COc1ccc(N2C(=O)[C@@H]3[C@H]4c5ccccc5C=CN4[C@H](C(C)=O)[C@@H]3C2=O)cc1
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?