COc1ccc(NC(=O)CSc2oc(-c3ccco3)nc2S(=O)(=O)c2ccc(C)cc2)c(OC)c1
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?