O=C(COC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)c1ccc(Cl)cc1)Nc1ccc2c(c1)OCO2
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?