COc1ccc(N2CC3=C(C2=O)C(c2ccc(O)c(OC)c2)NC(=O)N3C)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?