CCOc1cc(C(=O)OCC(=O)Nc2ncc(Cl)c(C)c2Cl)ccc1OCC(=O)N1CCOCC1
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?