COc1ccc2nc(Nc3nc(O)cc(CSc4nnc(C)s4)n3)nc(C)c2c1
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?