COC(=O)c1cc(NC(=O)C2(S(=O)(=O)c3ccc(Cl)cc3)CC2)cc(C(=O)OC)c1
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?