COc1ccc(CCN2CCC(CNC(=O)c3cnn(-c4cccc(Cl)c4)c3C3CCN(C(=O)OC(C)(C)C)CC3)CC2)cc1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?