COc1ccc(NC(=O)N2CCN(C(=O)Nc3ccc(OC)cc3)CC2)cc1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?