O=C1c2ccccc2C(=O)N1CCc1c(-c2[nH]c3ccccc3c2CCN2C(=O)c3ccccc3C2=O)[nH]c2ccccc12
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?