COc1ccccc1NC(=O)c1sc2nc(C)c(C(=O)Nc3ccc(C)cc3C)c(-c3ccc(C)o3)c2c1N
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?