Pyridinyl aminohydantoins as small molecule BACE1 inhibitors.

A novel class of pyridinyl aminohydantoins was designed and prepared as highly potent BACE1 inhibitors. Compound (S)-4g showed excellent potency with IC(50) of 20 nM for BACE1. X-ray crystallography indicated that the interaction between pyridine nitrogen and the tryptophan Trp76 was a key feature in the S2' region of the enzyme that contributed to increased potency.