New ultra-short acting hypnotic: synthesis, biological evaluation, and metabolic profile of ethyl 8-oxo-5,6,7,8-tetrahydro-thiazolo[3,2-a][1,3]diazepin-3-carboxylate (HIE-124)

Ethyl 8-oxo-5,6,7,8-tetrahydro-thiazolo[3,2-a][1,3]diazepin-3-carboxylate (HIE-124, 4) is a member of a new generation of ultra-short acting hypnotics. HIE-124 (4) exhibited potent in vivo activity with a rapid onset of action and a short duration of action, with no acute tolerance or noticeable side effects. The metabolic profile of 4 is also performed. HIE-124 (4) has the potential use as a preanesthetic medication, anesthesia inducer, and could be used with thiopental sodium to maintain anesthesia for longer duration.