COC(=O)c1c(NC(=O)c2ccc(C)c(S(=O)(=O)Nc3ccccc3C)c2)sc2c1CCCC2
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?