DERIVATIVES OF PYRIDO(3,2-A)-CARBAZOLE HAVING CARDIOTONIC ACTIVITY Russian patent published in 1995 - IPC

FIELD: medicine. SUBSTANCE: desired product has formula 1 where if X-cyan group:a) R₁,R₂ and R₃ =H, essential formula is C₁₆H₁₁N₃O, yield being 88% , melting point being higher 350 C; b) R₁ and R₂ =H and R₃=methyl, essential formula is C₁₇H₁₃N₃O, yield being 73 %, melting point being higher 300 C; c) R₁ and R₂ =H and R₃=phenyl, essential formula is C₂₂H₁₅N₃O yield being 89 %, melting point being higher 300 C; d) R₁=H,R₂=phenyl,R₃=methyl, essential formula being C₂₃H₁₇N₃O, yield being 74 %, melting point being higher 350 C; e) if X-C/O/NH₂, R₁,R₂ and R₃ =H, essential formula is C₁₆H₁₃N₃O₂, yield being 77 % , melting point being higher 350 C. Desired product is prepared by reacting compound having formula I with R₃NH-NH₂·HCl. . Reaction is carried out in the medium of acetic acid in the presence of hydrochloric acid, temperature being from room temperature to boiling point of reaction mixture. Structural formula I and formula II are given in description. EFFECT: improves quality of desired product.