COc1cccc(-c2cc(NC=O)c3ncc(-c4cccc(C(=O)NCCN(C)C)c4)n3c2)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?