COC(=O)c1ccc2c(=O)n(CCCCCC(=O)N3CCN(c4ccc(Cl)cc4)CC3)c(=O)[nH]c2c1
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?