Cyanoacetic acid hydrazide: An efficient access for the synthesis of multi-functional azine and azole derivatives

Herein, the synthesis of nitrogen-containing heterocyclic scaffolds from heterocyclization of cyanoacetic acid hydrazide derivatives is described. Thiosemicarbazide derivative 1a undergoes base-mediated cyclization producing pyrazole derivative of type 2 . The triazolopyridine 5 was obtained by double cyclization of 1a and benzylidene malononitrile. Compound 1b condensed with ethyl chloroformate to furnish pyrazolooxazine 8 . Compound 1b was added to benzoyl isothiocyanate under thermal condition to form oxadiazine derivative 10 while, keeping the above reactant under room temperature to form acyclic derivative 11 . Using CS₂ as a cyclizing agent for compound 1b yielded pyrazole derivative 13 . Treatment of 1b with I₂ resulted in oxidative cyclization producing pyridazine derivative 14 . Compound 1c cyclized with benzoyl isothiocyanate forming triazolothiazine derivative 18 . While using cinnamoyl isothiocyanate, the acyclic product 22 was obtained. Compound 1c was condensed with formaldehyde leading to oxadiazole derivative 25 .     

Variational treatment of continuum orbitals for Auger electrons emitted from neon

A variational method is applied to obtain the wave function of the continuum Auger electron emitted from an ionized neon atom. The trial function is taken to depend on several adjustable parameters, and the wave function of the electrons in different orbitals, such that all possible virtual states of the quantum mechanical system composed of the Auger electron and the ion are represented. The continuum wave function is improved iteratively by increasing the number of terms.Auger transition rates are then calculated applying the angular momentum average scheme, and are compared with other theoretical and experimental results. Agreement with the latest experiment is achieved.     

Chelating Behaviour of Substituted 3-4 Aryl-Hydrazo-Pentane-2, 4-Dione: Part VI. Potentiometric and Infrared Studies of the Ligands and Their Divalent Metal Complexes

The dissociation constants of 3-phenylhydrazo-pentane-2, 4-dione and its o-, m-, p-carboxy derivatives, and the stability constants of complexes of divalent metal ions with the o-carboxy derivative are determined by pH-metric method. The ir-spectra of the ligands and some divalent metal complexes with the o-derivative are discussed.     

Electron Paramagnetic Resonance and Mössbauer Studies of Fe3+ Ions in the Fe2O3 [dbnd] MoO3 System

The electron paramagnetic resonance (EPR) and Mössbauer spectra of ironmolybdenum mixed oxides system have been investigated. Both EPR and Mössbauer measurements revealed the formation of ferric molybdate, Fe₂ (MoO₄)₃ and the existence of two different Fe³⁺ species. The EPR spectra of Fe₂ (MoO₄)₃, show two resonance lines of Fe³⁺ ions indicating that a strong exchange interaction is dominates in pure iron molybdate. Mösbauer measurements revealed that the isomer shift (I. S) increases with increasing the iron content. A maximum of quadrupole splitting (Q. S) is observed at the stoichiometric concentration corresponding to the formation of Fe₂ (MoO₄)₃. The effect of a catalytaic dehydration process on the redox behaviour of Fe³⁺ located in iron molybdate frame work is investigated. Results indicate that the catalytaic dehydration of 2-proppanol over this catalyst reduces Fe³⁺ ions to Fe²⁺ leading to the formation of the inactive phase FeMoO₄. the essential role of oxygen, in the alcohol gas feed, in regeneration the activity of the catalysts was demonstrated.     

Mössbauer Study of Some Iron Organo-Metallic Complexes

Mössbauer absorption spectra were obtained for ferric complexes of urea and thiourea derivatives with dibasic acids. The complexes were prepared in the two ratios 1:1 and 2:1 metal to ligand. The Mössbauer parameters were analysed inconsistent with the structural data obtained from I.R. spectra. It was found that changing the metal -ligand ratio has nearly no effect on both the isomer shift and quadrupole splitting values.     

Regioselective Synthesis of Substituted Triazolium Salts via 1,3-Dipolar Cycloaddition Reactions

The regioselectivity of 1,3-dipolar cycloaddition reactions of 1-aza-2-azoniaallene salts with ,-unsaturated nitriles such as acrylonitrile or cyclohexylidene acetonitrile afforded only 1,2,4-triazolium salts via addition to the nitrile group, while the other expected pyrazolium salts were not observed. Moreover, 1-aza-2-azonia-allene salts reacted with other competitive systems such as -iminonitrile derivatives yielding only triazolium salts via addition to the nitrile and not to the imino group. Treatment of cumulene with 3-pyridylnitrile afforded the pyridinium salt. However, 2,3-dimethyl-5-(2,6-dimethoxyphenyl)-[1,2,4]triazole could be prepared from cumulene and 2,6-dimethoxybenzonitrile. Some reactions of nitriles with 1-aza-2-azonia-allene salts prepared from 1,2,3-indantrione and 9-acetylphenanthrene are discussed.     

On Condensation Reactions of Aceanthrene Quinone: Novel Heterocycles

Summary.  It was found that aceanthrene quinone can be condensed with ethylenediamine, 1,2-diaminobenzene, 4-nitro-1,2-diaminobenzene, 1,2-diaminoanthrene quinone, and 4,5,6-triaminopyrimidine derivatives to give aceanthryleno[1,2-b]pyrazine and aceanthryleno[1,2-g]pteridine derivatives. Condensation of aceanthrene quinone with 2-aminoguanidine, semicarbazide, and thiosemicarbazide yielded aceanthryleno[1,2-e]triazines, condensation with 6-hydrazinopyrimidine derivatives gave 3,4-aceanthrylenopyrimido[4,5-c]pyridazines. Reaction of aceanthrene quinone with 2-cyanoethanoic acid hydrazide afforded 10,11-dihydro-10-oxo-aceanthryleno[1,2-c]pyridazine-9-carbonitrile. Treatment of aceanthrene quinone with malononitrile and hydrazine hydrate resulted in 10-aminoaceanthryleno[1,2-c]pyridazine-9-carbonitrile. The antibacterial effects of the prepared compounds were tested. Three of the compounds were tested against 60 cancer types. Received May 6, 2001. Accepted June 5, 2001     

On The Chemistry of Cinnoline IV [1]. Synthesis and Reactions of (4-Aminocinnolin-3-yl)-aryl-methanones

Summary.  The synthesis of a series of disubstituted (4-aminocinnolin-3-yl)-aryl-methanones from aryl-hydrazonomalononitrile in a one-step procedure is described. Cyclocondensation of (4-amino-6,8-dimethyl-cinnolin-3-yl)-phenyl-methanone with malononitrile, diethylmalonate, and dimethylacetamide-dimethylacetal gave the corresponding pyrido[3,2-c]cinnoline derivatives. Treatment of (4-amino-6,8-dimethyl-cinnolin-3-yl)-phenyl-methanone with triethyl-orthoacetate under reflux readily afforded the corresponding imidoester which underwent cyclization to a pyrido[3,2-c]cinnoline derivative. This starting compound could also be annelated to the corresponding 1,2-dihydro-4-aryl-2-oxo-pyrido[3,2-c]cinnoline derivatives via the (4-acetamidocinnolin-3-yl)-aryl-methanones. Chemical and spectroscopic evidences for the structures of the new compounds are presented. The effect of three of the compounds against sixty cancer types was tested. Received November 27, 2000. Accepted December 4, 2000