COc1ccc(N2C(=O)[C@H]3[C@@H](C2=O)[C@@H](C(=O)Nc2ccc(Cl)cc2)N2N=CC=C[C@H]32)cc1
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 pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?