COc1ccc(-c2cc(C(=O)Nc3cc(S(N)(=O)=O)ccc3C)c3ccccc3n2)cc1OC
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?