COc1cccc([C@@H]2Oc3ccc(Br)cc3C(=O)[C@H]2OC(=O)NCc2ccc3c(c2)OCO3)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?