COc1ccc(-c2nc3scc(CCNS(=O)(=O)c4c(C)noc4C)n3n2)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?