A. H. H. Elghandour

Synthesis, Reactions, and Antiviral Activity of 1-(1H-Pyrazolo[3,4-b]pyridin-5-yl)ethanone and Pyrido[2′,3′:3,4]pyrazolo[5,1-c][1,2,4]triazine Derivatives

1-(3-Amino-6-methyl-4-pyridin-3-yl-1H-pyrazolo[3,4-b]pyridin-5-yl)ethanone (3) was obtained in very pure state and used as a good starting material for the present study. It diazotized to give the corresponding diazonium salt 9 and also reacted with phenyl isothiocyanate to give the corresponding thiourea derivative 4. Compound 4 was used for the preparation of thiazole derivatives 5–8 via the reaction with active halogen-containing compounds. On the other hand, compound 9 coupled with several active –CH2- containing compounds to afford the corresponding triazine derivatives 10–17. Considering the data from IR, 1 H NMR, mass spectra, and elemental analyses, the chemical structures of the newly synthesized heterocyclic compounds were elucidated. Cytotoxicity, anti-HSV1, and anti-HAV-MBB activity were evaluated for the newly synthesized heterocyclic compounds.

Synthesis, Reactions, and Antiviral Activity of 5′-Acetyl-6′-methyl-2′-thioxo-1′,2′-dihydro-3,4′-bipyridine-3′-carbonitrile

Bipyridine-3′0-carbonitrile derivatives 5 reacted with several halogen containing reagents, e.g., 1-chloroacetone, 3-chloropentan-2,4-dione, ethyl chloroacetate, ethyl 2-chloro-3-oxobutanoate, 2-chloroacetamide, chloroacetonitrile, and iodomethane to afford the corresponding thieno[2,3-b]-pyridine derivatives. Considering the data of IR, 1H NMR, mass spectra and elemental analysis the chemical structures of the newly synthesized heterocyclic compounds elucidated. Cytotoxicity, anti-HSV1, (anti-Herpes Simplex virus type 1) anti-HAV (Hepatitis A virus), and MBB activity were evaluated for the newly synthesized heterocyclic compounds.

Synthesis, Characterization, and Antiviral Activities of Pyridopyrazolotriazines

A pyrazolo[3,4-b]pyridine-5-carbonitrile derivative was diazotized to give the corresponding diazonium salt, which was used as a good synthon to synthesize pyrido[2′,3′:3,4]pyrazolo[5,1-c]triazines via its coupling with several active hydrogen-containing reagents, e.g., 2,4-pentandione, ethyl 3-oxo-butanoate, diethylmalonate, malononitrile, 2-cyanoethanethioamide, and ethyl cyanoacetate. Also, it reacted with phenylisothiocyanate to afford the corresponding pyrazolo[3,4-b]pyridin-3-ylphenylthiourea derivative, which, in turn, was used for further chemical transformations. The data of IR, 1 H NMR, mass spectra, and chemical analyses elucidated the structures of all newly synthesized heterocyclic compounds. Cytotoxicity, anti–HSV1 and anti–HAV, and MBB activities were evaluated for all newly synthesized heterocyclic compounds.

Metal chelates of some 1-substituted-3-thiazole-2-ylthioureas

Abstract The Co, Ni, Cu, Pd and Hg complexes of 1-substituted-3-thiazole-2-ylthiourea have been prepared and characterized.

Synthesis, Reactions, and Antiviral Activity of 6′-Amino-2′-thioxo-1′,2′-dihydro-3,4′-bipyridine-3′,5′-dicarbonitrile

Nicotinaldehyde 1 reacted with 2-cyanoethanethioamide 2to give 2-cyano-3-pyridin-3-ylprop-2-enethioamide 3, which reacted with a second mole of 2to give the corresponding 6′-amino-2′-thioxo-1′,2′-dihydro-3,4′-bipyridine-3′,5′-dicarbonitrile 6. The synthetic potentiality of compound 6 was investigated via its reaction with active halogen-containing reagents, e.g., chloroacetone, 2-chloro-3-oxobutanoate, 2-chloroacetamide, chloroaceto-nitrile, and ethyl chloroacetate, to afford the corresponding thieno[2,3-b]-pyridine derivatives. Structure elucidation of all newly synthesized heterocyclic compounds was based on the data of elemental analyses, and IR, 1 H NMR, as well as mass spectra. Cytotoxicity, anti–HSV1, anti–HAV, and MBB activities were evaluated for all newly synthesized heterocyclic compounds.

UTILITY OF HYDRAZIDOYL HALIDES IN HETEROCYCLES: A NEW ROUTE FOR THE SYNTHESIS OF ALKYLMERCAPTOHETEROCYCLIC COMPOUNDS

Abstract The reaction of hydrazidoyl chloride (I) with ethyl mercaptan afforded the thioether derivative II. Compound II was converted to the pyridazine derivative III by fusion with ethyl cyanoacetate. Compound III was converted to the corresponding dioxide derivative IV. Compound III was utilized to synthesize a variety of heterocyclic compounds such as phthalazine and thieno[2,3-d] pyridazine derivatives, VIIIa-e and XI, respectively. Compound XI underwent chemical transformations to afford several new heterocyclic compounds. All structures were established on the basis of elemental analyses and spectral data.

Structural Studies of Metal complexes with a Thiosemicarbazide Derivative

Abstract 1-Cyanoacety1-4-cinnamoylthiosemicarbazide and its complexes of the bivalent metal ions Cu(II), Ni(II), Co(II), Pb(II) and Hg(II) have been synthesised and characterized. Probable structures for the complex compounds have been proposed on the basis of elemental analyses, conductometric, spectral and magnetic susceptibility data. The acid dissociation constant of the ligand was determined potentiometrically.

Binary and ternary complexes of sulphamethoxazole

SummaryThe complex formation equilibria involved in the binary and ternary systemsM(II)-sulpha andM(II)-phen-sulpha were investigated by potentiometric titrations at 25°C and a ionic strength of 0.1N NaNO3 (M = Cu, Ni, Co, Zn;sulpha = sulphamethoxazole;phen = phenanthroline). The stability constants of the binary and ternary complexes follow the order ofIrving andWilliam. The formation of the ternary complex is discussed in terms of the binary species. The mode of chelation was ascertained by conductivity measurements.ZusammenfassungDie an den binären und ternären SystemenM(II)-sulpha undM(II)-phen-sulpha (M = Cu, Ni, Co, Zn;sulpha = Sulphamethoxazol;phen = Phenanthrolin) beteiligten Komplexbildungsgleichgewichte wurden bei 25°C und einer Ionenstärke von 0.1N NaNO3 mittels potentiometrischer Titration untersucht. Die Stabilitätskonstanten der binären und ternären Komplexe gehorchen der Reihenfolge vonIrving undWilliam. Die Bildung der ternären Komplexe wird auf der Basis der binären Spezies diskutiert. Die Art der Chelatbildung wurde durch Leitfähigkeitsmessungen ermittelt.

ACTIVATED NITRILES IN HETEROCYCLIC SYNTHESIS: NOVEL SYNTHESIS OF PYRIDINE, BENZO[1,4]THIAZINE AND BENZO [1,3]THIAZOLE DERIVATIVES

Abstract A novel synthesis of pyridine. benzo[1,4]thiazine and benzo[1,3]thiazole derivatives utilizing o-aminobenzenethiol and α,β-unsaturated nitriles as starting components is reported.