within this group , 1- [ 2- ( 1h-pyrazol-1-yl ) ethyl ] -4- ( 4-methylthiazol-2-yl ) -4- ( n- phenylpropionamido ) piperidine ( 48 ) , exhibited high analgesic potency , short duration of action , rapid recovery of motor coordination following anesthetic doses , and greater cardiovascular and respiratory safety during anesthesia as compared with opioids fentanyl ( 1 ) and alfentanil ( 2 ) currently in clinical use .
C0015846
fentanyl
C0002026
alfentanil