O=C(COc1cc2oc(=O)c3c(c2cc1Cl)CCCC3)NC[C@H]1CC[C@H](C(=O)O)CC1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?