Collect. Czech. Chem. Commun.
1987, 52, 788-792
https://doi.org/10.1135/cccc19870788
Synthesis of 1,2, and 9-methyl derivatives of 4,9-dihydro-6-methoxy-3-methyl-4-oxo-1H(2H)-pyrazolo[3,4-b]quinoline and 4,9-dihydro-6-hydroxy-3-methyl-4-oxo-1H(2H)-pyrazolo[3,4-b]quinoline and their antiviral activity
Stanislav Rádl and Viktor Zikán
Research Institute for Pharmacy and Biochemistry, 130 60 Prague 3
Abstract
The paper describes syntheses of 4,9-dihydro-6-methoxy-3-methyl-4-oxo-1H(2H)-pyrazolo[3,4-b]quinoline (Ia), its 1-methyl derivative (Ic), 1,9-dimethyl derivative (Ie), 2-methyl derivative (IIa), and 2,9-dimethyl derivative (IIc). Demethylation of these compounds with hydrobromic acid afforded 4,9-dihydro-6-hydroxy-3-methyl-4-oxo-1H(2H)-pyrazolo[3,4-b]quinoline (Ib), its 1-methyl derivative (Id), 1,9-dimethyl derivative (If), 2-methyl derivative (IIb), and 2,9-dimethyl derivative (IId) respectively. 4,9-Dihydro-6-hydroxy-3,9-dimethyl-4-oxo-1H-pyrazolo[3,4-b]quinoline (Ig) was prepared by demethylation of Ie and/or IIc with pyridine hydrochloride. The compounds prepared were tested for antiviral activity in vivo in mice against influenza virus A2-Hongkong and encephalomyocarditis virus.
