O=C(NCc1ccc2c(c1)OCO2)C(=O)Nc1cc2c3c(c1)CC(=O)N3CCC2
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?