COc1ccc(CNC(=O)c2cc3c(=O)n(Cc4ccc(OC)cc4)ccc3nc2C)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?