Some additions for
http://www.bluelight.org/vb/threads/801444-The-quick-guide-on-new-benzodiazepines
With triazolo (and probably imidazolo) derivaitives removing the methyl on the triazolo ring slightly reduces potency but also increases duration.
A Cl an probably any other electronegative group on R4' gives you something that produces anxiety/seizures.
The benzene ring on R5 can be substituted with a pyridine with the N at the second position. This also leads to higher potency.
The benzene ring can be replaced by a non aromatic ring (
https://en.wikipedia.org/wiki/Menitrazepam ) but this reduces potency.
A Cl on R2' leads to slightly more potent but not as hypnotic compounds (fpam vs ppam, flam vs clam)
An extra electronegative sub at R6' leads to active compounds too.
The A ring can be replaced with other aromatic rings (thiophene (etizolam), pyridiine with the N where the R6 C would be (lopiprazepam), pyrazole (zolazepam), ...), many of these don't need strong electro negative groups at R7 (or the position analogus to it.... with eizolam it's actually r2.
Nitro groups at R7 are the most recreational and potent, Chloro are weaker but still fun, Br is more potent than Cl, but not as fun.
R3 can also be substituted with a methyl (meclonazepam)
Most common routes of metabolism include demethylation at R1 (this produces active metabolites), reduction of R7 nitro groups to amino groups (leading to inactive metabolites), hydroxylation at R3 (active) and then glucoridation and excretion (this is also the reason why benzos with a R3 oh have lower hls , hydroxilation of the R1 methyl on triazoo compounds leading to alpha hydroy versions (I think activee).
While the nitrogens on the benuodiazepine part are usually at R1 and R 4, other positions are possible (1 and 5, 2 and 3)