A One-Step Synthesis Of [3-H-2]Oxazepam

The proton at 3-position of oxazepam (7-chloro-1,3-dihydro-3-hydroxy-5-phenyl-2H-1, 4-benzodiazepin-2-one) undergoes a deuterium exchange in deuterated alkaline methanol. A base-catalyzed keto-enol tautomerism is proposed to be responsible for the observed deuterium exchange. This simple method is a considerable improvement of the multi-step synthetic procedure reported in the literature.