COc1ccc(Cl)cc1-n1c(C)cc(C(=O)OCC(=O)N2CC(=O)Nc3ccccc32)c1C
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?