Synthesis,characterization, and DNA-binding of a four-coordinate cobalt(II) complex with 1,3-bis(1-ethylbenzimidazol-2-yl)-2-oxopropane

A new four-coordinate cobalt(II) complex with 1,3-bis(1-ethylbenzimidazol-2-yl)-2-oxopropane (Etobb), Co(Etobb)Cl₂, has been synthesized and characterized by elemental analysis, electrical conductivities, infrared, and UV-Vis spectral measurements. The crystal structure has been determined by single-crystal X-ray diffraction. Cobalt(II) is a distorted tetrahedral geometry, surrounded by two nitrogens from Etobb and two chlorides. DNA-binding properties of Etobb and its Co(II) complex have been investigated by electronic absorption, fluorescence, and viscosity measurements. The experimental results suggest that the ligand and its Co(II) complex bind to DNA via intercalation, and the binding affinity of the Co(II) complex to DNA is greater than Etobb.     

Synthesis and spectral studies on heterobimetallic complexes of manganese and ruthenium derived from N-(2-hydroxynaphthalen-1-yl)methylenebenzoylhydrazide

The complex [Mn^IV(napbh)₂] (napbhH₂ = N-(2-hydroxynaphthalen-1-yl)methylenebenzoylhydrazide) reacts with activated ruthenium(III) chloride in methanol in 1 : 1.2 molar ratio under reflux, giving heterobimetallic complexes, [Mn^IV(napbh)₂Ru^IIICl₃(H₂O)] · [Ru^III(napbhH)Cl₂(H₂O)] reacts with Mn(OAc)₂·4H₂O in methanol in 1 : 1.2 molar ratio under reflux to give [Ru^III(napbhH)Cl₂(H₂O)Mn^II(OAc)₂]. Replacement of aquo in these heterobimetallic complexes has been observed when the reactions are carried out in the presence of pyridine (py), 3-picoline (3-pic), or 4-picoline (4-pic). The molar conductances for these complexes in DMF indicates 1 : 1 electrolytes. Magnetic moment values suggest that these heterobimetallic complexes contain Mn^IV and Ru^III or Ru^III and Mn^II in the same structural unit. Electronic spectral studies suggest six coordinate metal ions. IR spectra reveal that the napbhH₂ ligand coordinates in its enol form to Mn^IV and bridges to Ru^III and in the keto form to Ru^III and bridging to Mn^II.     

Synthesis of N-Substituted Derivatives of (5-Amino-2-methyl-1H-indol-3-yl)acetic Acid

A method has been developed for obtaining indole compounds containing an amino group in the benzene ring by the indolization of ethyl levulinate p-acetaminophenylhydrazone. A series of derivatives of (5-amino-2-methyl-1H-indol-3-yl)acetic acid at the 5-amino group has been synthesized.     

Synthesis of 2-Trihalomethyl-3,4-dihydrothieno[2,3-d]pyrimidin-4-ones

At room temperature, N-(1-chloro-2,2,2-trihaloethylidene)-O-methyl urethanes react with 2-aminothiophenes to form N-(2-thienyl)-N'-(methoxycarbonyl)trihaloacetamidines, which when heated in boiling toluene undergo ring closure to form 2-trihalomethyl-3,4-dihydrothieno[2,3-d]pyrimidin-4-ones.     

Synthesis of 2-oxazolidinones from (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol

A series of isomeric 2-oxazolidinones has been synthesized from (1S, 2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 579–584, April, 2006.     

2-(2-Thiazolylazo)-pcresol (TAC) as a reagent for the spectrophotometric determination of titanium (IV)

The reaction between titanium(IV) and 2-(2-thiazolylazo)-p-cresol-(TAC) in aqueous methanol media at apparent pH 4.0–5.6 results in a intensely coloured complex that is stable for at least 2 h. The combining ratio is 1 1 cation TAC. Beer's law is obeyed up to 5.0 g/ml titanium(IV) at 580 nm. The apparent molar absorptivity at 580 nm is 9.82.10³ l.mole^–1.cm^–1 and the detection limit obtained was 5 ng/ml titanium (IV). A spectrophotometric method for the simultaneous determination of titanium and iron with TAC is proposed.     

Synthesis of N-(7-methyl-5-oxo-5H-1M,3,4-thiadiazolo[3,2-a]pyrimidin-2-yl)-N'-phenylhydrazine and its reaction with bromine

Synthesis of the title compound is described and its reaction with bromine is studied. This involves oxidation of the hydrazine moiety and sequential bromination of the benzene and thiadiazolopyrimidine nuclei to give, respectively, 2-(4-bromophenylazo)-7-methyl-5-oxo-5H-1, 3,4-thiadiazolo[3,2-a]pyrimidine and 6-bromo-2-(4-bromophenylazo)-7-methyl-5-oxo-5H-1, 3,4-thiadiazolo[3,2-a]pyrimidine.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 219–220, January, 1993.     

Synthesis of 2-(2-hydroxyaroylmethylene)hexahydropyrimidines from 2-trichloromethylchromones and trimethylenediamine

The reactions of 2-trichloromethylchromones with trimethylenediamine in ethanol at room temperature afford 2-(2-hydroxyaroylmethylene)hexahydropyrimidines. Under analogous conditions, 2-methylchromone gives a mixture ofN,N′-trimethylenebis[3-amino-1-(2′-hydroxyphenyl)-2-buten-1-one] andN,N′-trimethylenebis(imine) of 2-hydroxyacetophenone. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2140–2143, November, 1999.     

