Cc1cc(OCC(=O)Nc2ccc(N3CCN(C(=O)c4ccco4)CC3)cc2)cc(C)c1Cl
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?