The pyrazolo[3,4-b]pyridine derivatives 3 could be prepared by condensing c
ompounds 1 with the 3-aminopyrazolone derivative 2. The pyrazolo[5,2-b]-1,3
-oxazine derivative 11 and polyfunctionally substituted 1,4-dihydropyridine
15, 18 were also synthesized. Some of the obtained compounds were tested f
or their antimicrobial activity.