Collect. Czech. Chem. Commun. 1988, 53, 1812-1819

Synthesis and biological activity of some basic-substituted 4,9-dihydro-3-methyl-4-oxo-1H(2H)-pyrazolo[3,4-b]quinolines

Stanislav Rádl and Viktor Zikán

Research Institute for Pharmacy and Biochemistry, 130 60 Prague 3


Compounds Ia, Ib were obtained by an alkylation of 4,9-dihydro-6-hydroxy-1,3,9-trimethyl-4-oxo-1H-pyrazolo[3,4-b]quinoline (VIIb) with the respective dialkylaminoalkyl chloride. The same alkylation of 4,9-dihydro-6-hydroxy-2,3,9-trimethyl-4-oxo-2H-pyrazolo[3,4-b]quinoline (VIIIb) yielded compounds IIa and IIb. Similar alkylation of 4,9-dihydro-6-hydroxy-3,9-dimethyl-4-oxo-1H-pyrazolo[3,4-b]quinoline (IXa) and its 6-methoxy derivative (IXb) afforded IIIa-IIId. Compound IV was prepared from 4-chloro-3-methyl-1H-pyrazolo[3,4-b]quinoline (Xa) via its 1-(3-dimethylaminopropyl)derivative (Xb). Compounds VIa, VIb were prepared from 4,9-dihydro-6-hydroxy-3,9-dimethyl-4-oxo-1H-pyrazolo[3,4-b]quinoline (IXc) and the respective dialkylaminoalkyl chloride. The compounds prepared were tested for antiviral activity in vivo in mice against influenza virus A2-Hongkong and encephalomyocarditis virus.