COc1ccc(C(=O)C2=C(O)C(=O)N(CCN(C)C)C2c2ccccc2)cc1Cl
The negative base-10 logarithmic of dissociation constant (pKa) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?