CC(C)CC(C(=O)NC(C)(C)C)N(Cc1ccccc1Cl)C(=O)c1snc(C(N)=O)c1N
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?