O=C1NC(=O)C(CCc2ccncc2)(CCc2ccncc2)C(=O)N1Cc1ccccc1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?