COCCn1c(SCC(=O)Nc2nnc(C)s2)nnc1-c1cc2ccccc2cc1O
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?