COc1cc(-c2ccc(NC(=O)NC3CC3)c(OC)c2)ccc1NC(=O)NC1CC1
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?