COc1ccc2c(c1O)[C@]13CCN(C)[C@H](C2)[C@@H]1CCC(=O)C3
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?