Hamdi Özkan

The synthesis and investigation of the antimicrobial activity of some new phenylselanyl-1-(toluene-4-sulfonyl)-1H-tetrazole derivatives

The sulfonamide functional group has aroused interest in both medicinal and bioorganic chemistry. In this study, some new phenylselanyl–1–(toluene-4-sulfonyl)-1H-tetrazole derivatives (2a–f) have been synthesized using dicyclohexylcarbodiimide/dimethylaminopyridine (DCC/DMAP). The structures of the presently synthesized compounds were elucidated by spectroscopic methods [Fourier-transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (NMR), 13C nuclear magnetic resonance-attached proton test (13C NMR-APT), and mass spectrometry (MS)]. In addition, the antimicrobial activity of the synthesized compounds and two antibiotics [sulfamethoxazole (SMX) and sulfamerazine (SRZ)] were investigated against some microorganisms.Graphical AbstractThe synthesis and investigation of the antimicrobial activity of some new phenylselanyl-1-(toluene-4-sulfonyl)-1H-tetrazole derivativesYılmaz Yıldırır, M. Faruk Us, Naki Çolak, Hamdi Özkan, Serkan Yavuz, Ali Disli, Sahlan Ozturk, Lemi TurkerIn this study, some new phenylselanyl–1–(toluene-4-sulfonyl)-1H- tetrazole derivatives, 2a–f, have been synthesized using DCC/DMAP. In addition to, antimicrobial activity of synthesized compounds and two antibiotics (SMX, SRZ) were investigated against some microorganisms. Reagents and conditions: (i) HCI, (ii) EtONO, -5 – 0°C; (iii) KSeCN, (iv) NaN3, Et3NH+ CI−, Toluene. 2a. R1:H, R2:Cl 2b. 2a. R1:H, R2:CH32c. R1:Cl, R2:H 2d. R1:Br, R2:H 2e. R1:I, R2:H 2f. R1:CH3, R2:H

A Novel Synthesis of Bromobenzenes Using Molecular Bromine

Certain substituted bromobenzenes have been synthesized in acceptable yields using a novel Sandmeyer type reaction. The reactions are relatively quick and possibly proceed via a radical mechanism.

Fast method for synthesis of alkyl and aryl-N-methylnitrones.

A simple, fast, efficient and eco-friendly procedure was developed for the synthesis of alkyl and aryl-N-methylnitrones. The corresponding nitrones of aromatic aldehydes, aliphatic aldehydes and alicyclic carbonyl compounds were prepared from N-methylhydroxylamine hydrochloride and Na2CO3-Na2SO4 by simply grinding at room temperature without using solvent.

IMPROVED SYNTHESIS OF PHENYLSELENOGLYCOLIC ACIDS

Selenium is a nonmetallic trace element recognized as a nutrient essential to human health.’** Selenium is also an essential constituent of extracellular and cellular glutathione peroxidases, thyroidal and extrathyroidal iodothyronine 5’-deiodinnases, thioredoxin reductase, and other selenoproteins.2 Various experimental models showed that selenium inhibits tum~rigenesis.~ Low serum selenium levels are associated with an increased risk of developing cancer at several sites, especially cancers of the stomach and lung for men4. Thus, many organoselenium compounds have been ~ynthesized.’,~ Some substituted phenylselenoglycolic acids have been synthesized by using Grignard reagent’ (Scheme I) (yields 20-2596) and from

Synthesis and DNA binding of new adenine derivatives incorporating 5-((Alkylthio)-1,3,4-oxadiazol-2-yl)methyl moiety

In this study, a series of new adenine derivatives possessing 1,3,4-oxadiazole moiety with different S-alkyl group were synthesized. The structures of these compounds were established on the basis of FT-IR, 1H, 13C-APT NMR, and HRLC-MS spectral data. Their DNA binding abilities were investigated in vitro by agarose gel electrophoresis. The relationship between the structure and the mentioned biological activities was discussed. The results showed that these compounds 5d and 5c exhibited DNA cleavage activity. Compounds DNA interaction studies reveal that compounds have affinity towards A/A and G/G nucleotides on DNA. None of the compounds at 2500 µM concentration have no inhibitory effect on microbial growth of tested strain of bacteria and yeast strain used in this study.

Dimethyl cis-2-methyl-3-p-tolyl­isoxazolidine-4,5-dicarboxyl­ate

In the molecule of the title compound, C15H19NO5, the isoxazole ring adopts an envelope conformation. In the crystal structure, weak intermolecular C—H⋯O and C—H⋯N hydrogen bonds link the molecules, in which they may be effective in the stabilization of the structure.

(3R,3aS,6aR)-2,5-Dimethyl-3-(5-phenyl-2-thien­yl)perhydro­pyrrolo[3,4-d][1,2]oxazole-4,6-dione

The crystal structure of the title compound, C17H16N2O3S, exhibits intramolecular C—H⋯S and intermolecular C—H⋯S and C—H⋯O hydrogen bonds, C—S⋯N [S⋯N = 3.033 (2) Å and C—S⋯N = 142.76 (9)°] interactions, and C—H⋯π interactions; these interactions generate S(4), S(6) and R 2 2(14) ring motifs. The isoxazole ring adopts an envelope conformation, with the N atom displaced by 0.672 (2) Å from the plane of the other ring atoms. The thiophene ring is oriented with respect to the succinimide and phenyl rings at dihedral angles of 40.03 (12) and 5.21 (13)°, respectively. The dihedral angle between the succinimide and phenyl rings is 39.38 (12)°.

2,5-Dimethyl-3-(3-methyl-thio-phen-2-yl)perhydro-pyrrolo[3,4-d]isoxazole-4,6-dione.

The crystal structure of the title compound, C12H14N2O3S, exhibits intramolecular C—H⋯S and intermolecular C—H⋯S, C—H⋯O hydrogen bonds, C—S⋯N [S⋯N = 2.980 (2) Å, C—S⋯N = 145.78 (17)°] and C—H⋯π interactions; these interactions generate two C(5) chains and S(4), S(6) and R 4 4(28) ring motifs. The isoxazole ring has an envelope conformation; the N atom, which is the flap atom, is displaced by 0.261 (2) Å from the plane defined by the remaining four atoms. The dihedral angle between the succinimide and thiophene rings is 46.8 (2)°.