivatives incorporating various heterocyclic rings are prepared by using 4,4′′-difluoro-5′-hydroxy-1,1′:3′,1′′-terphenyl-4′-carbohydrazide as a key intermediate derived from 4,4′-difluoro chalcone, a versatile synthone. All the derivatives are characterized by 1H NMR, IR, and mass spectral data. All the synthesized products are screened for their in vitro antimicrobial and antioxidant properties. The majority of the tested compounds exhibited significant antioxidant activity and some of them showed good antimicrobial activity.

A Review on 1,2,4-Triazole Derivatives as Corrosion Inhibitors

AbstractNumerous organic inhibitors have been reported for the corrosion inhibition of various metals. It is found that the synthetic heterocyclic compounds containing atoms with high electronegativity like nitrogen, sulphur, oxygen or phosphorous are very effective in preventing the corrosion of metals. In recent years, a trend is developed for analysing the compounds containing 1,2,4-triazole moiety for the corrosion inhibition of metals, as triazole nucleus containing three nitrogen atoms in a single ring. In this article, it is aimed to review the usefulness of 1,2,4-triazole derivatives for the corrosion inhibition of different metals and alloys in acid/base medium.

Three closely-related cyclohexanols (C35H27X2N3O3; X = F, Cl or Br): similar molecular structures but different crystal structures.

Three highly-substituted cyclohexanol derivatives have been prepared from 2-acetylpyridine and 4-halogenobenzaldehydes under mild conditions. (1RS,2SR,3SR,4RS,5RS)-3,5-Bis(4-fluorophenyl)-2,4-bis(pyridine-2-carbonyl)-1-(pyridin-2-yl)cyclohexanol, C35H27F2N3O3, (I), (1RS,2SR,3SR,4RS,5RS)-3,5-bis(4-chlorophenyl)-2,4-bis(pyridine-2-carbonyl)-1-(pyridin-2-yl)cyclohexanol acetone 0.951-solvate, C35H27Cl2N3O3·0.951C3H6O, (II), and (1RS,2SR,3SR,4RS,5RS)-3,5-bis(4-bromophenyl)-2,4-bis(pyridine-2-carbonyl)-1-(pyridin-2-yl)cyclohexanol, C35H27Br2N3O3, (III), all crystallize in different space groups, viz. Pbca, Fdd2 and P1, respectively. In compound (II), the acetone molecule is disordered over two sets of atomic sites having occupancies of 0.690 (13) and 0.261 (13). Each of the cyclohexanol molecules contains an intramolecular O-H···N hydrogen bond and their overall molecular conformations are fairly similar. The molecules of (I) are linked by two independent C-H···O hydrogen bonds to form a C(5)C(10)[R2(2)(15)] chain of rings, and those of (III) are linked by a combination of C-H···O and C-H···N hydrogen bonds, forming a chain of alternating R2(2)(16) and R2(2)(18) rings. The cyclohexanol molecules in (II) are linked by a single C-H···N hydrogen bond to form simple C(4) chains and these chains are linked by a π-π stacking interaction to form sheets, to which the disordered acetone molecules are weakly linked via a number of C-H···O contacts.

N-(3,4-Dimethoxyphenyl)-4-oxo-2,3,7-triazaspiro[4.5]dec-1-ene-1-carboxamide Hydrochloride

A simple and novel route for synthesis of new spirocyclic amide derivative is developed. The present work involves the oxidative cleavage of tert-butyl 1-(furan-2-yl)-4-oxo-2,3,7-triazaspiro[4.5]dec-1-ene-7-carboxylate 1 followed by the amine coupling and deprotection of Boc.