O=C(CN1CCN(S(=O)(=O)c2ccc(F)c(Cl)c2)CC1)N1CCNC1=O
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?