COc1ccc(N2CCN(C(CNC(=O)C(=O)NCc3ccc4c(c3)OCO4)c3ccco3)CC2)cc1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?