Cl.NC1=C(c2nc(-c3ccc(Cl)cc3)cs2)C(=O)CN1CCCN1CCOCC1
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?