COc1ccc(Cl)cc1NC(=O)CN(C)C(=O)c1cc(-c2cccs2)nn1-c1ccccc1
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?