o-2,3,4,5-tetrahydropyridazin-6-yl)pyrazolo[4,3-b] [1,4]benzoxazine (1
) is prepared in two steps from a precursor of bemoradan (2). The comp
ound displays a maximum increase in cardiac force of 256% at 75 mug/kg
intravenously in an anesthetized dog model and has an ED50 of 15 mug/
kg.