COc1ccc(-c2cc(NC=O)c3ncc(-c4cccc(C(C)=O)c4)n3c2)cc1
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?