COc1cc(/C=C/C(=O)O)cc(S(=O)(=O)Nc2ccc3nc(C)sc3c2)c1OC
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?