Cc1ccc2[nH]c(SCC(=O)Nc3ccc(O)c(C(=O)O)c3)nc2c1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?