COC(=O)C(C(=O)C(N)=O)c1csc(-n2nc(-c3ccccc3)cc2-c2ccccc2)n1
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?