COC(=O)C(C(=O)C(=O)Nc1c(Cl)cc([N+](=O)[O-])cc1Cl)c1nc2cc(C)c(C)cc2nc1O
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?