CN1C(=O)C(CC(N)=O)N(NC(=O)c2ccc(Cl)cc2)C1=S
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?