O=C(NCc1ccccc1)C1=C[C@@H](c2ccc(Br)cc2)C[C@@H](OCc2ccc(CO)cc2)O1
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?