COc1ccc(OC)c(CNC(=O)Cn2nc(C)c3c(C)n(-c4ccc(C)cc4)nc3c2=O)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?