CN1CCc2c(sc3c2C(=O)NC(c2ccc(OC(=O)c4ccc(Cl)cc4)cc2)N3)C1
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?