COc1ccc(CCNC(=O)C(=O)NCC(c2ccc3c(c2)OCO3)N2CCOCC2)cc1
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?