CCOC(=O)C1=C(Nc2ccc(NC3=C(C(=O)OCC)C(=O)CS3)cc2)SCC1=O
The negative base-10 logarithmic of dissociation constant (pKa) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?