Naki Çolak

Synthesis and biological activity of new cycloalkylthiophene-Schiff bases and their Cr(III) and Zn(II) complexes

A series of some novel Ethyl 2-((1-hydroxynaphthalen-2-yl)methyleneamino)-5,6-dihydro-4H-cyclopenta[b]thiopehene-3-carboxylate, Ethyl 2-((1-hydroxynaphthalen-2-yl)methyleneamino)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate, Ethyl 2-((1-hydroxynaphtalen-2-yl)methyleneamino)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxylate and their Cr(III) and Zn(II) complexes have been synthesized. All of these substances have been examined for antibacterial activity against pathogenic strains Listeria monocytogenes 4b (ATCC-19115), Staphylococcus aureus (ATCC25923), Proteus OX2 Wrah (ETS.40-A-4), Escherichia coli (ATCC-1280), Salmonella typhi H (NCTC-901.8394), Pseudomonas putida sp., Brucella abortus (A.99, UK-1995) RSKK-03026. Sh. boydii type 11 (Pasteur51.6), Sh. boydii type 16 (cHe 67.11), Sh. boydii type 6 (RSKK-96043), and antifungal activity against Candida albicans (Y-1200-NIH, Tokyo). Some of the compounds exhibited activity comparable to ampicillin ofloxacin, nystatin, kanamycin, sulphamethoxazol, amoxycillin, and chloroamphenicol. Most of the studied compounds were found effective against bacteria studied and yeast.

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

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.

Synthesis, Structural Characterization and Biological Activity of Novel Cyclohexane-1,3-dione Ligands and Their Metal Complexes

Some new Zn(II) and Cu(II) complexes [Cu(L1)(OAc)2]∙H2O, [Cu(L1)(NO3)H2O]∙NO3∙3.5H2O, [Zn(L1)(NO3)2]∙4.5H2O, [Zn(L1)(OAc)2(H2O)2]∙3H2O, [Cu2(L2)(OAc)4]∙2H2O∙2DMF, [Cu(L2)2]∙2NO3∙1.5DMF∙H2O, [Zn(L2)2(NO3)2]∙DMF and [Zn2(L2)(OAc)4(H2O)4]∙5H2O; L1 = 2-[2-(2-methoxyphenyl)hydrazono]cyclohexane-1,3-dione and L2 = 2-[2-(3-nitrophenyl)hydrazono]cyclohexane-1,3-dione were synthesized and characterized by IR, 1H-NMR,13C-NMR and ultraviolet (UV-Vis.) spectroscopy, elemental analysis, magnetic susceptibility, mass spectrometry and thermogravimetry-differential thermal analysis (TGA-DTA). The synthesized ligands and their complexes were tested for antibacterial activity against Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, and Salmonella typhimurium CCM 583. Some of complexes showed medium-level antibacterial activity against the test bacteria compared with ampicillin.

Ethyl 2-[(2-hy­droxy­benzyl­idene)amino]-6-methyl-4,5,6,7-tetra­hydro­thieno[2,3-c]pyridine-3-carboxyl­ate

The title compound, C18H20N2O3S, exists as the phenol–imine form in the crystal and there are bifurcated intramolecular O—H⋯(N/O) hydrogen bonds present. The conformation about the C=N bond is anti (1E); the C=N imine bond length is 1.287 (4) Å and the C=N—C angle is 122.5 (3)°. In the tetrahydrothienopyridine moiety, the six-membered ring has a flattened-boat conformation. In the crystal, molecules are stacked nearly parallel to (110) and a weak C—H⋯π interaction is observed. The carbonyl O atom is disordered over two positions and was refined with a fixed occupancy ratio of 0.7:0.3.

4-[2-(2,2-Dimethyl-4,6-dioxo-1,3-dioxan-5-yl-idene)hydrazin-1-yl]benzo-nitrile.

In the title compound, C(13)H(11)N(3)O(4), the dioxane ring adopts an envelope conformation with the C atom bonded to the dimethyl group in the flap position [deviation = 0.613 (1) Å]. The nitrile group and the attached benzene ring are roughly coplanar [maximum deviation = 0.087 (1) Å]. An intra-molecular N-H⋯O hydrogen bond involving the hydrazinyl group generates an S(6) ring. The N-N and C-N bond lengths indicate that the compound may be a mixture of the azo and hydrazone tautomeric forms but the presence of the N-bound H atom supports the hydrazone form. The crystal structure is stabilized by weak inter-molecular C-H⋯O, C-H⋯N and C-H⋯π inter-actions.