O=C(COC(=O)C1CC(=O)N(Cc2ccco2)C1)Nc1nc(-c2ccc(F)cc2)cs1
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?