CCOC(=O)c1[nH]c(CSc2nnc(-c3ccncc3)n2CCOC)c(C(=O)OCC)c1C
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?