COc1ccc(CC(NC(C)=O)C(=O)NC2CCN(C(=O)c3ccncc3)CC2)cc1OC
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?