COc1ccc(Cl)cc1NC(=O)CCN1C(=O)C2C3C=CC(C4CC34)C2C1=O
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?