Structure and color of protonated benzimidazolyl formazans

Benzimidazolyl formazans were titrated spectrophotometrically and their base constants were determined. On the basis of quantum mechanical calculations of electron spectra a hypothesis concerning the chelate structure of the unsymmetrical benzimidazolyl formazans is proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 822–826, June, 1985.     

Polyfluorobenzoyl chlorides and isothiocyanates in reactions with CH-reactive benzimidazoles

Reactions of 2-benzoylmethylbenzimidazole with tetra- and pentafluorobenzoyl chlorides afford fluorine-containing 6-benzoyl-7H-benzimidazo[3,2-a]quinolones. 2-Cyanomethyl- or 2-benzoylmethylbenzimidazole reacts with tetra(penta) fluorobenzoyl isothiocyanates to give fluorine containing 1,3-benzothiazinones, which differently behave in reactions with cycloalkylimines.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 720–724, March, 2005.     

Fluorine-containing heterocycles: XVII. (Tetrafluorobrnzoyl)thioureas in the synthesis of fluorine-containing azaheterocycles

Proceeding from (tetrafluorobenzoyl)thioureas fluorine-containing derivatives were synthesized of 1-aryl-2-ethylthioquinazolin-4-one, [1,3]benzothiazin-4-one, and also of thiazolidine and 1H-1,2,4-triazole.     

Fluorocontaining Heterocycles: IX. Derivatives of Imidazo[2,1-b][1,3]benzothiazine

The heating of derivatives of benzimidazole-2-thione and imidazolidine-2-thione with tetra(penta)fluorobenzoyl chlorides in toluene or pyridine gave rise to fluorocontaining derivatives of imidazo[2,1-b][1,3]benzothiazine. The latter were studied in reactions of nucleophilic substitution of fluorine for amino groups.     

Tautomerism of 1,5-dibenzazolylformazans

The structures of new symmetrical and asymmetrical 1,5-dibenzazolylformazans were investigated by IR and electronic spectroscopy. It is shown that 1,5-dibenzimidazolylformazans, regardless of the substituent in the 3 position (methyl, phenyl), display the presence of the tautomeric imino form in solutions. 1,5-Dibenzothiazolylformazans display a high tendency to form chelate forms. The stability of the chelate increases on passing from the 3-methyl to the 3-phenyl derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 699–701, May, 1973.     

Advances in verdazyl chemistry

Russian Chemical Bulletin - The main advances in the synthesis and studies of the properties of new stable heterocyclic verdazyl radicals and verdazyl radical coordination chemistry are reviewed....     

1,2,4-Triazino[5,6,1-i,j]quinolines: a new type of tricyclic analogs of fluoroquinolones

The interaction of C-aryl-substituted amidrazones and S-methylisothiosemicarbazide with 3-ethoxy-2-polyfluorobenzoylacrylates results in corresponding N-(quinolin-1-yl)amidines that undergo conversion into derivatives of 1,2,4-triazino[5,6,1-i,j]quinoline by heating in acetic anhydride.     

The crystal and molecular structure of Ni(II) complex with 1-(2-carboxyphenyl)-3-isopropyl-5-(benzimidazole-2-yl)formazane

The binuclear Ni(II) 1-(2-carboxyphenyl)-3-isopropyl-5-(benzimidazole-2-yl)formazanate (Ni₂L₂ · 2H₂O) (I) was synthesized and its crystal and molecule structures were determined by X-ray diffraction. Crystals I are triclinic: space group P \(\bar 1\), a = 7.4811(11), b = 10.8821(15), c = 11.4168(13) Å, α = 105.690(11) Å, β = 90.537(11) Å, γ = 93.166(11) Å, V = 893.2(2) ų, ρ(calcd.) = 1.581 g/cm³, Z = 1.