COc1cc(C(=O)OCC(=O)c2c[nH]c3ccccc23)ccc1OCC(=O)N1CCOCC1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?