Omer Tahir Gunkara

Synthesis of new pyrazolone dyes

New azo- and bisazo-5-pyrazolone dyes have been synthesised by azo coupling of various arylamines and aryl diamines with 5-pyrazolones: 1-methyl-3-phenyl-1H-pyrazol-5(4H)-one, 1-(4-chlorophenyl)-3-isopropyl-1H-pyrazol-5(4H)-one and 3-isopropyl-1-(4-methoxyphenyl)-1H-pyrazol-5(4H)-one, respectively. All new synthesised dyes have been characterised by FTIR, 1H, 13C NMR and UV-Vis spectral studies with GC/MS and LC/MS analyses. FTIR and 1H NMR studies confirmed the existence of azo- and hydrazo-tautomeric forms of the dyes in the solid and liquid states, respectively.

Synthesis of new aryl(hetaryl)-substituted tandospirone analogues with potential anxiolytic activity via reductive Heck type hydroarylations

Tandospirone (I), developed as an anxiolytic drug, is an aryl-piperazine compound that binds to both 5-HT1A and dopamine D4 receptors. Palladium-catalysed hydroarylation reactions of tandospirone analogues containing an oxygen bridge and 3-(trifluoromethyl)phenyl or 2,3-dichlorophenyl groups were studied in order to find a new stereoselective access to a series of new exo-aryl(hetaryl)-substituted derivatives with potential biological activity.

Aryl- and Heteroaryl Substituted Tandospirones as Possible Antidepressant Drugs

Nowadays, heterocyclic compounds which have a nitrogen atom on the structure, such as pharmacological products, pesticides and antimicrobials can be demonstrated by biologically-active groups that serve the pharmaceutical industry and they are still important in this field. Various cyclization reactions form the basis of the literature on the syntheses of heterocyclic compounds. NArylpiperazines are a class of heterocyclic compounds that play an important role in organic synthesis and are generally found as fragments in receptor ligands and natural products. They have been used extensively as reactive species for building chemical diversity. Arylpiperazines are also found in many pharmacologically-active molecules. Our research group has published numerous papers over the last two years on the synthesis of potentially bioactive tandospirone analogues which have a piperazine group by reductive Heck reactions. We also reported some important isoxazoline derivatives by 1,3-dipolar cycloadditions. Our work continued with potentially pharmacologically-active tandospirone analogues which have an exo-ring in the tricyclic system with an oxygen bridge and containing a 3-(trifluoromethyl)phenyl and 2,3-dichlorophenyl group on the aromatic ring.

Synthesis of New Tandospirone Analogues Carrying 1-(3-(Trifluoromethyl)phenyl)piperazine

Abstract New tandospirone analogues containing a 1-[3-(trifluoromethyl)phenyl]piperazine (TFMPP) moiety have been synthesized by hydroarylation reactions with Pd(OAc)2. The perhydroisoindole derivatives were obtained by the reaction of reduced starting material with aryl-(heteroaryl) iodides under the same conditions. Spiro-1,3-indandionolylpyrrolidine derivatives having an array of stereocenters are reported. GRAPHICAL ABSTRACT

Synthesis of Arylpiperazine Substituted Bisindolylmethanes as Possible Pharmacologically Active New Compounds

Nitrogen containing heterocyclic rings with a piperazine group are valuable target compounds in medicinal chemistry due to their diversified biological activities. In recent years, many organocatalytic/metal free synthetic pathways towards bisindolylmethanes have been reported. In the present work, we combined bisindolylmethanes with arylpiperazines using hydrophobic moiety (alkyl chain) to obtain heterocycles that can be evaluated in pharmacologically and may be more active than the already active bisindolylmethane alkaloids.