CCOC(=O)[C@H]1[C@H]2COc3ccc(Br)cc3[C@@H]2N2C(=O)c3cc(OC)c(OC)cc3NC(=O)[C@@]12C
PSA is a commonly used medicinal chemistry metric for the optimization of a drug's ability to permeate cells. Please predict psa of this molecule.