ChemInform Abstract: Fluoro-Containing Heterocycles. Part 4. Synthesis of Benzimidazole Derivatives (original) (raw)

Fluoro-containing Heterocycles. IV. Synthesis of Benzimidazole Derivatives

Russian Journal of Organic Chemistry - RUSS J ORGAN CHEM, 2001

2-Mercapto-5,6-difluorobenzimidazole reacts with aliphatic and alicyclic ketones in acetic acid in the presence of catalytic amount of sulfuric acid to afford fluorinated derivatives of 2,3-disubstituted benz[4,5]imidazo[2,1-b][1,3]thiazoles. Reaction with aromatic a-haloketones occurs in another way: to furnish 2-phenylacylthio-5,6-difluorobenzimidazoles that in the system acetic anhydride-pyridine undergo cyclization into the corresponding fluorinated derivatives of benz[4,5]imidazo[2,1-b][1,3]thiazoles.

Fluoro-containing Heterocycles: VI. New Derivatives of 1,3,4-Thiadiazino[6,5,4-i,j]quinoline

2001

A series of new tricyclic fluoroquinolones was prepared by replacing fluorine atoms in derivatives of 2-R-8-Y-7-oxo-9,10-difluoro-7H-1,3,4-thiadiazino[6,5,4-i,j]quinoline-6-carboxylic acids. In acids and esters containing a hydrogen atom in position 8 occurred replacement of F 10 by amine rests, and in compounds with a fluorine in position 8 was substituted either F 8 or F 10 and F 8 depending on the amine character. 1 H NMR spectrum, d, ppm, coupling constant, Hz ³ 19 F NMR spectrum, d F , ppm,

Synthesis and characterization of heterocyclic substituted fluoran compounds

Journal of the Serbian Chemical Society, 2007

New quinazolinone-substituted fluoran compounds were synthesized by reaction of keto acid, 2'-carboxy-2-hydroxy-4-N-pyrrolidinylbenzophenone with different quinazolinone derivatives in the presence of conc. sulphuric acid. All the synthesized fluoran compounds were characterized by spectroscopic methods (IR, 1 H-NMR and UV-visible spectroscopy) and elemental analysis. The fluoran compounds are colourless or nearly colourless and develop colour on contact with electron-accepting compounds.

Substitutions of Fluorine Atoms and Phenoxy Groups in the Synthesis of Quinoxaline 1,4-di-N-oxide Derivatives

Molecules, 2008

The unexpected substitution of fluorine atoms and phenoxy groups attached to quinoxaline or benzofuroxan rings is described. The synthesis of 2-benzyl-and 2-phenoxy-3-methylquinoxaline 1,4-di-N-oxide derivatives was based on the classical Beirut reaction. The tendency of fluorine atoms linked to quinoxaline or benzofuroxan rings to be replaced by a methoxy group when dissolved in an ammonia saturated solution of methanol was clearly demonstrated. In addition, 2-phenoxyquinoxaline 1,4-di-N-oxide derivatives became 2-aminoquinoxaline 1,4-di-N-oxide derivatives in the presence of gaseous ammonia.

Fluorinated quinolones possessing antituberculous activity

Pharmaceutical Chemistry Journal, 2004

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 . 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.

Fluorine-Containing Heterocycles: XII. Fluorine-Containing Quinazolin-4-ones and Azolo[a]quinazolinone Derivatives

Russian Journal of Organic Chemistry, 2005

Methods for the synthesis of fluorine-containing derivatives of 2-imino-1,3-diphenylquinazolin-4one, imidazo[1,2-a]quinazolin-5-one, pyrazolo[1,5-a]quinazolin-5-one, and [1,2,4]triazolo[1,5-a]quinazolin-5one were developed on the basis of the reaction of tetrafluorobenzoyl chloride with N,N'-diphenylguanidine and aminoazoles.