COc1cccc(CNC(=O)CN2C(=O)CCn3nc(-c4cn(C)c5ccccc45)cc32)c1OC
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?