COc1cc(OC)c(C(=O)NNC(=O)CN(C)S(=O)(=O)c2ccc(Cl)cc2)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?