BChE-IN-25 (4I) is a potent and selective butyrylcholinesterase (BChE) inhibitor with an IC50 of 3.77 µM, showing 22-fold selectivity over acetylcholinesterase (AChE). This small molecule is a valuable research tool for studying BChE's role in neurodegenerative conditions like Alzheimer's disease in both in vitro and in vivo models.