O=C(COC(=O)C1CC2C=CC1C2)Nc1cccc(S(=O)(=O)N2CCOCC2)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?