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Synthesis, structure, properties and reactivity of stable heterocyclic radicals, verdazyls, are considered. Special attention is focused on metal verdazyl complexes. Major areas of application of such radicals are discussed. The bibliography includes 164 references.

A new synthetic approach to the title compound (IV) is presented which is the key intermediate for various further transformations.

The title compounds (V) are obtained by nucleophilic amination-defluorination reaction of the 6,7-difluoro derivative of 3-amino-2-methyl-3H-quinazolin-4-one (III).

The condensation of 2-methylbenzazines with aromatic aldehydes affords the corresponding (E)-2-styryl-substituted 6,7-difluoroquinolines and -quinoxalines, which exhibit photoluminescence in MeCN solution.

Title compounds are synthesized by condensation of appropriate quinazolinones with aromatic aldehydes or by reaction of benzoxazinones (I) with benzylidenephenylamines.

Review: synthetic approaches, chemical properties, structure and biological activity; 138 refs.

The title compounds are synthesized by the reaction of 2- and 4-hydrazino-substituted quinazolines with aldehydes and subsequent oxidative cyclization or by alkylation of 2-alkylthio-4(3H)-quinazolinones with bromoethanol and ipso-substitution of the alkylthio group.

The survey reviews the data on the synthesis, structure and biological activity of fluoroquinolonecarboxylic acids metal chelates. The influence of metal and ligand nature as well as conditions of the synthesis on the polyhedron type is discussed. The data on interaction between fluoroquinolone metal complexes and DNA are explored.

The reaction of N-(ethoxycarbonyl)methyl substituted ethyl 6,7-difluoro-, 6,7,8-trifluoro- and 5,6,7,8-tetrafluoro-4-oxo-1,4-dihydro-quinoline-3-carboxylates with methyl methacrylate results in the [3 + 2] adducts, hexahydropyrrolo[1,2-a]quinolones, which can be precursors of [a]-fused fluoroquinolones.

New derivatives of fused fluoroquinolones bearing five aromatic rings have been obtained. The 19 F NMR spectra of these pentacyclic fluoroquinolones demonstrate unusual through space 1 H – 19 F and 19 F – 19 F spin–spin interactions with coupling constants 6 J (F, H)=2.0–3.0 Hz, 7 J (F, F)=3.5–4.0 Hz and 9 J (F, H)=3.0–3.5 Hz. Relative reactivities of fluorine atoms in pentacyclic fluoroquinolones in the amino-defluorination reactions are also different relative to bi- and tricyclic fluoroquinolones.

3-(2-Acylhydrazino)-2-tetra(penta)fluorobenzoylacrylates are readily converted to acylamino-substituted quinolones and, under more forcing conditions, annelation of oxadiazine ring occurs. We have identified the possible cyclization of the mentioned acrylates to 4,5-substituted pyrazoles.

Convenient methods for the synthesis of fluorine-containing quinazolines and their oxa and thia analogues are considered. Data on the prospects for using these compounds in medicine are given. Bibliography — 129 references.

Methods for the synthesis of fluoro-containing benzazoles and benzazines from fluoroarenes (fluoroanilines, fluorobenzoic acids, fluoroacetophenones, fluorophenols, etc.) are described. The potentialities of the most important synthons are considered. Ways of constructing hetero- cycles with fluorine atoms in the annulated benzene fragment are discussed.

The current data on the structure of formazans in crystals and in solutions are considered and some problems of tautomeric and conformational equilibria are discussed. Some novel classes of formazans synthesised over the past decade are presented. The results of structural studies of formazan complexes with various types of metal coordination are generalised. Examples of synthesis of formazan-containing polymers are given. Special emphasis is placed on analytical and practical applications of formazan derivatives. The bibliography includes 155 references. © 2006 Russian Academy of Sciences and Turpion Ltd.

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.

Reactions of 2-aminopyridine and 2-amino-5-methylpyridine with 2,3,4,5-tetrafluorobenzoyl chloride afforded N,N’-diaroylpyridinium salts, which were converted into 6H-pyrido[1,2-a]quinazolin-6-ones by refluxing in toluene in the presence of triethylamine. The angular structure of the tricyclic derivatives obtained was confirmed by 19F and 13C NMR spectroscopy and 2D heteronuclear HetCOR and HMBC experiments.

Ethyl esters of 1-(7-Z-1-ethyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carbamoyl)-5-X-6,7,8-trifluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acids (X = H, F; Z = pyrrolidino-, piperidino-, hexamethylenimino-, morpholino-, thiomorpholino-) have been synthesized by the interaction of quinolone-3-carboxylic acid hydrazides with ethyl esters of 3-ethoxy-2-(polyfluorobenzoyl)acrylic acid . It was shown possible to cyclize intramolecularly the esters obtained with the formation of 1,3,4-oxadiazino[6,5,4-i,j]quinoline derivatives.