COc1cccc(C(=O)C2=C(O)C(=O)N(Cc3cccnc3)C2c2ccco2)c1
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?