Discovery and stereoselective synthesis of the novel isochroman neurokinin-1 receptor antagonist ‘CJ-17,493’ Original Research Article

A novel central nervous system (CNS) selective neurokinin-1 (NK1) receptor antagonist, (2S,3S)-3-[(1R)-6-methoxy-1-methyl-1-trifluoromethylisochroman-7-yl]-methylamino-2-phenylpiperidine ‘CJ-17,493’ (compound (+)-1), was synthesized stereoselectively using a kinetic resolution by lipase-PS as a key step. Compound (+)-1 displayed high and selective affinity (Ki = 0.2 nM) for the human NK1 receptor in IM-9 cells, potent activity in the [Sar9, Met(O2)11]SP-induced gerbil tapping model (ED50 = 0.04 mg/kg, sc) and in the ferret cisplatin (10 mg/kg, ip)-induced anti-emetic activity model (vomiting: ED90 = 0.07 mg/kg, sc), all levels of activity comparable with those of CP-122,721. In addition, compound (+)-1 exhibited linear pharmacokinetics rather than the super dose-proportionality of CP-122,721 and this result provides a potential solution for the clinical issue observed with CP-122,721.