DERIVATIVES OF 1,8-BENZO(B)NAPHTHIRIDINE AND PHARMACEUTICAL COMPOSITION ON THEIR BASIS Russian patent published in 1995 - IPC

FIELD: organic chemistry. SUBSTANCE: products: derivatives of 1,8-benzo-(b)-naphthiridine of the formula (I) where R₁ hydrogen, hydroxy-group or alkyl; R₂ hydrogen, alkyl, fluoroalkyl, cycloalkyl containing from 3 to 6 carbon atoms, alkylhydroxy- or alkylamino-group; R₃ phenyl or alkylphenyl possibly substituted with one or several halogen atoms or radicals: alkyl, cycloalkyl, cyano, amino; R₄ hydrogen or fluorine. Reagent 1: piperazine of the formula (II) . Reagent 2: naphthiridine of the formula (III) . Reaction conditions: in the medium of organic solvent in the presence of hydrogen chloride. Synthesized compounds were used in medicine as bactericidal agents. EFFECT: improved method of synthesis. 3 cl