COc1cc(NC(=O)CSc2ncc(S(=O)(=O)c3ccc(Br)cc3)c(=O)[nH]2)cc(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 negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?