We synthesized a series of novel 3-phenyl-4-benzylaminopiperidine derivatives that were identified as potent tachykinin NK1 receptor antagonists by structural modification of the 3-benzhydrylpiperidone derivative through high-throughput screening. N-2-[(3R,4S)-4-(2-Methoxy-5-[5-(trifluoromethyl)-1H-tetrazol-1-yl]benzyl}amino)-3-phenyl-1-piperidinyl]-2-oxoethyl}acetamide ((+)-39) was found to be one