Structural reassignment of a dibenz[

A screen for compounds with antigiardial activity in the Compounds Australia Scaffolds library identified SN00797640 (supplied structure being 8-acylaminodibenzoxazepinone 1) as a hit compound potent anti-parasitic (concentration 50% growth inhibition of Giardia duodenalis, IC50 0.18 ?M). To further explore structure–activity relationships this series, 1 and analogues, including its 7-acylaminodibenzoxazepinone regioisomer (2), were synthesized assessed anti-Giardia activity. While 2 demonstrated activity, resynthesized other analogues inactive. Comparison spectroscopic physical properties correct to be 7-acylamino 2. These results highlight importance independent synthesis verifying screening hits.