COc1ccc(CCN2C(=O)CC(Nc3ccc(N4CCOCC4)cc3)C2=O)cc1OC
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?