Synthesis of peroxide compounds by the BF3-catalyzed reaction of acetals and enol ethers with H2O2

Aliphatic and alicyclic gem-bis-hydroperoxides and their derivatives, bis(1-hydroperoxycycloalkyl) and bis(1-hydroperoxyalkyl) peroxides, dispiro- and tetraalkyl-1,2,4,5-tetroxanes were synthesized by the reaction of aliphatic and alicyclic acetals and enol ethers with H₂O₂ in the presence of BF₃ in anhydrous Et₂O.     

Cyanamides in cyclization reactions with anthranilates, 2-aminophenyl ketones, and methyl 2-(3-oxopiperazin-2-yl)acetate

Cyclization of aryl-, aroyl-, and (4,6-dimethylpyrimidin-2-yl)cyanamides with methyl anthranilates, 2-aminophenyl ketones, and methyl 2-(3-oxopiperazin-2-yl)acetate leads to 2-amino-3,4-dihydroquinazolin-4-one, 2-aminoquinazoline, and 6-amino-1,3,4,8,9,9a-hexahydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione derivatives, respectively. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 164–170, January, 2008.     

Synthesis and Application of Disperse Dyes Based on 2-Aminothiazole Derivatives

A series of novel monoazo disperse dyes based on 2-amino-5-nitro-4-(p-nitrophenyl)thiazole were prepared using various N,N-dialkylaniline derivatives as the coupling components. The spectral properties in the IR and visible range of the dyes were investigated. The dyeing performance of these dyes was assessed on nylon fabric. These dyes were found to give a wide range of color shades from reddish brown to indigo with excellent brightness, levelness, and depth on nylon fabric. The dyed fabric showed fairly good light fastness, good to excellent fastness to wash and perspiration, and excellent fastness to sublimation. The dyebath exhaustion and fixation of the dyes on nylon were found to be very good and acceptable.     

Photochemical and thermal rearrangements of 2-arylamino-1-(4-tert-butylphenoxy)-9,10-anthraquinones

Photochemical transformations of 2-arylamino-1-(4-tert-butylphenoxy)-9,10-anthraquinones involve migration of thetert-butylphenyl group either to theperi-located carbonyl oxygen to give 2-arylamino-9-(4-tert-butylphenoxy)-1,10-anthraquinones or to the nitrogen atom to give 2-aryl(4-tert-butylphenyl)amino-1-hydroxy-9,10-anthraquinones (typical products of the Smiles rearrangement). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2519–2522, December, 1998.     

Synthesis of fused systems containing an angular nitrogen atom from substituted 2-benzyl-4-hydrazinopyridimines

The condensation of substituted 2-benzyl-4-hydrazinopyrimidines with phenylpyruvic acid gave the corresponding hydrazones, which cyclize upon the action of POCl, to give derivatives of pyrimido[6,1-c][1,2,4]-triazine. The substituted 2-benzylpyrimidinylhydrazides of some carboxylic acids react with POCl, to give 1,2,4-triazolo[4,3-c]pyrimidines. The reaction of 7-benzyl-5-methyl-l-phenyl-1,2,4-triazolo[2,3-c]pyrimidine with sodium ethylate leads to rearrangement and formation of 7-benzyl-5-methyl-2-phenyl-1,2,4-triazolo[2,3-c]pyrimidine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 225–229, February, 2000.     

Complexes of cobalt(2+) chloride with hydrochlorides of N-(1,2,4-triazol-5-yl)- and N-(tetrazol-5-yl)benzamidines

We have synthesized complex compounds of Co(2+) chloride with hydrochlorides of N-(1,2,4-triazol-5-yl)benzamidine and N-(tetrazol-5-yl)benzamidine. According to magnetochemistry and electron spectroscopy data, the ligands are coordinated in a bidentate fashion with the N atom of the amidine group and the N atom of the heterocycle with formation of the tetrahedral chromophore CoN₂Cl₂.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2311–2315, October, 1992.     

Nickel complexes bearing 2-(1H-benzimidazol-2-yl)-phenoxy ligands: Synthesis, characterization and ethylene oligomerization

A series of 2-(1H-benzimidazol-2-yl)-phenols and their nickel complexes have been synthesized and characterized by elemental and spectroscopic analysis. The molecular structures of ligand L4 and complex C5 were confirmed by X-ray diffraction analysis. X-ray crystallographic analysis revealed that complex C5 has a six-coordinated distorted octahedral geometry. Upon activation with Et₂AlCl, these nickel(II) complexes showed good activity for ethylene oligomerization. When PPh₃ was added as an auxiliary ligand to the catalytic system, an increased activity as high as 1.60 × 10⁷ g mol⁻¹ (Ni) h⁻¹ was observed. The ligand environment and reaction conditions remarkably affected the catalytic behavior of these nickel complexes.     

Synthesis and crystal structure of complex of Ce(NO_3)_3 with N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl-pyridin-2-yl) hydrazone

Rare earth complexes with organic ligands have been used as luminescence-material usually. Except their luminescent property, the complexes of trivalent lanthanide ions have low toxicity and powerful para-magnetic properties[1,2], so the lanthanide complexes are associated with important biological uses as diag-nostic tools and medicines[36]. Recently, there are some reports on Ce(III) complexes, some of which show anti-cancer activities[7]. S- tetrazines can be used as poly-dentate chelatin…     

Synthesis of Functionally Substituted Pyrrolo[2,3-g]- and Pyrrolo[3,2-f]quinolines from 5-Amino-2-phenyl- and 5-Amino-1-methyl-2-phenylindoles

The behavior of 5-amino-2-phenyl- and 5-amino-1-methyl-2-phenylindoles in reactions with acetoacetic, trifluoroacetoacetic, and ethoxymethylenemalonic esters, leading to the preparation of pyrrolo[2,3-g]- and pyrrolo[3,2-f]quinolines with functional substituents has been studied.