COC(=O)CN1C(=O)CSc2ccc(S(=O)(=O)Nc3ccc(C)c(Cl)c3)cc21
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?