COC(=O)C1=C(C)NC(C)=C(C(=O)OC)C1c1cccc(/[N+]([O-])=C/c2ccccc2)c1
Molecules with a polar surface area of greater than 140 angstroms squared (Å2) tend to be poor at permeating cell membranes. What's the psa of this molecule?