Mehtap Gökçe

Synthesis and analgesic and anti-inflammatory activities 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(p-substituted/nonsubstituted benzal)hydrazone derivatives.

In this study new 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(p-substituted benzal)hydrazone V derivatives were synthesized as analgesic and anti-inflammatory agents. The structures of compounds were elucidated by spectral and elemental analysis. Compounds Va, Vb and Vc were exhibited more potent analgesic activity than ASA. Also these derivatives demonstrated anti-inflammatory activity as well as standard compound indomethacin. Side effects of the compounds were examined on gastric mucosa. None of the compounds showed gastric ulcerogenic effect compared with reference nonsteroidal anti-inflammatory drugs (NSAIDs). On the basis of available data, the structure-activity relationship of V derivatives was also discussed.

Synthesis and antinociceptive activity of 6-substituted-3-pyridazinone derivatives.

A series of 3-pyridazinones carrying morpholino, arylpiperidino and arylpiperazino moiety in the position 6 IIa-g were synthesized and evaluated for antinociceptive activity. In the modified Koster test in mice 4-(4-fluorophenyl) piperazine, IIf, was found the most active compound. All the compounds except IId were more active than aspirin in the antinociceptive activity test.

Synthesis of novel 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(substituted/-nonsubstituted benzal)hydrazone derivatives and acetylcholinesterase and butyrylcholinesterase inhibitory activities in vitro.

In this study thirteen 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(substituted/nonsubstituted benzal)hydrazone V derivatives were synthesized as acetylcholinesterase and butyrylcholinesterase inhibitors. Ten of the synthesized compounds were synthesized for the first time in this study and the rest of them had been synthesized in a previous study. The structures of compounds V were elucidated by IR, 1H-NMR and MASS spectra. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChe) inhibitory activities of V derivatives were measured using Ellmans method. While some of the 6-substituted-3(2H)-pyridazinone-2-propyl-3-(substituted/-nonsubstituted benzal)hydrazone V derivatives exhibited significant AChE inhibitory activity, none of the compoundsshowed BChE inhibitory activity. Theseresults indicate that V derivatives were AChE inhibitors with AChE/ BChE selectivity.

Synthesis and anticonvulsant activity of 5-chloro-2(3H)-benzoxazolinone-3-acetyl-2-(o/p-substituted benzal) hydrazone derivatives.

It is well known that some hydrazone derivatives of both 2-oxobenzoxazoline and 2-oxobenzothiazoline exhibit potent anticonvulsant activity. In order to investigate the effects of structural modifications on the biological properties, 14 new hydrazones of 5-chloro-2(3H)-benzox-azolinone-3-acetyl hydrazide were synthesized. The chemical structures of the synthesized compounds were established by IR, 1H-NMR spectral analyses and elementary analyses. The anticonvulsant activities of the title compounds were tested by the penthylenetetrazole induced seizure test. 5-Chloro-2(3H)-benz-oxazolinone-3-acetyl-2-(o-methoxy-benzaldehyde)-hydrazone 4d, 5-chloro-2(3H)-benzoxazolinone-3-acetyl-2-(o-methybenzaldehyde)-hydrazone 4g, 5-chloro-2(3H)-benzoxazolinone-3-acetyl-2-(p-methylbenzaldehyde)-hydrazone 4h, 5-chloro-2(3H)-benzoxazolino-ne-3-acetyl-2-(p-nitrobenzaldehyde)-hydrazone 4m, and 5-chloro-2(3H)-benzox-azolinone-3-acetyl-2-(p-dimethylaminobenzaldehyde)-hydrazone 4n were found more active than phenytoin (CAS 57-41-0) in the tests.

