The review surveys the recently obtained data on the synthesis of fluorinated benzazoles and benzazines. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:579–594, 2006; Published online in Wiley InterScience (http://www.interscience.wiley.com). DOI 10.1002/hc.20281

A different type of MnO2-induced oxidative cyclization of dihydrotriazines has been developed. These dihydrotriazines are considered as a “formal” Schiff’s base. This method provided easy access to naphthofuro-fused triazine via the C-C/C-O oxidative coupling reaction. The reaction sequence comprised the nucleophilic addition of 2-naphthol or phenol to 1,2,4-triazine, followed by oxidative cyclization. The scope and limitations of this novel coupling reaction have been investigated. Further application of the synthesized compound has been demonstrated by synthesizing carbazole-substituted benzofuro-fused triazines. The scalability of the reaction was demonstrated at a 40 mmol load. The mechanistic study strongly suggests that this reaction proceeds through the formation of an O-coordinated manganese complex.

In recent years, statistics have shown a considerable increase in the incidence of tuberculosis, which has reached one of the first places with respect to lethality among patients with infectious diseases [1]. The rapid development of drug resistance in microbes, the toxicity and side effects of the existing antituberculous agents, and the lack of bactericidal preparations effective against stable mycobacteria -all these factors stimulate the effort directed toward the search for and development of new drugs.An important group of modern antibacterial drugs, so-called fluoroquinolones, is represented by synthetic derivatives of 4-oxo-6-fluoro-1,4-dihydroquinoline-3-carboxylic acid [2 -4]. Thorough investigation into the properties of fluoroquinolones, especially those with polycyclic structures, revealed some new features of their biological activity spectrum such as antitumor and antiviral properties, including activity with respect to hepatitis C and HIV infection [5 -7]. Since some derivatives of ofloxacin and ciprofloxacin have demonstrated high tuberculostatic properties [8,9], it would be expedient to continue the search for new antituberculous agents in this group of compounds.Previously, we have developed methods for the synthesis of fluoroquinolonecarboxylic acid derivatives of types I -III [10 -12]. This paper presents the results of characterization of a series of such compounds with respect to their tuberculostatic activity.(R 1 , R 2 , R 3 , R 4 , and X are specified in Tables 1 and 2).Quinolones I were obtained using a scheme analogous to that of pefloxacin synthesis, via modification of the initial structure at positions 1, 3, and 7. In particular, quinolonecarboxylic acid Ia, containing the (7-fluoroquinoxalin-6-yl)-amino group in position 1, was obtained by heating 3-ethoxy-2-tetrafluorobenzoylacrylic acid ethyl ester with a hydrazine derivative of quinoxaline in toluene, followed by hydrolysis of the ester group on heating in a mixture of hydrochloric and acetic acids, and by substitution of the pyrrolidine residue for the fluorine atom at position 7. Compounds Ih, Ii, Ik, and Il were synthesized in the same way proceeding from the corresponding acrylates. 3-(4-Dimethylaminophenylmethinimino)carbamoyl derivative Ib was obtained via interaction of 7-morpholino-6-fluoro-1-ethyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrazide with p-dimethylaminobenzaldehyde. 6-Fluoroquinolone Ic (containing the 1,2,3-triazoline fragment in position 7) was obtained via the reaction of 1,3-dipolar cycloaddition of cyclopentanone enamine to 7-azido-6-fluoro-4-oxoquinoline-3-carboxylic acid ethyl ester (see experimental part below). 7-Isoxazolidinyl-substituted 4-oxo-6-fluoro-1,4-dihydroquinoline-3-carboxylic acids (Id -Ig) were synthesized via the reactions of 1,3-dipolar cycloaddition of 4-oxo-6-fluoro-1-ethyl-1,4-dihydroquinoline-3-carboxylic acid 7-azomethinoxide with various unsaturated compounds as described in [11].The synthesis of annelated 1,3,4-thia(oxa)diazino[6,5,4-i, j ]quinolones (II, III) was base...

E) 2 Styryl substituted 6,7 difluoroquinolines and quinoxalines were synthesized by the condensation of the corresponding 2 methylbenzazines with aromatic aldehydes. Photolumines cence of the synthesized 6,7 difluoro 2 styrylbenzazines was studied.

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