Cc1cc(C)nc(NC2=N[C@@H]3CCCC[C@H]3N2C(=O)Nc2cc(Cl)cc(Cl)c2)n1
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?