COc1ccc(Cl)cc1N(CC(=O)Nc1ccccc1C(=O)N1CCCC1)S(C)(=O)=O
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?