COc1cccc(-c2nc(S(=O)(=O)c3ccc(C)cc3)c(NCc3ccccc3)o2)c1
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?