COc1cc(-c2noc(CCCC(=O)Nc3ccc(C(N)=O)cc3)n2)cc(OC)c1OC
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?