COc1cc(C(=O)C/C(CCC(=O)Nc2ccc(Cl)cc2Cl)=N/Nc2nnc(C)n2N)ccc1O
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?