This azepane derivative, also known as 2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a]azepine, presents as a colorless to pale yellow liquid. Store in a cool and dark place, under inert gas and at ambient temperatures - this substance is air sensitive. 1,8-Diazabicyclo(5,4,0)undec-7-ene is known to be incompatible with oxidizing agents and acids and should not be stored or handled in their vicinity.