C=C1CCN([C@H](C(=O)NCc2ccc(OC)cc2)C(C)C)S(=O)(=O)c2ccccc21
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?