COC(=O)c1c(C)sc(-c2c(-c3cccc(OC)c3)[nH]c3c2c(=O)[nH]c(=O)n3C)c1O
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?