CCC1Sc2ccc(S(=O)(=O)CCC(=O)Nc3c(Cl)cc(OC)cc3OC)cc2NC1=O
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?