Synthesis of Pyrazolo[3,4-b]pyridine Derivatives and Their In-Vitro and In-Silico Antidiabetic Activities.

In the current study, new pyrazolo[3,4-b]pyridine esters, hydrazides, and Schiff bases have been synthesized starting from 3-methyl-1-phenyl-1H-pyrazol-5-amine. The first step involved solvent-free synthesis of pyrazolo[3,4-b]pyridine-6-carboxylate derivatives (2a-d) with 55%-70% yield in the minimum time frame compared with the conventional refluxing method, which was followed by the synthesis of corresponding hydrazides (3a-d) and hydrazones (4a-e). The structures of the synthesized derivatives were confirmed using element analysis, FT-IR, ¹H NMR, ¹³C NMR, and LC-MS techniques. Synthesized hydrazides (3a-d) and hydrazones (4a-e) were also tested for their in-vitro antidiabetic activity and found that all the compounds exhibited significant antidiabetic activity, while 3c (IC₅₀ = 9.6 ± 0.5 μM) among the hydrazides and 4c (IC₅₀ = 13.9 ± 0.7 μM) among the hydrazones were found to be more active in comparison to other synthesized derivatives. These in-vitro results were further validated via docking studies against the α-amylase enzyme using the reference drug acarbose (200.1 ± 10.0 μM). The results were greatly in agreement with their in-vitro studies and these derivatives can be encouraging candidates for further in-vivo studies in mice models.