CC(=O)OC1COC(n2ccc3cc(Br)c([N+](=O)[O-])cc32)C(OC(C)=O)C1OC(C)=O
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?