COc1ccccc1CCNC(=O)C(=O)NCC1OCCCN1S(=O)(=O)c1cc(C)ccc1C
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?