COc1ccccc1NC(=O)c1cc(C(=O)Nc2ccccc2OC)cc([N+](=O)[O-])c1
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?