COc1cc(NC(=O)CN2C(=O)NC(C)(c3ccc4ccccc4c3)C2=O)c(C)cc1[N+](=O)[O-]
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?