COC(=O)C1=C(C(=O)OC)C(c2cc(Br)ccc2O)c2sc(O)nc2S1
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?