CCOc1ccc(S(=O)(=O)Nc2cccc(C(=O)N3CCN(c4cccc(OC)c4)CC3)c2)cc1
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?