CC(=O)c1ccc(N2CCN(S(=O)(=O)c3c(C)[nH]c(C)c3C(=O)N3CCCC3)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?