COc1cccc(C2C(C(=O)Nc3ccc(Cl)cc3)=C(C)Nc3nc4ccccc4n32)c1
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?