O=C1c2c(c3c4ccccc4n(CC4CO4)c3c3[nH]c4ccccc4c23)C(=O)N1Cc1ccccc1
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?