Nuket Ocal

Synthesis of New Pyrazolothiazole Derivatives from 4-Thiazolidinones

The synthesis of new 2,3,5,6-aryl substituted tetrahydro-2H-pyrazolo[3,4-d]- thiazoles 4a-j as potential biologically active compounds by the cyclocondensation of phenyl hydrazine with new 5-arylidene derivatives 2a-j of 2,3-disubstituted-1,3- thiazolidin-4-ones 1a-e is reported.

Epibatidine Alkaloid Chemistry: 5. Domino-Heck Reactions of Azabicyclic and Tricyclic Systems †

Palladium-catalyzed hydroarylations and additional domino reactions of aza-bicyclic and tricyclic norbornene derivatives were investigated and a series of new epibatidine analogues were synthesized.

The Hydroarylation Reaction—Scope and Limitations

The synthetic potential of stereoselective, palladium-catalyzed hydro(het)arylation reactions of bi-, tri- and tetracyclic (hetero)alkenes in the presence of phospines and arsines as highly efficient ligands was studied. The mechanism of this reductive Heck reaction becomes more complex in the case of benzonorbornenes. Hydroarylation of diazabicyclo-[2.2.1]heptenes provides a stereoselective access to aryldiaminocyclopentanes. Electron-deficient arylpalladium complexes shift the reaction towards the product of a formal 1,2-hydrazidoarylation reaction of 1,3-cyclopentadiene by a stereoselective C-N cleavage. Due to steric reasons, rigid bicyclo[2.2.2]octenes react slower in hydroarylation reactions than the corresponding bicyclo[2.2.1]heptenes. The more flexible bicyclo[4.2.2]decene system already tends to undergo domino-Heck reactions, even under reductive conditions. When a tetracyclic cis-allylcyclopropane is carbopalladated in the presence of formates, the neighboring cyclopropane ring is attacked in the first reported example of a π,σ domino-Heck reaction.

Allylation and Heterocycloaddition Reactions of Aldimines: Furan- and Quinolinecarboxaldehydes

Summary. New derivatives of α-substituted furans were prepared in high yields from easily available α-furfurylidenbenzilamines via nucleophilic C-allylation. The homoallylamines obtained this way were used for the synthesis of some polyfunctional aminobutene derivatives. In addition, 4-thiazolidinones some of which are hetaryl substituted at the 2-position were prepared by the reaction of mercapto acids with quinoline carboxaldehydes and p-phenetidine. All new products were fully characterized.Zusammenfassung. Aus den leicht zugänglichen α-Furfurylidenbenzilaminen wurden durch nucleophile C-Allylierung neue Derivative α-substituierter Furane mit hohen Ausbeuten dargestellt. Die dabei gewonnenen Homoallylamine wurden für die Synthese von polyfunktionalen Aminobutenderivaten eingesetzt. Darüber hinaus wurden durch Reaktion von Merkaptosäuren mit Chinolincarboxaldehyden und p-Phenetidin an der 2-Stelle heterosubstituierte 4-Thiazolidinone gebildet. Alle Produkte wurden entsprechend charakterisiert.

Reductive Heck Reactions of N-Methyl-substituted Tricyclic Imides

The palladium-catalyzed hydroarylation of N-methyl-substituted tricyclic imides was studied in order to find a new stereoselective access to a series of new exo-aryl(hetaryl)-substituted tricyclic N-methylimides.

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.

Sulfur-nitrogen heterocycles from the condensation of pyrazolones and 2-iminothiazolidin-4-ones with phenyl isothiocyanate

The condensation of 2-pyrazolin-5-ones with phenyl isothiocyanate, followed by reaction of the resulting thiolate ions with chloroacetyl chloride, phenacyl bromide, oxalyl chloride, 1,4-dibromo-2,3-butanedione and ethyl chloroformate, resulted in cyclisation to S,N-heterocycles in all cases. 2-Iminothiazolidin-4-ones, with phenyl isothiocyanate and then chloroacetyl chloride or phenacyl bromide, similarly formed 2,4′-bi(thiazolidine)-derived products.

Reactions of the Dianion Obtained by Reductive Metallation of 3,4-Diphenylcinnoline

Summary. The reductive metallation of 3,4-diphenylcinnoline (1) by sodium metal in tetrahydrofuran under an inert atmosphere to the monomeric dianion 2 has been explored, and the nucleophilicity of the disodium adduct towards various protonation, alkylation, and acylation reagents has been investigated. Generally, 2 reacts via its 1,4-positions forming 1,4-dihydro derivatives of 1.Zusammenfassung. Die Herstellung des monomeren Dianions von 3,4-Diphenylcinnolin durch reduzierende Metallierung mit metallischem Natrium in Tetrahydrofuran unter einer inerten Atmosphäre sowie die Nucleophilie dieses Dinatriumaddukts gegenüber verschiedener Protonierungs-, Alkylierungs- und Acylierungsreagenzien wurden untersucht. Das Dianion reagiert durchwegs über die Positionen 1 und 4 zu 1,4-Dihydroderivaten von 3,4-Diphenylcinnolin.

Evaluation of the Antioxidative Properties of N-Acylamino-Substituted Tricyclic Imides

New N-acylamino-substituted tricyclic imides have been screened for scavenging ability against the free radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), chelating activity on ferrous ions, and reductive potential. The results were compared with synthetic antioxidants BHT, BHA, and Trolox. The compounds exhibited different levels of antioxidant activity in all tests.

Thiophene-2-carbaldehyde N-(2,4-dinitrophenyl)-N-methylhydrazone.

Molecules of the title compound, C12H10N4O4S, are linked through intermolecular hydrogen bonds to form a dimeric structure. The crystal structure of the dimer is stabilized by two intermolecular hydrogen bonds of the C-H...O type. The C...O intermolecular contact distance is 3.339(3) A, and the C=N and N-N distances are 1.279(2) and 1.371(7) A, respectively. One O atom of the 2-nitro group is disordered over two sites.