An improvement over pentedrone? In what way? The N-isopropyl substitution is as pointless as N-ethyl, N-benzyl, and N-anything that is metabolised into a primary amine, which is an active metabolite. N-isopropylnorpentedrone isn't going to be much active on its own and Norpentedrone isn't going to be any better in quality than pentedrone, the alpha-propyl makes it what it is, a dopaminergic stimulant mostly. This is going to be shitty for the same reason (more or less actually) 4-MEC or 4-MBC are shitty.