Benzodifurans

The FLY and DragonFLY compounds are 2,5-dimethoxyphenethylamines with the two methoxy groups tied back into fused furan rings — dihydrofuran in the FLYs, fully unsaturated in the DragonFLYs. Locking those oxygens in place raises 5-HT2A affinity sharply, which is why the family is filed under Psychedelics for its agonism rather than beside the open-chain 2C-x compounds it is built from. Bromo-DragonFLY is what gives the family its reputation: onset slow enough that a second dose gets taken before the first has arrived, a duration running well past a day, and strong peripheral vasoconstriction, with ischaemic limb injury reported. 2C-B-FLY shares the scaffold; that it has a milder reputation is not a measured margin.