in short the duration of action has more to do with ADME, than receptor affinity or intrinsic activity. absorption how much is absorbed and how quickly, does it depot in the stomach PO or muscles (IM)? distribution where does it go once it is absorbed
Metabolism, is it destroyed or is it metabolised to active metabolites? what is the ADME of the metabolites.
Excretion, how quickly is it or its metabolites are removed from the system.
as for some in vitro method for estimating duration of action there is no simple way.
doubt that all the dragonflies or the tetrahydrodifuranyls will be long lasting, it depends on the factors above. DOB is long lastiing the difuranyl DOB is also. whether the 4- chloro or methyl congeners are or aren't is unknown by me and I suspect most peope outside nichols inner circle.
(rant) BTW i really hate the stupid nomenclature of dragonflies flys hemiflies it is really f****ing annoying, as it is not always clear what is what, is dragonfly the aromatic difuranyl? and fly the 2C analog or is fly the tetrahydrodifuran and what the F are the butterflies. the hemiflies are even worse there are two possible hemiflies. (/rant)
the benzocyclobutane has the cylobutane attached as part of the benzene ring.
the furanyl pyranyl substances is my poor way of referrring to the compound similar to the difuranyls but where one of the furan rings is replaced by a pyran ring, this would be a bit like the 2 and 5 etos mentioned in pihkal. a source says that these have been synthesised by glennons group who are looking for selctivity 2a vs 2c.
on the subject of magical peas (a bit like magic beans) I have yet to find anyoneto disagree that pure mecaline ( not the complex s pedro of l williamsii extract) is the alpha and the omega of phens.
my point is more that there are limited resources for researching these compounds the simple alkoxy phenethylamine skeleton has been done to death, most of them are not interesting or magical , most of them are going to be illegal everywhere, so what is the point targetting a family of compounds which have already been well explored. its a bit like exploring your back yard really really well in the hope that you will find something amazing (possible but rather unlikely )when there is a whole uncharted world out there. this is simply my opinion and no offense is intended.
In my experience set and setting is far more powerful determinant of a phens action than the substance itself, double blind I cannot tell the difference between 2ci and 2cb by mental effects alone rather I have to rely on knowing the physical side effects of each to give me cues.