CCOC(=O)CCC(NC(=O)Cc1ccc(Oc2nc3ccccc3nc2-c2ccccc2)cc1)C(=O)OCC
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?