COc1ccc2cc(CNc3ccccc3)c(=O)n(CC(=O)Nc3ccc(C(C)=O)cc3)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?