CCn1cc(C(=O)O)c(=O)c2cnc(N3CCN(C(=S)NC(=O)c4ccc(Cl)cc4)CC3)nc21
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?