Cyclocondensation of N-substituted 5-aminopyrazoles with fluorinated 1,3-diketones yielded 4-trifluoromethyl-substituted pyrazolo[3,4-b]pyridines as the only reaction products. The regiostructure of compounds obtained was proved by 1H and 13C NMR homo- and heteronuclear correlation spectroscopy. Characteristic chemical shifts in the 13C NMR spectra of regioisomeric pyrazolo[3,4-b]pyridines were established. © 2008 MAIK Nauka.