C=CCN1C(=O)c2ccc(C(=O)N(CC)CC(=O)Nc3cc(Cl)ccc3C)cc2C1=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?