N=C1/C(=C\c2ccc(-c3ccc(C(=O)O)cc3)o2)C(=O)N=C2SC=C(c3ccccc3)N12
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?