Synthesis and antimicrobial, acetylcholinesterase and butyrylcholinesterase inhibitory activities of novel ester and hydrazide derivatives of 3(2H)-pyridazinone

In the current study, some novel ethyl 6- [(substituted-phenylpiperazine]-3(2H)-pyridazinone-2-yl propionate III and 6-[(substituted-phenylpiperazine]-3(2H)-pyridazinone-2-yl propionohydrazide IV derivatives were synthesized as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. The structures of these new pyridazinone derivatives were confirmed by their IR, 1H-NMR spectra and elementary analysis. 6-Substituted-3(2H)-pyridazinone-2-yl propionate IIIa-e derivatives showed significant inhibitory activity against AChE and BChE. 6-[4-(3-Trifluoromethylphenyl)piperazine]-3(2H)-pyridazinone-2-yl propionate IIIe has been found to be the most active compound in terms of inhibition of either AChE or BChE. Compound IIIe exhibited inhibitory activity close to that of galantamine (CAS 357-70-0) and did not show any selectivity between the two enzymes. Also the antimicrobial activities of III and IV derivatives have been evaluated. All III and IV derivatives exhibited poor antibacterial activities but moderate antifungal activities.

Synthesis and analgesic and anti-inflammatory activity of 6-phenyl/(4-methylphenyl)-3(2H)-pyridazinon-2-propionamide derivatives.

For reducing gastrointestinal toxicity associated with non-steroidal anti-inflammatory drugs (NSAIDs) a variety of 6-phenyl/(4-methylphenyl)-3(2H)-pyridazinon-2-propionamide were synthesized. The structures of these new pyridazinone derivatives were confirmed by their IR, 1H-NMR spectra and elementary analysis. All the new compounds were tested in vivo for their analgesic and anti-inflammatory activities. The analgesic activity of the test compounds was determined by phenylbenzoquinone-induced writhing assay and the anti-inflammatory activity was evaluated by the carrageenan-induced rat paw edema model. 6-Phenyl-3(2H)-pyridazinon-2-yl-[4-(4-fluorophenyl)piperazinyl] propanamide IVa-3 was the most active one among the synthesized compounds. Also this compound exhibited most potent anti-inflammatory activity. Acetylsalicylic acid and indometacin were used as reference drugs. Adverse effects of the compounds were examined on gastric mucosa. None of the compounds showed gastric ulcerogenic effect compared with the reference NSAIDs.

Synthesis and analgesic and anti-inflammatory activity of ethyl (6-substituted-3 (2H)-pyridazinone-2-yl)acetate derivatives.

A number of 6-substituted-3(2H)-pyridazinones and the corresponding methyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate derivatives carrying the arylpiperazinyl structure present in potent antinociceptive agents reported in the literature were synthesized. As part of a programme a series of diverse arylpiperazine derivatives of ethyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate were prepared and tested for their in vivo analgesic and anti-inflammatory activity by using p-benzoquinone-induced writhing test and carrageenan-induced hind paw edema model, respectively. Side effects of the compounds were examined on gastric mucosa. None of the compounds showed gastric ulcerogenic effect compared with reference non-steroidal anti-inflammatory drugs (NSAIDs). On the basis of available data, the structure-activity relationship in the series of ethyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate derivatives was also discussed. When compared to parent 6-substituted-3(2H)-pyridazinones, the new ester derivatives, for example ethyl (6-4-[(2-fluoro)phenyl]piperazine-3(2H)-pyridazinone-2-yl)acetate exhibited better analgesic and anti-inflammatory activity and a lower ulcerogenic effect.

3-Chloro-6-[4-(2-pyrid-yl)piperazin-1-yl]pyridazine.

In the title compound, C13H14ClN5, the piperazine ring adopts a chair conformation and the dihedral angle between the aromatic rings is 13.91 (7)°. The crystal structure is stabilized by weak intermolecular C—H⋯N hydrogen-bond interactions.

3-Chloro-6-{4-[3-(trifluoro-meth-yl)phen-yl]piperazin-1-yl}pyridazine.

The title compound, C15H14ClF3N4, was synthesized from 3,6-dichloropyridazine and 1-[3-(trifluoromethyl)phenyl]piperazine. The piperazine ring is flanked by 3-chloropyridazine and 3-trifluoromethylphenyl rings and adopts a chair conformation, whereas the 3-chloropyridazine and 3-trifluoromethylphenyl rings are planar, with maximum deviations of 0.0069 (13) and 0.0133 (14) Å, respectively. The crystal structure is stabilized by weak intermolecular C—H⋯N hydrogen-bond interactions.