COc1cccc(CNC(=O)Cn2cc3c(n2)-c2c(oc(C(=O)N4CCOCC4)c2C)CC3)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?