3-Amino-4,6-dimethyl-1H-pyrazolo[3,4-b]pyridine (2) has been used as versatile precursor to prepare several heterocyclic compounds. Compound 2 reacted with N-(aryl)-2-chloro-acetamides 3a-d, 4-subsituted benzaldehyde 6a, b and indoline-2,3-dione derivatives 8a-e to yield 4a-d, 7a, b and 9a-e, respectively. The newly synthesized compounds are characterizing by IR, mass and 1H NMR analyses. Ultrasonic irradiations gave a lower reaction time to give products 4a-d, 7a-b and 9a-e in higher yields than those obtained by the previous conventional method where their yields increased from 70-79% to 87-93%. All the newly synthesized compounds were screened to evaluate their anticancer and antioxidant activity. The obtained results showed that compounds 4b and 4c showed a significant activities against the liver cancer cells (HepG-2) with inhibition percentages of 51% and 68.3%, and with IC50 = 120.8 and 73.3 μM, respectively. The antitumor activity of 4b and 4c against HCT116 showed inhibition percentages of 90% and 89.7% with IC50 = 55.6 and 55.7 μM, respectively. Furthermore, the synthesized compounds were examined in vitro for their antioxidant activities against DPPH radicals. The results obtained revealed that all of the tested compounds showed dose dependent DPPH inhibition activities, which were reflected by their IC50. Among the newly synthesized compound 4c showed the highest antioxidant activity with IC50= 72.0 μM.